Space – Gizmocrazed – Future Technology News Artificial Intelligence, Medical Breakthroughs, Virtual Reality Thu, 21 Jun 2018 05:34:32 +0000 en-US hourly 1 Here's the Answer That Will Finally Settle the “Is Pluto a Planet?” Debate for Good (Yeah, Right) Wed, 06 Jun 2018 05:31:09 +0000 Here's the Answer That Will Finally Settle the “Is Pluto a Planet?” Debate for Good (Yeah, Right)

Pluto is a beautiful world, with ice mountains, nitrogen glaciers, a haze-layered atmosphere, and methane dunes. But all that complexity does not necessarily make it a “planet.” (Credit: NASA/JHUAPL/SwRI)

I love Pluto. I grew up entranced by this strange little world: What could you be, you rebel that doesn’t seem to follow any of the rules? I even wrote a childhood letter to a local astronomer, offering my homespun hypothesis that Pluto might be a captured fragment of an exploded star. When the New Horizons spacecraft finally revealed the true face of Pluto, I was right there at mission control in Langley, Maryland, to watch the images as they came in.

So I have a lot of sympathy for the Pluto-lovers who were wounded when the International Astronomical Union declared that the 9th planet was not exactly a planet after all, but something called a “dwarf planet.” I also appreciate the sweet irony that the fuss over Pluto’s reclassification stirred up even more interest in the New Horizons encounter. But really, the endless effort to restore Pluto’s planetary status and relegislate the definition of a “planet” is getting tedious. Time to settle this thing.

The problem, as I see it, is that people are asking multiple questions while somehow expecting only a single answer. I’m going to be a little presumptuous here and claim that there are really two answers—and that making sense of those two answers requires breaking them down even further. For you TL;DR types, here are the top-level answers to “is Pluto a planet?”

Answer one: It depends.

Answer two: It’s irrelevant.

It depends. I know, this is an unsatisfying answer, but it’s also a truthful one. There are at least three different things that people (even professional astronomers) mean when they use the term planet. There are historical planets, dynamical planets, and geophysical planets.

Historical planets are those that have entered the common language of science and science writing as planets. Starting in 1801, the first dozen or so objects discovered orbiting between Mars and Jupiter were originally called planets. Then starting in the mid-19th century, astronomers began calling them “asteroids” or “minor planets.” By the early 20th century, popular astronomy writers like Agnes Clerke had embraced that language, and objects like Ceres and Vesta were no longer considered true planets.

Pluto went through a similar evolution. It was classified as a planet about as long as Ceres was, but with some differences. For more than 60 years Pluto seemed like one of a kind, whereas astronomers realized that Ceres was clearly part of a larger group of objects almost right from the start. And Pluto was considered a planet well into the modern era of space exploration, which gave it a special status. Historically, then, Pluto was and remains a planet—one of the nine “classical” planets circling the Sun.

Dynamical planets are defined by how they formed and how they interacted with their surroundings. This is where the IAU’s formal criterion that a planet should have “cleared the neighborhood around its orbit” comes from. The eight major planets are each the dominant objects in their regions, formed by sweeping up the smaller bodies around them. That is obviously untrue of the asteroids. At first, some scientists speculated that the asteroids were the remains of a planet that exploded. By the mid-20th century, people realized that they were actually the leftovers of a population that never accumulated into a planet in the first place.

Here, too, our thinking about Pluto went through a parallel evolution. The discovery of other objects in the Kuiper Belt, starting in 1992, confirmed a growing suspicion that Pluto belongs to a vast population of similar objects orbiting beyond Neptune. Some of these objects, such as Eris, are very similar in size to Pluto. These Kuiper Belt objects are drastically different from Neptune and the other (classical) planets, both in how they formed and in how they got to their current orbits. Dynamically, then, Pluto is definitely not a planet.

The Kuiper Belt and its surrounding region, the Scattered Disk, make up the largest zone of the planetary solar solar system (Credit: NASA)

There is a lot of stuff out there around Pluto in the Kuiper Belt and its surrounding region, called the Scattered Disk. Collectively they make up the solar system’s third zone, after the rocky and gas-giant planets. (Credit: NASA)

Geophysical planets are defined by their size, complexity, and activity. This relates to the IAU’s other criterion that a true planet should be “nearly round.” In academic conversations, planetary scientists routinely refer to any large, round, geologically varied object as a planet. They commonly refer to the moons of Jupiter this way. They commonly refer to our own Moon this way.

When the New Horizons spacecraft flew past Pluto in 2015, it revealed a remarkable world with a haze-layered atmosphere, active glaciers, floating mountains, and slow-churning chasms full of squishy frozen gases. Pluto may be less than 1/5th the diameter of Earth, but it is fully rounded by its gravity and it is wildly complex in its terrain and its processes. Geophysically, then, Pluto certainly qualifies as a planet—a point frequently made by members of the New Horizons team.

So now we have two definitions that say yes, Pluto is a planet and one that says no, it is not. How do you resolve a split verdict like this? The only sensible answer is that you don’t, because trying to force a simple answer onto a complicated question is not just contentious…

It’s irrelevant.

Arguing about the “correct” classification for Pluto will never reach a meaningful resolution, because there is more than one meaningful answer.

Historically and emotionally, Pluto is a planet. No scientific argument will ever change that.

Dynamically, Pluto is not a planet, and there’s no truly convincing way to dispute that, either. Some of Pluto’s defenders argue that the dynamical argument can’t be applied to planetary systems around other stars, but that objection doesn’t hold up. If we find a group of small objects that share similar orbits around another star, we would immediately recognize those as analogs of our asteroid belt or Kuiper belt.

The issue of orbit-clearing is where I find the whole “is it a planet?” debate most counterproductive, because fighting to elevate Pluto back to planetary status only obscures what is most important about it. Pluto is not a loner, but the largest, brightest member of the Kuiper Belt. It is the archetype of an entire class of objects, the Rosetta Stone to the solar system’s third zone.

Now that we have seen Pluto up close, we have a sense of just how rich and complicated those objects can be. Pluto is unusual in having a huge moon, Charon, that is more than 5o% its diameter, along with four smaller satellites. Pluto is also one of the closest, warmest of the Kuiper Belt objects. For these reasons, it may be something of an outlier, more geologically active than the others…but that’s just a guess.

We need to look at more of the little worlds out there to know. When we finally get a clear look at Eris and some of the other intriguing bodies out there (Quaoar, Haumea, Makemake, and so on), we may find that they are active as well. One of the most exciting lessons from New Horizons is that even at temperatures just a few dozen degrees above absolute zero, icy bodies can be geologically active. “Dwarf planet” sounds a little clunky but it’s a useful term for Pluto and its ilk: complex, spherical worlds with a compelling but non-planetary origin story.

Based on their colors and shapes alone, the denizens of the Kuiper Belt appear to be extremely varied. Learning more about that diversity will tell us a lot about how these objects formed, and by extension how the solar system as a whole came together. And all of those variations, all of those different parts of the story, will be measured against Pluto, Kuiper Belt Object #1: not a planet, exactly, but in many ways something even more wonderful.

No Eyes? No Problem. Sea Urchins See with Their Feet Wed, 30 May 2018 05:30:20 +0000 No Eyes? No Problem. Sea Urchins See with Their Feet

Threaten a sea urchin, and you may see it point its spines at you. This defensive response is pretty unremarkable—except for the fact that, if you look closer, you will not see the sea urchin’s eyes. It doesn’t have any.

Sea urchins are the only animals that have vision despite “conspicuously lacking eyes,” write Dan-Eric Nilsson, a biologist at the University of Lund in Sweden who studies animal vision, and his colleagues. In a new study, the researchers gave the spiny sea creatures a kind of eyeless eye exam to find out how good their vision is. They concluded that the animals have pretty poor eyesight, and that it’s actually foot-sight. 

“I think the term ‘tube feet’ may be a little misleading,” Nilsson says. Sea urchins are shaped like squashed spheres, with a hard shell covered in spines. Interspersed among the spines are holes that hide tentacle-like objects called tube feet. But only the feet on the urchin’s underside are for walking. The urchin uses the rest of its tube feet for tasks like attaching to surfaces, flipping itself upright when it gets turned over, and keeping clean, Nilsson says.

A 2011 study of purple sea urchins (Strongylocentrotus purpuratus) found that the animals’ tube feet, strangely, have light-sensitive cells at their bases. Perhaps, the authors wrote, “The entire sea urchin…functions as a huge compound eye.”

