WASP-19b is an exoplanet whose atmosphere is probably super hot and super poisonous — filled with methane and hydrogen cyanide instead of water. This video explains how astronomers can even begin to guess at the composition of the atmospheres of far away worlds. (Bonus: A soothing elevator music soundtrack!) Read the rest
Last week, Rob told you how scientists announced that they'd found two Earth-like planets orbiting the star Kepler-62. One of those, Kepler-62e, now ranks as the most Earth-like exoplanet we've ever found. Of course, all of this is relative.
What I like about this chart is that it kind of shows you how "Earth-like" doesn't really mean, "Man, that is totally exactly like Earth." Instead, you should translate it more as, "Welp, this is about the closest to Earth that we've found so far." Even Kepler-62e, as you can see, is much larger than the Earth and Mars. And size matters when it comes to actual habitability. As does density — and we don't know what Kepler-62e is made of yet. It's also worth noting that #2 on this list, the infamous Gleise 581g, is really a planet candidate, rather than a planet. We aren't actually certain it exists, just yet.
Popular Science has a neat little breakdown explaining what life might be like on Kepler-62e, if we could go there. But it's worth keeping the context in mind on these Earth-like planets. Don't pack your bags just yet. Read the rest
At his Psychology Today blog, Michael Chorost delves into a question about exoplanets that I've not really thought much about before — how easy they would be to leave.
Many of the potentially habitable exoplanets that we've found — the ones we call "Earth-like" — are actually a lot bigger than Earth. That fact has an effect — both on how actually habitable those planets would be for us humans and how easily any native civilizations that developed could slip the surly bonds of gravity and make it to outer space.
The good news, says Chorost is that the change in surface gravity wouldn't be as large as you might guess, even for planets much bigger than Earth. The bad news: Even a relatively small increase in surface gravity can mean a big increase in how fast a rocket would have to be going in order to leave the planet. It starts with one equation — SG=M/R^2.
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Let’s try it with [exoplanet] HD 40307g, using data from the Habitable Exoplanet Catalog. Mass, 8.2 Earths. Radius, 2.4 times that of Earth. That gets you a surface gravity of 1.42 times Earth.
... it’s amazingly easy to imagine a super-Earth with a comfortable gravity. If a planet had eight Earth masses and 2.83 times the radius, its surface gravity would be exactly 1g. This is the “Fictional Planet” at the bottom of the table. Fictional Planet would be huge by Earth standards, with a circumference of 70,400 miles and an area eight times larger.
Earlier this week, we learned that there is (most likely) at least one planet orbiting the star Alpha Centauri B. If you want to get really in-depth on this discovery, how it was made, and what it means, you should be reading Paul Gilster's Centauri Dreams blog.
I wanted to highlight this image, specifically, in order to quote some particularly evocative writing that Gilster posted yesterday. Cue the stirring music:
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When planet-hunter Greg Laughlin (UC-Santa Cruz) took his turn at the recent press conference announcing the Alpha Centauri B findings, he used the occasion to make a unique visual comparison. One image showed the planet Saturn over the limb of the Moon. Think of this as the Galilean baseline, for when Galileo went to work on the heavens with his first telescope, the Moon was visually close at hand and Saturn a mysterious, blurry object with apparent side-lobes.
Laughlin contrasted that with [this image], showing the Alpha Centauri stars as viewed from Saturn, a spectacular vista including the planet and the tantalizing stellar neighbors beyond. Four hundred years after Galileo, we thus define what we can do — a probe of Saturn — and we have the image of a much more distant destination we’d like to know a lot more about. The findings of the Geneva team take us a giant step in that direction, revealing a small world of roughly Earth mass in a tight three-day orbit around a star a little smaller and a little more orange than the Sun.
Last night, astronomers with the European Southern Observatory announced that they'd found a planet orbiting Alpha Centauri B — an orange star a little smaller and a little less bright than our own Sun. That's important, because, while more than 700 planets have been found outside our solar system, this one — Alpha Centauri Bb (yeah, I know) — is by far the closest. To give you an idea of what we're talking about in distance here, imagine that we are Kansas City and Mars is Toledo. Alpha Centauri Bb is like Tokyo — but you have to get there the long way around and nobody has invented the boat or the plane yet. Basically, it's closer than any other planet we know of outside our solar system, but not really close close. Just 4.37 light years is still more than 25 trillion miles, which is still a long ways away.
Likewise, Alpha Centauri Bb is classified as an "Earth-like" planet, but that shouldn't give you any ideas of colonizing it Zefram Cochrane-style. Bb is way too close to its star for that — closer, even, than Mercury is to our own Sun.
But you should still be excited about this. Terrible, filing-cabinet name aside, Alpha Centauri Bb is jeffing epic. Until now, we didn't think our closest neighboring solar system had any planets at all. And because of the way planets work, writes Lee Billings at the Centauri Dreams blog, this single find means we're much, much more likely to discover other Centaurian worlds. Read the rest
We've talked before about scientists using Rockethub to fund basic laboratory research—stuff that's important, but not likely to lead immediately to new technologies or other marketable products.
It's often hard to find the funding necessary to support this kind of research, and crowd funding is a great way to leverage public interest in science. Better yet, there's now a whole crowd-funding website dedicated specifically to the sciences.
The video above explains one of the projects that's trying to raise money through Petridish right now. David Kipping is a Harvard postdoc and a NASA Carl Sagan fellow. He wants to conduct the first ever survey of exomoons—moons outside our solar system.
Partially, his research is about understanding the universe. Knowing more about exomoons will teach us a lot about how solar systems, in general, work. But it's also about that tickly, exciting possibility of life on other planets. As we all learned from watching Return of the Jedi, it is possible to have a habitable moon. So far, the search for habitable exoplanets hasn't taken moons into consideration. Kipping's study would change that. But to make it work, he needs to buy a supercomputer. And for that, he needs your help. Kipping is within $3500 of his goal and has 14 days left to go.
Find lots more scientific research that needs your support.
Kepler-22b is a newly confirmed exoplanet, orbiting a Sun-like star 600 light years away from Earth. The exoplanet sits in the "habitable zone"—a range of orbits around a star that are, based on what we know about life on Earth, most likely to provide the right conditions for life to happen.
That is pretty damn cool. But it does not mean there must be life on Kepler-22b. As Phil Plait explains on the Bad Astronomy blog, there's a lot we don't know about this exoplanet yet, and "within the habitable zone" is not a guarantee of habitability. Case in point: Our solar system. Earth is within the Sun's habitable zone. But so are Mars and Venus, and you may have noticed that they are not especially teeming with life.
Kepler detects planets when they transit their star, passing directly in front of the star, blocking its light a little bit. The bigger the planet, the more light it blocks. The astronomers going over the data determined that Kepler-22b is about 2.4 times bigger than the Earth. The problem is, that and its distance from its star are all we know. We don’t know if it’s a rocky world, a gaseous one, or what. It may not even have an atmosphere!
Another good post to read on this subject is Matthew Francis' explanation of "habitability" on the Galileo's Pendulum blog. Even the statement, "Kepler 22-b is within the habitable zone," comes along with a lot of assumptions that may or may not turn out to be true. Read the rest