Finding mountains on distant alien worlds

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How Astronomers Could Discover Mountains on Distant Planets

Planets too far away to photograph could yield some clues to whether water—and maybe even life—could exist.

For The Daily Beast:

Earth, Venus, Mars, the moon, and Pluto are very different worlds, but they have something in common: mountains. In fact, mountains occur on so many different bodies in the solar system that astronomers are pretty sure many exoplanets—planets orbiting other stars—also have them. And like planets and moons close to home, those mountains can tell us a lot about what’s going on with exoplanets. They might even help us discover how habitable these far-off worlds are.

But first, we have to see exoplanetary mountains. In a new paper to be published in the prestigious journal Monthly Notices of the Royal Astronomical Society, Columbia University astronomers Moiya A.S. McTier and David M. Kipping figured out what it might take to detect mountains on a world too far away to photograph even with our most powerful telescopes.

[Read the rest at The Daily Beast]

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It ain’t aliens — but this weird-looking star is still interesting

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

We Haven’t Found Alien Megastructures… Yet

The mystery formations and data discrepancies of Tabby’s Star turned out to have explanations. But that’s not what’s important about the mystery star.

For The Daily Beast:

For a second, we thought they were aliens.

In the case of Tabby’s Star—the star more formally known as KIC 8462852—the data (an an accompanying photo of towering figures) was weird enough that a few people surmised it maybe pointed to a sign of an alien civilization. The odds were never good, and a paper published earlier this week shows that aliens almost certainly aren’t involved.

Instead, astronomers think the abnormalities are probably either dust orbiting the star, fragments of comets, or even variations in “weather” on the star’s surface.

These possibilities are a lot more boring than aliens, but that doesn’t mean Tabby’s Star isn’t interesting. The very fact that we still don’t know exactly what’s going on (other than “it ain’t aliens”) is itself interesting.

[Read the rest at The Daily Beast]

Discovering new planets with artificial intelligence

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

Thanks to Google AI, Astronomers Have Found New Planets

They’re not habitable, but the dual discoveries change how we’re going to hunt for the next Earth.

For The Daily Beast:

For the first time, NASA has used machine learning to identify two new planets in distant star systems. One of those worlds is the eighth in its system, making that planetary system the largest-known yet discovered.

We know stars can have eight planets already (hello, Solar System!), so that’s no surprise. The excitement comes in how this new world was found: using an artificial intelligence machine learning method known as “neural networks.”

On Thursday afternoon, Christopher Shallue, a senior software engineer at Google Brain, and Andrew Vanderburg, an astrophysicist at the University of Texas at Austin, announced the new worlds in a press conference. It’s the eighth planet orbiting the 90th star in the Kepler observatory’s catalog, so it carries the name Kepler-90i. It’s a smallish, rocky planet orbiting very close to its host star. This method also identified a fifth planet in the Kepler-80 system, described in the same research paper.

[Read the rest at The Daily Beast]

Two weeks in review (October 27-November 9)

The Universal Marathon: 13.8 billion years! You run this race whether you like it or not, so might as well enjoy it.

Evidently I forgot to post one of these roundups last week, so here’s two weeks’ worth of writing all at once! Also, I have a new sticker design you can order, for those of you (like me) who don’t willingly run for exercise, but want to feel you’ve accomplished something anyway. At least in a cosmological sense, we all run this marathon we call existence.