In the new study, researchers followed up on this idea by studying long-spined sea urchins (Diadema africanum). They placed the urchins one at a time in the center of a cylindrical tank. Against the wall of this “arena,” the researchers displayed printed images—either a simple black bar, or a pattern of black, white and gray. They used images of different widths like the rows in an eye chart, to test how well the animals could see. In another set of experiments, a monitor directly above the sea urchins displayed black circles of different sizes, like looming predators.

In some cases, the sea urchins moved toward the dark images on the tank walls. This behavior could help urchins in the wild to find shelter when they’re exposed on the seafloor, or to find other urchins and cluster for safety. When an object loomed overhead, alarmed urchins sometimes pointed their spines at it.

Based on which images prompted a response, the researchers found that sea urchin vision isn’t great. Of the 360 degrees around an urchin, an object has to take up somewhere between 30 and 70 degrees before the urchin can see it. Humans can see things at more like 1/60th of a degree, Nilsson says.

“This means that the sea urchin’s picture of the world is very crude in human standards,” Nilsson says. “But it is good enough to guide movements towards suitable structures in their environment.”

The researchers also examined the bodies of long-spined sea urchins up close to see where their tube feet are. Then they estimated the angles at which light hits the feet. They calculated what resolution the animal’s vision would have if all its feet—hundreds in every direction, Nilsson says—worked together as a kind of giant compound eye.

The visual acuity that urchins showed in the tank experiments was within the range that scientists estimated from the tube-foot model. In other words, the animals do seem to see with their feet. A sea urchin is one big, spine-covered eyeball. Its vision might not impress an eye doctor, but for an animal with no actual eyes, it’s not bad.

Photo: A purple sea urchin, by Jerry Kirkhart (via Wikimedia Commons)

665 Days in Space and 47 minutes on TV: A Conversation with NASA Astronaut Peggy Whitson Tue, 29 May 2018 05:30:24 +0000 665 Days in Space and 47 minutes on TV: A Conversation with NASA Astronaut Peggy Whitson

Peggy Whitson took her record-setting 8th spacewalk outside the ISS on March 30, 2017. (Credit: NASA Johnson Space Center)

Life is all about bubbles. Every cell in your body is a bubble, a membrane holding together a miniature world of organelles, ribosomes, and genetic material. Your body itself is another bubble, a skin wrapped around a wet, salty interior that carries a distant memory of the oceans in which our ancestors lived hundreds of millions of years ago. And our entire planet is a bubble, a thin membrane of oxygen-rich air wrapped around a spinning rock warmed by a nearby Sun.

Being able to perceive our reality this way is one of the gifts of spending time with someone like Peggy Whitson, the poetic yet resolutely humble astronaut who has spent 665 days aboard the International Space Station–the longest duration of any American. Her life story is woven into tonight’s final episode of One Strange Rock, an unusual type of nature show that looks back at Earth from the unique perspective of the space explorers who have left it. But what you can see in 47 minutes on screen only scratches the surface of what Whitson has experienced.

In an earlier post I spoke with Leland Melvin, who also participated in the creation of One Strange Rock. Here I have the pleasure of speaking with Peggy Whitson as she concludes her stint on NASA’s post-flight media circuit and tries to decide what to do with the rest of her life, back in the bubble after so much time looking at all of us from the outside.

One of the most striking things about One Strange Rock is the way it brought together a diverse group of astronauts. What was that experience like for you, as a veteran of the team?

It’s been fun doing interviews with the other astronauts, getting hear: “Oh, that’s how he explains it” or “That’s how she thinks about it.” We work together but we don’t necessarily share all those thoughts or ideas. Then when somebody else asks the question you go, “Huh! That’s a cool way to think about that.” Leland [Melvin] talking about family, Mass [Mike Massimino], with his great sense of humor, sharing his experiences in a very different style.

NASA's top astronauts flank the creators of One Strange Rock. Peggy Whitson is in the back row, second from right. (Credit: National Geographic)

NASA’s top astronauts flank the creators of One Strange Rock. Peggy Whitson is in the back row, second from right. (Credit: National Geographic)

What’s next for you, now that you’ve wrapped up a historic career as an astronaut?

[awkward pause] I just finished my six-month post-flight tour. We’ll see how that works out. I’m trying to decide now what I want to do when I grow up!

What are the most common misconceptions you run into when you try to explain  your life aboard the International Space Station?

The #1 misconception? The International Space Station, it’s been up there for 18 years, but most people don’t know that we even have a space station, much less one that has had a presence, human presence, a United States presence, on board for those 18 years.


They don’t even know. They don’t know that there are astronauts from the United States up there right now. That’s…a little disheartening to realize. It doesn’t take away from what we’re doing up there—the research is still very interesting, very exciting.

Wow. Among those who do know, what kind of higher-level misconceptions do you encounter?

Most people assume it’s like the movies, where you can turn gravity on and off when you want to. I show them pictures about how I use my feet to navigate, and about losing my callouses after a couple of months off the bottoms of my feet, developing ones on the tops of my toes from sticking them under the handrails. I try to give them a feel that life adapts and changes to these environments.

Do you then see people light up when they realize just how much we’re doing up there in orbit?

The kids have the excitement, absolutely, and that’s where we need to inspire them. They’re the next-generation explorers. I do see it there. With the adults…sometimes it happens.

Hopefully we will get more and more people interested in doing research in space. I think eventually it’s also going to be a great commercial market. People are going to find out that we can do so much more in space, and it provides a different variable without gravity that is going to provide some new insights. I’m very excited about the future of science in space.

Astronauts have been doing scientific research in space for quite a while. What’s changed?

It’s caliber of science we’re doing on the space station now, and the quantity of science we’re doing. In the timeframe that I’ve been on board the station, the science that we’re doing has reached a much higher level. Some of [the research] had to be simple when we were starting, because that’s all we could support. Now we’ve got some really complex scientific investigations going on.

It’s true, I used to see people rolling their eyes about the level of science on the ISS, but I don’t see that much anymore.

Because most people don’t know the space station exists! [laughs]

Being a biochemist I did a lot of tissue-culture research prior to working at NASA and when I first started working there. The investigations we were doing during this last mission aboard the station: We were looking at the bone cells that build in your body, called osteoblasts. We were looking specifically at how they change in your body during spaceflight, because our bones are continuously remodeling and the cells that tear them down—the osteoclasts—are working just fine. The ones that are building up aren’t.

Now we’re looking at the mechanistic level, at what is happening in those bone cells that’s different in zero gravity, and hopefully learning about how to correct it. If we can better correct bone loss in space, where happens 10 times faster than in a geriatric woman here on Earth, that has ground applications, too. We’re doing studies with rodents, looking at different types of drugs to prevent bone loss. And we’re looking at stem cells, seeing if we can proliferate them in large quantities. Most of the types replicated better in zero gravity. I think there’s going to be some big changes in the future [with space science].

Life outside the bubble: The International Space Station contains a tiny bit of Earth transplanted into space. (Credit: NASA/NatGeo)

Life outside the bubble: The International Space Station contains a tiny bit of Earth transplanted into space. (Credit: NASA/NatGeo)

Do you think the commercial possibilities are strong enough that NASA could privatize part or all of the ISS in the 2020s?

It would be a shame to lose that capability that we have right now. If we can get enough people to invest in the station—pharmaceutical companies or some other people with big money—it is possible that there’d be some commercial partnership thing that would help continue exploration. That could be very exciting.

There are also robotic experiments on the ISS, including the humanoid “robonaut.” Did you work with him at all?

Yeah, I was trying to recover his life, actually. I ended up taking his guts out because he shorted something out and then [the engineers at the Johnson Space Center] wanted all the circuit boards back. So I took his guts out and sent the boards home. [Note: NASA is gearing up to try again with a new version of the Robonaut.]

What are the next big challenges in space exploration? The astronaut interviews on One Strange Rock hint at some future directions.

The show really captured how we’re trying to replicate a whole life support system in low-Earth orbit. Everything is all provided for us here. It’s interesting, the complexity and the interrelatedness of all the pieces that I think is illustrated very nicely in the show. If we go somewhere else, we’re going to have to replicate all of it there.

How much greater are the challenges of a Moon base or a Mars mission compared to what you dealt with on the space station?

There’s a lot more that we have to worry about. Radiation is probably the big one. If we can get [to Mars] faster with nuclear propulsion, that’s going to significantly reduce that radiation risk. Then wherever you get to, you have to have a place where you can bury or partially bury your habitat to give you some radiation protection.

Having a closed-loop life support life system that is very close to a true closed loop, so that we’re not losing any water, is another important thing. On the space station we’re up to about 85 percent right now, which is not bad, but we need to get better if we’re going to spend years getting to Mars, hanging out there, and coming back. We can’t send that much water; even at 85 percent we can’t do it.

We need to get much better at that closed loop system, or go to a place where we can mine water off the surface [like a polar base on the Moon]. Even then, we need to get more efficient so we can carry other things along instead of water. There are going to be lots of things we need to take along!

What about the psychological challenge of going to Mars?

I don’t consider the psychology the biggest part. The success of the crew is going to be based on that, but it’s not going to be a factor that will keep us from going at all. It will be more challenging [than aboard the space station] when you don’t have real-time communication with the ground. We’ve been doing simulations at Johnson Space Center where they do time delays. They end up using a text model system, which turns out to be the most efficient way to handle that time delay, rather than using audio-video all the time.

A journey to Mars is going to feel very different even than going to the Moon [because we won’t be seeing the Earth right outside the window]. The psychology will be: Look at what we’re heading to. Once you lose sight of the Earth, you have Mars to be looking forward to. Leaving Mars might be the hardest part, until you get back to where you can see Earth again.

Whitson in her (former) native environment aboard the ISS on Expedition 50. (Credit: NASA)

Peggy Whitson in her (former) native environment aboard the ISS on Expedition 50. (Credit: NASA JSC)

Beyond better life support, what better technologies do we need to expand the range of human exploration?

New engines is the big thing. [High-performance] ion propulsion needs a nuclear power source. I think our society stagnates if we aren’t continuing to explore, and in order to explore we’re going to need to go there faster. There might also be new kinds of radiation protections that we can do at a biochemical, molecular, cellular level to protect the crews. I’m hopeful that we’ll come up with some new ideas that can help us out there.

What about really far-out ideas, like the researchers who are brainstorming interstellar missions?

It’s important to be thinking about those things. A lot of times you think of things as being science fiction, but the creation of the ideas makes you want to solve them. Then in solving them, they give us greater capability. It’s great that people are trying to find the next thing.

If you had the high-performance rocket and life support, where would you most like to go in the solar system?

In the solar system? Mars is pretty interesting, but maybe Europa. I think there’s good potential for life there, and we should go and check it out. It’s exciting that we’re sending a probe there. It’s a first step. We sent probes to the Moon first. We sent probes to Mars first. It’s part of the process.

I’d go to Mars now if we had a way to get there. Hopefully with SLS [NASA’s new rocket] we’ll get there relatively soon. I’m hopeful. But it may take a Lunar Gateway and some intermediate construction at the Gateway to put all the pieces together and get there.

NASA's Latest Planet Hunter Mon, 07 May 2018 05:31:59 +0000 NASA's Latest Planet Hunter

NASA will be making history again, soon.

Sometime this spring, if all goes as planned, a SpaceX Falcon 9 rocket will carry the Transiting Exoplanet Survey Satellite (TESS) into space. Once in “high-Earth” orbit, the satellite’s instruments will scan the entire sky, hoping to find small planets outside our solar system. The main targets are potentially habitable worlds that are relatively nearby, within a few hundred light-years.

But the mission’s scientific objectives aren’t the only historic part: TESS also stands out because of the orbital path it will follow around Earth, blazing a course through space that no craft has ever flown. Thanks to the orbit’s elongated elliptical shape, says TESS principal investigator George Ricker of MIT, “we can stay away from Earth during observations and get close to Earth to transmit our data, once every 13 or so days.”

These and other orbital attributes will get TESS exactly where it needs to be — with relatively little expenditure of energy and money. That has caught the attention of scientists planning future space missions. It’s a unique orbit that, if not groundbreaking, is certainly “spacebreaking.”

Taking a Dim View Sun, 06 May 2018 05:30:20 +0000 Taking a Dim View

“It’s impossible to understand how that object exists,” says Bothun. “All our models do not produce objects anywhere near Malin 1.” The dim giant proved there might be more to the universe’s galaxies than anyone suspected.

Found and Lost

Galvanized by the discovery of Malin 1, astronomers pored over the previous decades’ photographic plates for hints of unnoticed, low-surface-brightness galaxies. (In fact, they still do — there are a lot of plates.) Although less grand than Malin 1, thousands more materialized throughout the 1990s.

Further aiding in the search were charge-coupled devices (CCDs), a far more light-sensitive imaging technology that took off in the 1980s and dominates astronomy today. “Discovering low-surface-brightness galaxies was a thrilling thing to do,” says Karen O’Neil, then a student of Bothun’s and now the director of Green Bank Observatory in West Virginia. “It’s always fun to go out and look for the unknown.”

Though intriguing, next to the billions of known luminous galaxies, these hundreds of dim ones still didn’t amount to a hill of beans, cosmically speaking. The phantom universe, so far, was just a phantom niche.

But ironically, it was work by Disney himself that ended up slamming the door shut on the field. He helped install a powerful receiver at the Parkes Observatory radio dish in Australia in 1997, hoping to wrangle many Malin 1-esque galaxies and finally blow the lid off the dim universe. In data collected over several years, more than 4,000 concentrations of hydrogen gas turned up — promising candidates as low-surface-brightness galaxies.

By 2005, however, optical telescope follow-ups on these sources suggested they were almost all just hydrogen clouds in normal galaxies. “Not one looked to be a hidden galaxy,” says Disney. The discovery was a crushing result, seeming to prove beyond doubt that Malin 1 and its ilk were just bizarre freaks, not part of a larger phantom universe.

“That killed the subject off,” says Disney. “Even I gave up.”

. . . And Found Again?

But the subject did not give up on him, for other skygazers thought Disney was on to something.

“I was a bit of a figure crying in the darkness,” says Disney, “literally.”

At a 2009 conference in the Caucasus region, Disney met Ukrainian astronomer Valentina Karachentseva, who suggested some of those thousands of hydrogen clouds in the Parkes survey were indeed galaxies. Over her career, through keen eyesight alone, Karachentseva has identified numerous dim galaxies on photographic plates. She told Disney she’d spotted standalone galaxy-like objects right where the Parkes survey had found gas clouds identified as merely extended parts of nearby bright galaxies.

Thunderstruck, Disney returned to Wales and tried something new. He went over calculations affirming just how clustered the universe’s galaxies are. They’re fundamentally social creatures, piling up practically on top of each other, leaving immense, desolate voids between clusters. Could his unseen galaxies be hidden among these huddled galactic herds, with their separate gas clouds mistaken as belonging to the closest, resplendent galactic neighbor?

Disney came to realize that the Parkes observations lacked the resolution, the fineness of detail, to make out dim galaxies tightly bunched with luminous galaxies. He tried to convince study colleagues and an astronomical journal of the possible error, but none was receptive. “I was a bit of a figure crying in the darkness,” says Disney, “literally.”

He eventually found a way to settle the matter. In early 2015 Disney was awarded time on the upgraded, exquisitely sensitive Karl G. Jansky Very Large Array (VLA) of radio dishes in New Mexico. He rescanned a sample of 19 hydrogen clouds from the 4,000 candidates in the Parkes survey. Fourteen of the clouds, it turned out, had no visible counterpart galaxy in the new data.

“Bingo,” says Disney. Straightaway, it was clear that the gas cloud radio wave sources shouldn’t have been lumped together with nearby, optically bright galaxies. He was onto something.

Hiding in Plain Sight

Disney didn’t know what these clandestine objects might be like, and he immediately wanted to follow up with new observations, which are now taking place. In late 2016, using the William Herschel Telescope in the Canary Islands, he spied hints of a dozen newfound, unmistakable dim galaxies.

These objects will increasingly have ample new company, it seems. In a 2015 study, Pieter van Dokkum of Yale University and colleagues announced they had unearthed 47 never-before-seen, Milky Way-sized yet extremely diffuse (spread out, so relatively dim) galaxies in the Coma Cluster of galaxies, among the most studied in astronomy. “This was a complete surprise,” says van Dokkum.

It was not some mammoth new telescope that sussed out these faint objects. The ever-larger telescopes the astronomical community usually clamors for are actually bad at revealing low-surface-brightness objects. These telescopes typically use mirrors, which capture more random, unwanted light, burying any faintly emitting objects. Instead, van Dokkum found his galaxies by grouping eight 400-millimeter lenses into a contraption resembling an insect’s compound eye. Indeed, the project’s name, Dragonfly, comes from van Dokkum’s hobby of taking pictures of the insect.