  1. Drown your town, drown the world (Galileo’s Pendulum): My colleague Andrew David Thaler asked how much water would be required to flood the whole world to the height of Mount Everest, so I took up the challenge.
  2. Hellish exoplanet has Earth-like density and composition (Ars Technica): It’s difficult to measure both the mass and the size of exoplanets (planets orbiting other stars), because discovery methods are complementary to each other. A new pair of papers described the first exoplanet with a density similar to Earth’s, meaning it probably has a similar composition. However, the planet is hot enough to melt most rocks. Don’t plan your vacation there.
  3. New LUX experiment: No dark matter in this corner (Ars Technica): Researchers operating the Large Underground Xenon (LUX) dark matter detector announced the results of the first three months of operation. They found: nothing. Well, specifically they found nothing where some other detectors might have found a possible dark matter signature.
  4. Ghosts in the detector: why null results are part of science too (Galileo’s Pendulum): To follow up that previous article, here’s why the LUX detector wasn’t a failure, and definitely why we shouldn’t think dark matter doesn’t exist.
  5. A comment on comments, with cats (Galileo’s Pendulum): Comments on websites have always been a point of some debate. Do we have them? How do we moderate them? What constitutes reasonable commenting, and who makes that decision? Because of an ongoing “debate” between a few vocal people about pterosaur flight (of all things) on an old post about gravity, which I simply don’t have time or willingness to moderate, I decided to close down comment threads on older posts. That riled some people up.
  6. So close, yet so far (Galileo’s Pendulum): The closest star to the Solar System is invisible to the unaided eye, but in many ways it’s a more typical star than the Sun — much less the other stars we see in the night sky.
  7. The census of alien worlds (Galileo’s Pendulum): The Kepler observatory’s primary mission is over, but its legacy lives on. Based on Kepler data, scientists have estimated the possible number of Earth-class planets orbiting at habitable distances from Sun-like stars. Here’s my take on that study.
  8. I don’t believe in science (Galileo’s Pendulum): Oftentimes, big ideas in science — the Big Bang model, evolution, climate change — are regarded as optional, matters of belief. Here are some of my musings about science, belief, and what it means to trust science in the face of bad behavior, fraud, and controversy.
  9. Weekly Space Hangout (Universe Today): Yesterday, I participated in the weekly round-up of space and astronomy news, in conversation with other science writers. Much fun was had!

The New Yorker recently started “Elements”, a science and technology blog. Their most recent contributor is…me! I covered a strange little controversy begun when the International Astronomical Union (IAU), a professional society with over 10 thousand members, decided to pick a fight with a company offering a contest to name exoplanets. That company, Uwingu, decided to fight back, and the exchange highlighted a set of philosophical questions about who gets to name new worlds.

However, the International Astronomical Union, a society of professional astronomers, strongly disapproves of the entire concept, and published a statement to that effect (though without mentioning Uwingu by name). According to its Web site, the I.A.U.’s tasks include serving “as the internationally recognized authority for assigning designations to celestial bodies and surface features on them.” The process of naming new objects is complicated (the Web précis of the document is itself formidable), and the I.A.U. press release claims exclusive rights to decide what a planet is called—even over the wishes of the scientist or scientists who discovered it. [Read more…]

Now, can I get a picture of Eustace Tilley wearing a bowler hat?

Who names the exoplanets? Who gets to decide?

Imagine a planet 7 times the mass of Jupiter, hot enough to glow slightly, and containing dusty clouds of carbon monoxide and water. That planet is HR 8799c, one of the few worlds outside our Solar System which astronomers have been able to image directly. Part of the reason for its weirdness is its youth: the planet is only about 30 million years old, compared to the Solar System’s 4.5 billion-year age. In fact, up until an observation published this week, astronomers couldn’t be sure HR 8799c was even a planet: many of its properties make it look more like a brown dwarf, the star-like objects not quite massive enough to shine via nuclear fusion. Despite its strange aspects, the planet could help astronomers understand how the HR 8799 system formed—and reveal information about the origins of our own Solar System.

Quinn Konopacky, Travis Barman, Bruce Macintosh, and Christian Marois performed a detailed spectral analysis of the atmosphere of the possible exoplanet. They compared their findings to the known properties of a brown dwarf and concluded that they don’t match—it is indeed a young planet. Chemical differences between HR 8799c and its host star led the researchers to conclude the system likely formed in the same way the Solar System did. [Read more…]

Analysis of atmosphere reveals: weird exoplanet is weird

When our Sun runs out of nuclear fuel, it will shed its outer layers, while what’s left of the core will remain as a white dwarf: an object the size of Earth, but far more massive. During the final stages of the Sun’s life, Earth is likely to perish as a habitable world, but that’s not necessarily the case for every planet orbiting a Sunlike star. That’s the basis of a new paper, which posited that white dwarfs may even provide the best hope for detecting extraterrestrial life.

The advantages of these systems would be manifold: a white dwarf is much smaller than a star, so if a planet passes between it and us, far more light is blocked. And Avi Loeb and Dan Maoz proposed that at least some signs of life might have survived the deaths of these stars. The light emitted by the white dwarf could highlight any oxygen in the exoplanet’s atmosphere, which would be seen as a strong hint of life. [Read more…]

Living planets in a stellar graveyard