Alan Stern on the Pluto Revolution, the Psychology of Persistence, and “Chasing New Horizons” Sat, 05 May 2018 05:30:17 +0000 Alan Stern on the Pluto Revolution, the Psychology of Persistence, and “Chasing New Horizons”

In the 1970s, the original version of the Voyager mission was supposed to include a Pluto flyby–and Alan Stern worked through many failed attempts to launch a Pluto mission in the decades since. (Graphic: Jason Davis/The Planetary Society)

On July 14, 2015, the New Horizons spacecraft swept past Pluto, returning eye-popping images of the dwarf planet and its huge (relatively speaking) moon, Charon. At the time, the best existing images of Pluto showed nothing more than an enigmatic blur. New Horizons revealed a world of astonishing diversity: organics-coated dark patches, ice mountains, nitrogen glaciers, and methane snows, all in a state of astonishing activity considering the temperatures there are only about 40 degrees above absolute zero.

The scientific bonanza from the Pluto flyby was sweet vindication for Alan Stern, principal investigator on New Horizons. Stern spent decades fighting to make a Pluto mission happen, persisting long after it seemed like a hopeless cause. Teaming up with writer and astrobiologist David Grinspoon, Stern tells the full, thorny story in his engaging new book Chasing New Horizons: Inside the Epic First Mission to Pluto. It’s a a tale about space science, yes, but it’s also a reminder of what can happen when you refuse to let dreams die.

Myself, I’ve been chasing Alan for years, knowing that an interview with him would always yield a great story about scientific discovery. In addition to his work with New Horizons, he is a former NASA associate administrator, a private space entrepreneur, and the associate vice president of the Space Science and Engineering Division at Southwest Research Institute. Now he is preparing for New Horizons’ next act, a visit to a mysterious Kuiper Belt object called Ultima Thule (pronounced THOOL-ee) happening this December 31. And–as you will soon see–Stern is already thinking about the next few acts after that.

You’ve been through an epic experience, coming off the Pluto encounter and getting ready for Ultima Thule. How did you balance your work time with time to write this book?

Alan Stern: You don’t balance those things! The free perimeter in the whole equation was my sleep. I really haven’t slowed down on New Horizons or the other missions I’m working on. I was on one of the instruments on Rosetta. I am on the Europa mission science team, and the new Lucy Discovery mission science team. I run Southwest Research’s commercial suborbital program. I’m also board chairman for the Commercial Spaceflight Federation. So yeah, there’s a lot going on.

9781250098962One of the most striking themes in the book is how many times you proposed a mission to Pluto, only to get rejected over and over.

What really counts is that when you get knocked down you stand up again. My saying to that is if the Pluto mission had been a cat, it would have been dead long ago! Cats only get nine lives. We got knocked down 11 or 12 times–I mean, to the point of having to start over. Even after we won approval there was a cancellation attempt. It’s not like New Horizons itself was smooth sailing. We had some near-death experiences.

So is the moral of the story: To succeed, you need to be a persistent mother*cker?

Do have the freedom to actually write that? It cuts both ways, to be quite honest. That’s a positive way of looking at it, and I wasn’t alone. Space flight is a team sport. But also there were times when I was taken aside, with fingers poked in my chest. People said, “This [push for a Pluto mission] is not good for your career. You need to stop this. This is costing you and your early in your career and people won’t forget. You can’t take ‘no’ for an answer.” I had to do some soul searching a couple of times about which way to go.

Was that always your personality—were you always determined to get your way?

In the book I tell a story about when I was a little kid. I was voraciously reading about space exploration, and when I ran out of everything in the library I wrote NASA over and over. All they would do is send me the same little silly pamphlets about space food and spacesuits. I finally had the gumption to call up the head of public affairs at NASA Johnson Space Center. I said, “I just saw the Apollo flight plan on CBS News with Walter Cronkite, and I would like one.”

The guy told me, “Listen, that’s for Walter Cronkite. We can’t just give those away.” He said, “If you were credited press I could justify it. But even a high school newspaper won’t count. You have to write a book or you have to write for a major magazine.” I was 14.

What did you do? You started writing for magazines at age 14?

No, I realized that nobody’s going to hire me to write for a magazine, but I could write a book. So that summer I wrote a book and my grandfather had a secretary type it up. It was about 150 pages, double spaced. We sent it to John McLeish, this guy in public affairs. He took one look at it and basically cried uncle. He called me up and said, I’m sending you the flight plans. That book was never published, of course. I wrote it just to get over the barrier to entry.

Were there any times when you thought, “I give up, this Pluto mission just isn’t going to happen?”

In the fall of 2000, Ed Weiler [associate administrator for NASA’s Science Mission Directorate] canceled what was then called the Kuiper-Pluto Express. He held a press conference and said, not only have we issued a stop-work order but we are not going to study any more Pluto missions. He said it is “dead dead dead”—he repeated it three times. Everything we’d worked on for 11 years was suddenly swept away.

That’s when we started calling in favors. An incredible number of people pitched in across the planetary science community in the U.S. and in Europe. The Planetary Society with Lou Friedman was hugely supportive. Bill Nye was individually supportive. Neil Tyson was supportive. There was a lot of public support to put that Humpty Dumpty back together again.

How do you rebound from being told your mission is “dead dead dead”?

Weiler invented this idea that rather than go back to JPL and try again, that NASA would treat [our Pluto concept] like a new style of mission and to let teams compete for it. He announced in December, 2000, that the agency was going to issue an announcement of opportunity in 30 days. Teams didn’t even know that they would exist had to form out of nowhere over the Christmas holidays and then do all the engineering and science development work it takes to write those proposals. It was a Herculean for everybody involved.

How were you able to pull a whole new Pluto proposal together so quickly?

One thing that you may not appreciate is that I’ve worked on 29 space missions. People typecast me, like on Gilligan’s Island. They think of me as “Mr. Pluto.” They don’t realize the other 28 missions I’ve been on. A lot of the lessons that helped make Pluto happen came from those other experiences.

The iconic image of Pluto and its giant "heart"--an ancient impact filled with nitrogen ice, possibly with liquid water lurking below. (Credit: NASA/JHU-APL/SWRI)

The iconic image of Pluto and its giant “heart”–an ancient impact basin filled with nitrogen ice, possibly with liquid water lurking below. Planetary scientists are still trying to make sense of the wildly diverse terrain on Pluto. (Credit: NASA/JHU-APL/SWRI)

Still, there’s something special about Pluto that kept you so focused. What mad a Pluto mission so much more enthralling than all those others?

There were really three things. One is, scientifically, I’d worked a lot on Pluto and knew it was fascinating. I also knew that we weren’t going to figure it out without getting a space mission. We reached a wall by the early 1990s, after the first Hubble images. There weren’t going to be any future big breakthrough unless we went there.

The second thing is that I have always had a love of exploration for its own sake. The first missions to each planet were always the most prized missions. When I got out of grad school in the 1980s, we didn’t know about the Kuiper Belt, so we used to call [going to] Pluto “the first mission to the last planet.” It would be the the capstone to the reconnaissance the planets—our last train to Clarksville. That was very powerful.

And third, there was the invested effort and the unfair things that happened. At some point, I and others felt that there was a wrong that needed to be righted. There was a time when we were told a cancellation took place because we were over budget—and we didn’t even have a budget! There were instances when we thought, People are doing things for reasons other than what they’re saying.

So partly, you wanted justice for Pluto?

There’s nothing more to get your back up than when you feel wronged. Those things together—the science, the exploration, and the borderline anger some people in this community felt, that we’ve been mistreated—it was a hypergolic combination.

When you started thinking about Pluto, nobody knew about the Kuiper Belt. How did the new discoveries change your view of Pluto?

After Jewitt and Luu’s paper was published in 1993, Pluto went from being a misfit—a fascinating body that didn’t fit the pattern of the terrestrial planets or the giant planets—to being the harbinger of the most populous class of planets in the solar system. What we used to think of the outer planets are now the middle zone of the solar system. There are forensic clues in the Kuiper Belt that the planets rearranged their orbits in a violent way very early on. Those discoveries were transformative.

Pluto rose in stature through that process. Instead of the first mission to the last planet, going there would begin a whole new chapter of exploration.

Then when you got there, Pluto turned out to be highly complex and dynamic, despite a temperature of about -230 degrees C (-370 F). Were you surprised?

I knew would be good. I remember once you tried to pry predictions out of me and I all I’d say was, “We’ll find something wonderful.” But Pluto turned out to be the belle of the ball.

It’s a geologist dream. It’s a cosmochemist’s dream. If you like ocean worlds, well Pluto’s got that, too. If you like a really complicated atmosphere that defies imagination, that’s Pluto. It’s got a spectacular system of satellites. It’s the archetype for this whole new class of small planets in the Kuiper Belt that are just as diverse as the terrestrial planets. On top of all that, it’s got this thousand-kilometer-wide heart on it: a little planet with a big heart that captured people’s imagination.

An artist's impression of what the Ultima Thule flyby may look like. The object appears to be binary or double-lobed. (Credit: NASA/JHU-APL/SWRI/Steve Gribben)

An artist’s impression of what the Ultima Thule encounter may look like when New Horizons sweeps past on December 31, 2018. The object seems to be binary or double-lobed; beyond that, we know very little about it. (Credit: NASA/JHU-APL/SWRI/Steve Gribben)

Here, I’ll try again. What do you expect to see when New Horizons reaches Ultima Thule at the end of this year?

We don’t know enough about it to predict. It’s certainly ancient and pristine, and we’ve never seen anything like it.

Your book is in some ways only the beginning of the story, since there’s still a lot more to learn from the New Horizons mission, right?

Oh yes! We did over 450 separate scientific observations with seven instruments. We looked at all five satellites and Pluto. We’ve been skimming the cream but we haven’t until very recently been doing the in-depth analysis and synthesis and modeling to understand why things are the way they are. It will probably be a decade before the data sets have been thoroughly gone over.

Also, we have we have power and fuel to run New Horizons for another 20 years. We’re currently funded for an extended mission through 2021, but we have every intention of proposing mouthwatering science and maybe another Kuiper Belt flyby in the three years following that. Then we’ll probably be finished with observations of Kuiper Belt objects somewhere around 2024.

There’s another possible flyby after Ultima Thule? That’s news to me.

Like all extended missions, we’re on a tight budget compared to the prime mission. We’re just keeping our heads down making sure that Ultima Thule works out. We’re not really going to think in depth about that mission until a year from now, after the first Ultima Thule papers are out. But we’re the only spacecraft ever planned to go to the Kuiper Belt. We need to milk it for everything we can, because it may be a very long time before something is out there again.

Farther ahead, the instrumentation on New Horizons for studying the heliosphere is very powerful compared to what’s on the Voyagers, so you can look at much finer structures and much quicker time variations. They also don’t have instruments like our dust counter. The space physics community is very interested in are flying out the Sun’s termination shock by the 2030s.

I’ll be the optimist and assume we will return to the Kuiper Belt. Where should we go next?

This is the big question: Should we go back to Pluto and orbit it and study it in depth, or should we go to two or three more dwarf planets and sample the diversity of the Kuiper Belt? Let me give you an example of an architecture that would be spectacular for Kuiper Belt science.

There’s a big push to do missions to Uranus and Neptune. Orbiting both of them is probably not affordable, so people in the community are now talking about combined missions. One would put an orbiter around Neptune. As a part of that it would study [Neptune’s giant moon] Triton, which itself is a Kuiper Belt planet now trapped in orbit around Neptune.

Then we would send a second spacecraft, much like New Horizons, on a Uranus flyby and use Uranus for a gravity assist to another Kuiper Belt planet. In the process Uranus would get a flyby visit, not as in-depth as Neptune, but still a very important step forward. With Triton, Pluto, and this third Kuiper Belt planet we would have really started to look at the diversity of these objects.

For space, astronomy, and physics news as it happens, follow me on Twitter: @coreyspowell

From the Overview Effect to “One Strange Rock”: A Conversation with Leland Melvin Tue, 03 Apr 2018 05:30:33 +0000 From the Overview Effect to “One Strange Rock”: A Conversation with Leland Melvin

Leland Melvin shows the two sides of his passion, with the wonder of the “overview” showing outside his Shuttle window. [Credit: NASA]

It’s hard to think of any modern human activity that has had more of a multiplicative impact on the imagination than space exploration. To date, a grand total of 562 humans have left the Earth—a trivial fraction compared to the 7.6 billion people currently staying put. Yet the image of astronauts voyaging away from their home planet has transformed popular culture, education, even business and politics.

Former NASA astronaut Leland Melvin is a lead agent helping to advance that transformation. In a wide range of appearances, he speaks eloquently about the “overview effect,” the life-changing cognitive shift that comes with seeing Earth from the outside. Most recently, he has participated in the new series One Strange Rock, which embraces that effect by examining the marvels of our world from astronauts’ perspectives.

If there is anyone who can bring the rewards of the overview effect to a broader audience—and help make our society a little better in the process—it is Melvin, who has proven his populist bona fides not just as a public speaker and educator, but also as a wide receiver for the Richmond Spiders…and as a noted dog lover. I spoke with Melvin about his life in space, his life in sports, and his latest efforts to share the epiphany of space exploration.

[For science news with a focus on the human adventure in space, follow me on Twitter: @coreyspowell]

Most people will never experience space travel, but you say that space training is a lot like the more familiar process of sports training. How are they similar?

Melvin: The training for flying in space and the training for the NFL, they’re so similar from a mental standpoint. You are working with a team of people to get a win. For space, getting the win means getting to space safely. In the Space Shuttle, you have four people in the cockpit working together as one unit to make sure that any malfunction that pops up, anything that happens, you can figure it out as a team, you can back each other up, and you can into space safely.

When I was a wide receiver there was a similar kind of relationship. On the fly, you have to make contact with the quarterback. A lot of times it’ll be eye contact because the screaming from the crowd can be so loud that you can’t even hear anything.  When I think about doing this mind meld between the quarterback and the receiver, to change and to do things on the fly, we do the same thing in the Shuttle. There can be so much chatter going on, we may communicate non-verbally by tapping the checklist or by pointing to a bank of switches.

In both situations, there’s that connection. You just know what you’re going to do, you know what you’re going to do as team.

One way to share the feeling of being in space is by using familiar cues: sights, sounds, smells, dogs. (Credit: NASA)

One way to share the feeling of being in space is by using familiar cues: sights, sounds, smells, and of course dogs. (Credit: NASA)

But only one of those situations is life or death.

Hold on, that’s not true. In the NFL, if the quarterback hangs a ball and you go after it, and someone hits you and they drive you down on your neck and you snap your neck, you could be dead, or you could be paralyzed. And with the concussion situation, if someone gets hit hard in the head, that could be lifelong trauma. It could be life-ending in the long run. It might not be as dramatic as in space, where a wrong switch throw on the Shuttle could have hydrazine leaking into an auxiliary power unit and everything explodes. But there is safety and death in both settings.

You had a scary, seemingly career-ending accident during astronaut training. What happened?

I was training In the Neutral Buoyancy Laboratory, in a pressurized suits we use to simulate spacewalking in a neutrally buoyant environment [working in an enormous, NASA-designed swimming pool]. If you’re the kind of person who needs to clear your ears by squeezing your nose with your fingers, you can’t do that because you’re enclosed in this suit with a helmet. The only you can clear is with a Styrofoam block that you put in front of your nose in your helmet, and you press your nose against it to clear your ears.

On the day of training the technician forgot to put that in. When I went down into the pool about 20 feet, I was straining and I was not able to effectively clear. They took me out, popped my helmet off, blood was coming out of my ear. Over the next three weeks my hearing started slowly coming back but my left ear was almost completely gone, and in my right ear I only have speaking frequencies. I was medically disqualified. They told me, you will never fly.

And yet you did make it into space after all. How did you recover?

I believe my brain was rewiring itself to hear again, to have noise discrimination, to be able for me to communicate effectively with others, especially my crewmates up in space. I had to use different techniques. The way that your body adjusts to trauma, it can give you other strengths when you lose something—like when you lose one arm, the other arm gets stronger. Sometimes I feel like I have a kind of Spidey sense! I probably read lips a little. Maybe there’s also a way my skin feels the vibration of communication that I can now interpret.

My episode of One Strange Rock is called Awakenings. It’s about the brain figuring out how to take all the data in with the senses to do things like getting food for your family or getting out of harm’s way. In my case, somehow I was able to hear the calls from my crewmates. When you’re doing a space walk you’ll say, maybe, move me 10 inches starboard, move me one foot port. My brain went into overdrive to make sure that I was capable of doing the task.

How does going into space change your senses? Does that experience also rewire your brain?

It does. In space, once the main engines cut out you don’t have any g’s on your body. Those little rocks in your inner ear [that sense up and down] are now ineffective. Your brain has to shut that data off. And I think people get sick from the conflict between orientations coming from the inner ear, which is wrong, and their eyes. The faster you can filter out that incorrect data, the better off you are.

Just transiting through the station, not bumping into things and knowing what orientation you’re in and how fast you’re accelerating, that body control is something that you have to gain…and it depends on the person. I think because I was an athlete–because I had all this high-end training in how to control my body, running and cutting and having to lower and raise my center of gravity–I think that helped me with my adaptation to microgravity.

What does the overview effect mean to you? Why do you consider it so important?

I want people to think about anything you’re doing that’s bigger than yourself. I think about Katherine Johnson in Hidden Figures. Her discipline and her dedication. I gave her a copy of my book and the first thing she wanted to know from me was, “When are we going to Mars? Who’s doing it?” It just blew my mind to think about this woman who challenged everything in West Virginia. She trained herself from a very little girl to be very exact.

Leland Melvin with Katherine Johnson at NASA's Langley Research Center in 2016 (Credit: Credits: NASA/David C. Bowman)

Leland Melvin with Katherine Johnson at NASA’s Langley Research Center in 2016 (Credit: Credits: NASA/David C. Bowman)

What I want people to know is that the routine, this repetition [of learning to be precise and practiced], is done with joy. I call it the joy of repetition. It is not just about us getting a joy ride into space. It’s about bringing it back home and sharing it with people, especially with children. To share it with them so that we can make our planet a better place. We do it together as one civilization, one family. That’s what I take from my training—bringing us all together.

I’m a big advocate for STEAM [science, technology, engineering, art, math] education. If we’re all STEAM explorers, we take everything we do experientially and turn it into something good.

How can more people share that feeling of being in space?

We have to perfect a way to do it down here, because we’re not going to get millions of people in space unless some really incredible technology change happens. Nothing prepared me for it on the ground. I was in the simulators where you can see all aspects of what looks like to be in space, but you’re still in a 1-g environment.

In orbit, you’re looking out the window at Earth, and you’re doing it with people who are already from around the entire world. You’re getting this flavor of Russia as you’re flying over Russia talking to Yuri, or coming over Europe while Hans or Leo are there. You’re making a connection with the people down there because you there with someone who’s from there.

To help people share this overview effect, we will need to have–whether it’s virtually or side by side–astronauts who have been there who can tell the story of what it felt like, what it smelt, like what it tasted like. It’s a very rich part of storytelling. And then have the person’s senses being affected by what they’re seeing.

Your participation in the new series One Strange Rock is part of that?

You know, in One Strange Rock, you’re looking at it in 4K, seeing the planet from space in a very dynamic beautiful compelling way. But imagine if we could have you in a harness where you actually feel like you’re floating over to the Cupola [aboard the International Space Station] and looking out the window. Then what if you could add the other senses in there: You’d have the audio, you’d have a visual, even what it smells like on the space station.

That makes me wonder: What does it smell like in space?

It varies in different parts of the station. When you float through the FGB—the functional cargo block [of the ISS] when I was there—that’s where people will hang their gym shoes and shorts. If you’re floating through there you may catch a whiff of something pretty rich. In the laboratory it might smell a little more like mechanical stuff. Then if you go to the place where we have meals you may smell remnants of the food.

And when you’re coming from outside doing a space walk, there’s this cold metal smell of the EVA suit. Some people say it’s like the smell of sulfur, cold sulfur. But it to me it was like hot metal, but cold. It’s hard to describe.

Now imagine pumping in those smells [while watching a TV show or movie about space travel]. And also playing with temperature. If you’re now coming into the sun in orbit, coming from sunset to sunrise, maybe having the person’s face heat up. VR, sensory suits, suspending people—those are ways you can trick the body to think that you’re really in space. If you add the other senses in there think you can do some good to really help people get that shift.

The overview effect, now available on a TV screen near you. (Credit: National Geographic)

The overview effect, now on the small screen courtesy of Melvin and “One Strange Rock.” (Credit: National Geographic)

Beyond One Strange Rock, what are you doing to let ordinary people have access to the overview effect?

I’m working right now with Constellation. It’s a group of international astronauts–myself, Ron Garan, Nicole Stott, and Anousheh Ansari–trying to get more people involved to tell stories and do presentations to help give that overview effect to people. We’re working on a movie called Orbital right now. We talked to a lot of Apollo astronaut, some Shuttle and Station astronauts, and we’re getting their orbital perspective: What they felt, what they saw, what they believed.

We’re going to use some of the footage to do presentations with large groups of people—to help them see, feel, and taste that overview effect. The storytelling is a huge component of it, but then adding those other sensory elements makes it even more powerful.

Douglas Trumbull [who helped develop the effects for 2001 and Blade Runner] is making little pop-up theaters that can give you all of the visual and sensory experience. You could do other things, maybe make the seats motion-activated. The visuals of what he’s doing are just incredible. He also believes that we’re not going to get enough people up there [in space] to give them the overview effect directly, but we can still help give them the shift.

To Scare Off Predators, Caterpillar Whistles like a Kettle Sun, 25 Mar 2018 05:31:37 +0000 To Scare Off Predators, Caterpillar Whistles like a Kettle

It’s hard to yell “BACK OFF!” when you have no lungs, but this caterpillar has figured out a way. Under attack, the Nessus sphinx moth caterpillar emits a sort of crackling buzz from its mouth. Scientists compare the unusual mechanism to a whistling teakettle. Or a rocket.

Lots of insects make noise, of course, as opening a window on a summer evening will remind you. Conrado Rosi-Denadai, a graduate student at Carleton University, and his coauthors write that sound-making tools in insects “have evolved multiple times and on almost every part of the body wall including legs, wings, mouthparts, head and even genitals.” Insects may rub parts of their tough exoskeleton together, vibrate them, or knock them against something to make their distinctive sounds.

Rather than relying on percussion, humans and other vertebrates tend to make noise using air, which we force out of convenient, squeezable bags in our bodies. Insects don’t have lungs. They breathe through a series of tiny holes along their abdomens. Nevertheless, some insects, such as hissing cockroaches, use air to make sound. But exactly how these noisemakers work isn’t well understood.

Rosi-Denadai and his colleagues studied the sounds of Amphion floridensis larvae. These caterpillars will become Nessus sphinx moths. When attacked—or gently pinched with forceps by a researcher—the caterpillar makes a sound kind of like an annoyed zipper: “BZZZZZZUP, zup zup zup!” (In the second half of this video, the sound is amplified with a bat detector.)

Close-up video showed caterpillars in the lab opening their little mouths while their shrieks came out. The researchers confirmed that the sound came from the mouth by setting up tiny microphones all along a caterpillar’s body and seeing where the noise was loudest:

Screen Shot 2018-03-23 at 10.43.16 AM

Conclusion: sound from mouth, not from butt.

The researchers examined the structures inside the caterpillars’ bodies, then used mathematical models to test different hypotheses for exactly how sound was coming out of them. They ruled out the possibilities that a membrane or chamber inside the caterpillar was vibrating to make the sound. Instead, the model that worked was more like someone blowing across the top of a bottle. Or bottles, really. Two chambers inside the caterpillar’s body—its esophagus and crop—are like the bottles, and a narrow orifice between them is like the bottleneck. The caterpillar makes its alarm sound by forcing air into and out of its gut and between these chambers.

The mechanism is also similar to a teakettle, the authors write, which whistles as steam builds and is forced through a small hole. But “the best analogy to sound production in vocalizing caterpillars is a rocket engine,” they say. The researchers compare the caterpillar gut mechanism to rocket motors that have large, cylindrical chambers connected by narrow nozzles—which, they write, can lead to “unintended noise problems.”

For the caterpillar, the noise is a solution, not a problem. But scientists still have questions. How does the caterpillar pull air into its gut and squeeze it back out? And how did this method of noisemaking evolve? The authors speculate that using air for sound may have evolved from another caterpillar trick: defensive regurgitation.

Images: Rosi-Denadai et al.

Finding Stephen Hawking's Star—And Finding Your Own Thu, 15 Mar 2018 05:30:19 +0000 Finding Stephen Hawking's Star—And Finding Your Own

In 2008, Stephen Hawking delivered a lecture on “why we should go into space” in honor of NASA’s 50th anniversary. (Credit: NASA/Paul. E. Alers)

When I look at the night sky, I often view the stars not just in space but also in terms of their places in time. Light moves at a finite speed (299,792 kilometers per second, to be precise), so the journey from star to star is a very long one even for a beam of light. When astronomers talk about light years of distance, they are literally describing the number of years it takes for light to travel from those distant stars to your eyeball.

And so when I heard about the death of Stephen Hawking, I couldn’t help thinking about his place in the stars. At some distance from Earth, there is a star whose light (as seen right now on Earth) started its journey at the time when you were born. You can think of that as your birth star. We all have one. Hawking has one–and you can easily see it. His birth star is shining brightly in the evening tonight.

Look high in the south after the end of twilight and you will see the prominent bluish-white star Regulus, the brightest star in Leo (the lion). It shines at the base of a grouping of stars that form a pattern resembling a backwards question mark. In mythology, that pattern is commonly viewed as the outline of the lion’s mane and chest. To Babylonian astrologers, Regulus was the “King Star,” marking the heart of the great beast.

The light you see from Regulus tonight started on its journey to Earth right around the time Stephen Hawking was born. Put another way, if alien astronomers on a planet orbiting Regulus had access to a fantastically powerful telescope that allowed them to watch human affairs on our world, they would just now be witnessing Hawking’s birth.

(Actually, the timing is just a little off. Revised measurements show that Regulus is slightly more distant than previously thought, 79 light years away. That means our hypothetical aliens would be seeing Earth as it was three years before Hawking was born. In three years, they would get to witness his birth, and after that the slow unfolding of his remarkable life.)

If you are more than four years old, you too have an equivalent birth star: a star whose distance in light years roughly matches your age in years. For me it’s Castor, one of the “twin” stars in the constellation Gemini, not far from Leo in the sky.

You can find your own by scanning the list below and finding the star whose distance is closest to your age. That is your birth star, the place where the all-seeing aliens would just now be getting news about your entry into the world. (A caveat here, too. The list is based on an older version of the Hipparcos star catalog. Recent revisions mean that some of the star distances are probably off by a few percent, but the numbers are close and the overall concept is still spot-on.)

A list of all bright stars (greater than magnitude 2.5) within 90 light years of Earth. Look at the distances in the fourth column and find the one closest to your age. (Credit: Wikipedia)

A list of all the bright stars (greater than magnitude 2.5) located within 90 light years of Earth. Look at the distances in the fourth column and find the one closest to your age. You can find the original version of the list here. (Credit: Wikipedia)

All of the stars on the list are bright enough to see with the naked eye, and most of them are visible from the northern hemisphere. You might need to refer to a sky map, and you might need to wait until the right season for your star to come into view. When that happens, though, you get to experience a special kind of connection to the universe.

The photons of light from that star are the same age as you are. You have both been traveling on your life journeys for the same length of time—one of you streaking electromagnetically through space, one of you living a biological life on Earth, both of you the end products of fusion reactions between atomic nuclei.

Another distinctive aspect of your birth star is that it keeps changing. As you get older, the distance corresponding to your age keeps migrating farther and farther from Earth. It sweeps past ever-more distant locations, and so you keep migrating down the list of bright stars.

You can think of this expanding radius as an information bubble that is inflating outward from Earth. When you are born, the information of your existence begins spreading out into the universe at the speed of light. Anything inside that bubble is, in principle, connected to your life. Anything outside that bubble is not.

Regulus, the bright star in the constellation Leo, lies just on the outer boundary of Stephen Hawking's information bubble. (Credit: StarryNight)

Regulus, the bright star in the constellation Leo, lies on the outer boundary of Stephen Hawking’s information bubble. (Credit: StarryNight)

I suspect that this way of looking at the sky would appeal to Stephen Hawking, whose ideas were so strongly tied to novel ways of thinking about black holes, the fate of information, and the nature of time. His life bubble is now 76 light years out into the universe. His death bubble has just formed; see this beautiful memorial by Sir Martin Rees.

The part of the universe that could know Hawking ever lived will keep expanding at the speed of light forever. The information that he existed, and the information encoded in all the profound ideas that he has contributed to the world, will not be lost; Hawking’s own theories support the idea that quantum information cannot be destroyed. So it will all survive, and his life bubble will keep expanding.

We all have our birth stars, and we all have our corresponding information bubbles going out into the galaxy. Someday, perhaps physicists will achieve a true understanding of what happens at the event horizon of a black hole. Perhaps they will figure out whether the Big Bang really emerged from a timeless state that had no beginning, as Hawking theorized in his “no boundary” proposal.

Then those answers and those ideas will form bubbles of their own: more information racing out into the universe, chasing the boundary of Hawking’s own life.


Here's what real science says about the role of CO2 as Earth's preeminent climatic thermostat Tue, 13 Mar 2018 05:30:18 +0000 Here's what real science says about the role of CO2 as Earth's preeminent climatic thermostat

The relatively thin atmospheric cocoon that protects us from meteor impacts and radiation also makes for a habitable climate, thanks to the greenhouse gases it contains — carbon dioxide first and foremost. In this photograph captured by an astronaut aboard the International Space Station on July 31, 2011, the oblique angle reveals the atmosphere’s layers, along with a thin crescent Moon illuminated by the Sun from below the horizon of the Earth. (Source: NASA Earth Observatory)

Whenever I post something here at ImaGeo involving climate change, it’s a good bet that I’ll get a spectrum of critical responses in the comments section. These range from skepticism about the urgency of the problem to outright dismissal of humankind’s influence on climate through our emissions of greenhouse gases.

A recent post here about thawing permafrost releasing climate-warming carbon dioxide into the atmosphere was no exception. For the story, I reviewed dozens scientific research papers, and used information and quotations from two interviews. Based on that reporting, here’s what I wrote at the top of the story:

The coldest reaches of the Arctic on land were once thought to be at least temporarily shielded from a major — and worrisome — effect of a warming climate: widespread melting of permafrost. But a recent study suggests these northernmost Arctic areas are likely to thaw much sooner than expected. That’s concerning because melting permafrost releases climate-warming greenhouse gases.

As always, I expected skeptical pushback — but nothing as extreme as this:

As CO2 has had no noticeable effect on climate in 600 million years, until 15- 20 years ago, when carbon tax was invented, any alleged climatic effects can be ignored.

I took this to mean that a liberal scientific establishment invented the idea that carbon dioxide plays a role in Earth’s climate system to support raising taxes.

Never mind that relatively simple physics worked out in the 1800s, and since corroborated by experiments and observations, show that adding CO2 to the atmosphere should raise Earth’s average temperature.

I ordinarily ignore comments like the one I quote above. Discover is a science magazine, not a platform for political grandstanding. And it is especially not a platform for ideas that run counter to basic physics and more than a century of hard scientific work by generations of researchers.

This is not to say that I and the other writers and editors here at Discover view science as being infallible. Far from it. We recognize that as a human endeavor, science is prone to error born of vanity, preconceived notions, confirmation bias, a herd mentality, etc.  Scientists know this better than anyone, so skepticism is one of their cardinal values. So is the recognition that even today’s most widely accepted theories may have to be modified or even replaced tomorrow if new evidence requires it.

Journalists are also supposed to be skeptical and self-critical. We should frequently ask ourselves things like, “How do I know this? Am I sure? Maybe I should check because I could be deceived by my preconceived notions.”

And so in this case, I thought it would be useful to delve deeper into what scientists know of the link between carbon dioxide and climate over the geologic timescale, and CO2’s overall role as a kind of thermostat for the planet.

I don’t pretend that what follows is a definitive primer on these issues. Not even close. But I thought it might be useful to share what I learned — if for no other reason that it might arm readers with some useful scientific information when they encounter people peddling politics in the name of science.

So, back to that original claim that “CO2 has had no noticeable effect on climate in 600 million years,” the commenter wrote this to support it:

My evidence for my comment, is climate history over 600 million years, during which time, when CO2 increased, global temperature decreased, for several million years, and when CO2 decreased, global temperature increased, also for several millions of years.

He also used a graph originally posted online by someone named Monte Hieb at this website. Hieb has changed the graph a number of times over the years. The following version is one that has been frequently picked up by people who deny the science on humankind’s impact on climate, including such well known figures as Christopher Monckton:


Source: APS Physics

It purports to show that CO2 and climate really aren’t well linked.

When I sought more information about this graph, I landed first on a post at RealClimate by Gavin Schmidt, who heads NASA’s Goddard Institute for Space Studies. From his article, titled “Can we make better graphs of global temperature history?,” I learned that Hieb had hand drawn his temperature record based on the work of a scientist named Chris Scotese. And as Schmidt puts it:

Scotese is an expert in reconstructions of continental positions through time and in creating his ‘temperature reconstruction’ he is basically following an old-fashioned idea . . . that the planet has two long-term stable equilibria (‘warm’ or ‘cool’) which it has oscillated between over geologic history. This kind of heuristic reconstruction comes from the qualitative geological record which gives indications of glaciations and hothouses, but is not really adequate for quantitative reconstructions of global mean temperatures. Over the last few decades, much better geochemical proxy compilations with better dating have appeared . . . and the idea that there are only two long-term climate states has long fallen by the wayside

The “proxy” records Schmidt references are preserved physical characteristics of the environment that stand in for direct measurements — in this case, chemical fingerprints in the geological record of changing climatic conditions. (For more on proxy records, see this explainer.)

Based on Schmidt’s post, here is part of my response to the commenter claiming no link between CO2 and climate:

You are deluded by hubris — the idea that by reading one graph of suspect origin you know better than an entire scientific community consisting of literally thousands of researchers, operating over many decades and doing the actual hard work of science — and holding up their findings to rigorous review by expert peers.

I went on to say this:

. . . your alleged “evidence” is a graph, in part hand-drawn, posted to a website that hasn’t been updated in six years by an obscure person with no discernible expertise in this area, and based on the work of a scientist who is not an expert in paleo temperature reconstructions and whose ideas were long ago supplanted by better work based on actual physical proxy records.

I then pointed him toward an example of real researchers doing the truly complex and hard work of science — a peer-reviewed paper titled “CO2 as a primary driver of Phanerozoic climate”.

In their paper, the team of five scientists analyzed a wealth of different data to examine the role of CO2 in climate over the past 540 million years. Their conclusions are nuanced — which is to be expected for a system as complex as global climate, and especially when looking at it over such long time periods. But here is the most relevant fundamental finding:

Here we review the geologic records of CO2 and glaciations and find that CO2 was low (<500 ppm) during periods of long-lived and widespread continental glaciations and high (>1000 ppm) during other, warmer periods.

Other scientists have addressed particular details of the geologic record. These include a period of glaciation that occurred during late Ordovician Period. Climate change dismissives say it happened despite sky high concentrations of climate-warming carbon dioxide in the atmosphere 440 million years ago. This, they claim, is proof that CO2 plays less of a role, or even no role, in determining Earth’s climate.

In supporting this claim they use a geochemical model called “GEOCARB” that provides estimates of CO2 concentrations through geologic time. But the critics fail to mention that the data included in the GEOCARB model come in very long time steps of 10 million years. With this in mind, the creators of GEOCARB explicitly warned that their model cannot discern changes in CO2 occurring over periods less than 10 million years long — including shorter-term drops of the kind that scientists have shown likely occurred during the late Ordovician glaciation.

“Thus, exact values of CO2 . . . should not be taken literally and are always susceptible to modification,” GEOCARB’s creators said.

Yet climate dismissives do just that. And they ignore copious evidence gathered by scientists supporting lower CO2 levels in the atmosphere during that period. For example, a 2009 paper in the journal Geology came to the following conclusion, as described by Phil Berardelli in a story in Science:

The rise of the Appalachians plunged Earth into an ice age so severe that it drove nearly two-thirds of all living species extinct. That’s the conclusion of a new study, which finds that the mountains’ rocks absorbed enough greenhouse gas to freeze the planet.

For more details about the Ordovician glaciation and related issues, the website Skeptical Science has an excellent overview. And for a broad overview of  CO2’s role in Earth’s climate over geological history, check out this lecture by Richard Alley, a renowned Penn State geoscientist:

Commenters on my blog also often claim that since the concentration of CO2 in the atmosphere is so low compared to that of water vapor, also a greenhouse gas, it could not possibly play the role of a thermostat. But here, too, rigorous research shows otherwise.

For example, a team of four NASA scientists led by Andrew Lacis and including Gavin Schmidt, found this: “Ample physical evidence shows that carbon dioxide (CO2) is the single most important climate-relevant greenhouse gas in Earth’s atmosphere.”

Yes, water vapor and clouds are the major contributors to Earth’s overall greenhouse effect. And, in fact, a companion study led by Schmidt showed that water vapor and clouds together account for 75 percent, with CO2 coming in at 20 percent, and other non-condensing greenhouse gases making up the rest.

So given that CO2 accounts for just a fifth of Earth’s overall greenhouse effect, what supports the claim that it nevertheless is the most important greenhouse gas?

The answer involves different characteristics of greenhouse gases. When the atmosphere cools enough, water vapor condenses and rains out. By contrast, carbon dioxide, methane and other greenhouse gases do not — they are non-condensing.

The researchers found that without these non-condensing greenhouse gases — CO2 foremost among them — there would be nothing to prevent the atmosphere from cooling enough to cause water vapor to rain out.  And since it is such a potent greenhouse gas, if water vapor were to rain out, the result would be very dramatic cooling. In this way, CO2 may not be as potent a greenhouse gas as water vapor, but it is actually more important.

“Without the radiative forcing supplied by CO2 and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state,” the authors of the first study concluded.

Just how much does carbon dioxide contribute? The second study led by Gavin Schmidt concluded that the CO2 in our atmosphere is itself is responsible for 80 percent of the radiative forcing that sustains Earth’s greenhouse effect.

CO2 and Earth's Energy Budget

Scientists have worked out the fine details of how energy flows through Earth’s atmosphere, as seen in this diagram. It shows how energy contained in sunlight warms our planet, and how this energy becomes temporarily trapped as it flows away from Earth’s surface as longwave infrared radiation. This energy trap produces the greenhouse effect, the main driver of global warming. (Source: Kevin Trenberth, John Fasullo and Jeff Kiehl via UCAR)

This brings me to another claim made by some commenters here at ImaGeo. Climate records show that global temperatures drop before CO2 does as Earth enters an ice age, and visa versa too: Temperatures rise before CO2 as we come out of an ice age. So once again, CO2 cannot be the most important factor.

Scientists have actually long known that something something other than CO2 sets things in motion when Earth enters and emerges from ice ages: shifts in solar radiation reaching Earth due to variations in the Earth’s orientation to the Sun. (These are known as Milankovitch cycles). Then other natural feedbacks kick in — most especially changes in carbon dioxide.

Scientists haven’t fully teased out all of the details yet. But in general, the picture looks like this:

As Earth starts to warm at the end of an ice age due to increased solar radiation reaching Earth, ice sheets and snow begin to contract. These surfaces are very reflective. So as they shrink, less sunlight is reflected back into space. This helps to enhance the warming. The warming causes ocean waters to give up CO2 — because CO2 is less soluble in warmer water. This strongly enhances the warming, which reduces the ice and snow, which causes more warming, which increases the CO2, leading to even more warming.

The bottom line is that a change in the amount of solar energy reaching Earth may get things going, but it’s CO2 that plays the dominant role.

This general picture leaves out some important details, such as the role of fresh water flowing into the oceans as ice sheets melt. A 2012 study led by Jeremy Shakun, now a Boston College climatologist, examined some of these details. Skeptical Science posted an excellent explainer about the results here. But the upshot of the study was this: “While the orbital cycles triggered the initial warming, overall, more than 90% of the glacial-interglacial warming occured after that atmospheric CO2 increase.”

I’ll finish with one recent piece of research in which a team of five scientists examined the role of greenhouse gases in temperature anomalies, including the overall warming trend, since the onset of the industrial revolution.

Here, too, commenters on this blog often claim that since recent periods in Earth’s past were almost as warm as it is now, we can’t know for sure that the CO2 we’ve added to the atmosphere is responsible for the observed recent warming.

But in their paper, published in the journal Scientific Reports, the scientists confirmed that our emissions of greenhouse gases, “especially CO2, are the main causal drivers of the recent warming.”

Earth’s climate is clearly an incredibly complex system. And climate scientists have never contended that they’ve understood all the details, or that their current understanding isn’t subject to revision when new evidence comes along. This is why they continue to do their research – to improve our understanding of how one of Earth’s key life support systems works.

They’ve also never contended that CO2 is the sole factor driving climate changes over geologic history. As we’ve seen, however, it plays a key role: Without the CO2 thermostat, Earth would likely be a proverbial snowball.

And now, we humans have turned the thermostat up, with predictable results that we’re already observing — such as changes to permafrost in the Arctic that got me going on this post to begin with.