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.
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.
Does that mean we could land and take off with exactly the same technology we use here, assuming the atmosphere is similar? Actually, no. Another blogger, who who goes by the moniker SpaceColonizer, pointed out that Fictional Planet has a higher escape velocity than Earth. Put simply, escape velocity is how fast you have to go away from a planet to ensure that gravity can never bring you back. For Earth, escape velocity is about 25,000 miles per hour. Fictional Planet has an escape velocity 68% higher. That’s 42,000 miles per hour.
Read the full story at Psychology Today blogs
Thanks to Apollo 18, who also helped with the math for Chorost's post.
Image: Vintage ad via Christian Montone
Just a few minutes ago, researchers with NASA's MESSENGER mission announced the publication of data that strongly suggests the poles of Mercury contain significant quantities of frozen water.
On the one hand, this is not exactly new news. The possibility of water on Mercury has been a topic of research for something like 20 years. And scientific discoveries tend to move in little mincing steps, not giant leaps, so there have been lots of previous announcements about evidence supporting the hypothesis of water of Mercury — including very similar announcements from the MESSENGER team in December 2011 and March 2012. Your life will not change in any significant way because there is frozen water on Mercury. You probably won't even make a note to tell your children where you were the day NASA announced that ice most likely existed there.
But that doesn't mean this news isn't damned exciting. And it doesn't mean that the scientists involved shouldn't be giddy about it. We are, after all, talking about a mission that sent a spacecraft into orbit around another planet and has quite likely found frozen water sitting on a landscape that is hot enough to melt lead. What's more, they think that ice is covered in places by a thin layer of some coal or tar-like organic material. That is huge news. It's going to change textbooks. And because the scientists think both the ice and the organic material got to Mercury via collisions with asteroids and comets, it's going to be an important part of our ongoing efforts to understand how life begins on planets like Earth.
All of this makes for a really nice, topical lead-in to an essay Robert Gonzalez published on iO9 today. It's totally reasonable to be frustrated by the recent whiplash of hearing that Curiosity discovered something "Earth-shattering" on Mars, only to have that announcement quickly revised to something "interesting" and/or "not insignificant". But, Gonzalez argues, it's also reasonable for scientists to look at something that is merely not insignificant from the public perspective and see it, from their own perspective, as groundbreaking. In fact, he says, we want more scientists who get excited about their work, not fewer.
Read the rest
If yesterday's BoingBoing Gift Guide
didn't give you enough holiday ideas, Popular Science has a collection of gifts for aspiring rocket scientists
. Includes meteorite jewelry, a scarf printed with a pattern inspired by measurement systems, and some natty blazers designed by NASA. — Maggie
Maybe somebody who speaks German can explain why this poor goldfish is being tortured. It's certainly interesting to watch the water in its tank float and blob around — while the fish struggles to follow. But I'm really unclear on the point of this particular experiment.
Via Miriam Goldstein
The Curiosity rover comes complete with a mini chemistry lab. It's designed to analyze the composition of Martian soils and Martian air. And, right now, that particular piece of equipment is at the center of a giddy storm of activity. Curiosity has turned up something important — big enough for Curiosity's principal investigator to tell NPR, "This data is gonna be one for the history books."
What is it? NASA's not telling just yet. Right now, researchers are in the process of verifying said exciting data, in order to make sure they aren't deceiving themselves into thinking they've spotted something that isn't really there. That's pretty good policy, given the recent flap around over-hyped studies about Earth-like planets and arsenic-based life.
On the other hand, if you're trying to avoid overhyping something, might I suggest that "We have groundbreaking, world-changing data that we can't tell you about yet," is maybe not the best way to do it.
Pictured: A 360-degree view of Mars, taken by Curiosity on October 5th, from the location where it first started collecting samples of rocks and dirt. NASA/JPL
After a 125-day stay at the International Space Station, NASA's Sunita Williams, Russian astronaut Yury Malenchenko and Aki Hoshide of Japan's JAXA space agency landed in their Soyuz capsule at 07:56 a.m. local time (0156 GMT) northeast of the town of Arkalyk, in the very cold steppes of Kazakhstan. More in an Associated Press bulletin
. — Xeni
Because sometimes nature just likes to mess with you, here's CFBDSIR2149. It's an object in space — a relatively nearby object in space, as evidenced by the fact that this is an actual picture of it — and scientists are pretty sure that it's a planet. If they're right, then CFBDSIR2149 is also a "rogue planet", so called because it doesn't actually orbit a star. Seriously. It's just hanging out in space, doing its own thing.
Also, it's not the first time a rogue planet has been identified.
In fact, these things are probably not even particularly rare. A 2011 study published in the journal Nature estimated that rogue planets might even outnumber normal stars by 2-to-1 in the Milky Way Galaxy.
It's worth noting that rogue planets do not seem to be Earth-like. For instance, CFBDSIR2149 is roughly the size of Jupiter and, with an estimated surface temperature of 850 degrees Fahrenheit, it is not exactly a pleasant place for people. As for rogue planets come from: That's a mystery. One of the things that makes CFBDSIR2149 special, according to Phil Plait, is that it's actually close enough to us that we can collect some good data on the thing.
Read Phil Plait's description of CFBDSIR2149 at the Bad Astronomy Blog
Read the research paper announcing the discovery of CFBDSIR2149
Read about rogue planets in a Science News story from last year
Image: CFHT/P. Delorme
Tim O'Reilly tweeted about this proposal to deflect pesky asteroids on a collision course with earth. I'm reading The Last Policeman so this is even more interesting to me than usual.
Paintballs may deflect an incoming asteroid
In the event that a giant asteroid is headed toward Earth, you'd better hope that it's blindingly white. A brightly colored asteroid would reflect sunlight — and over time, this bouncing of photons off its surface could create enough of a force to push the asteroid off its course.
How might one encourage such a deflection? The answer, according to an MIT graduate student: with a volley or two of space-launched paintballs.
Kim Stanley Robinson’s 2312 is an insanely ambitious novel of life three hundreds years hence, set in a solar system where the Earth continues to limp along, half-drowned, terrified, precarious — and only one of many inhabited places.
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Hurry, hurry, this is your chance to own the Toshiba Satellite Pro that President Bill Clinton used to email John Glenn in space on November 6, 1998. Apparently, the laptop belonged to a member of Clinton's medical staff who helped the president send the email to orbit. The laptop is listed at $125,000. Wonder how much RAM is in it. "Bill Clinton computer -Presidential email on it, to John Glenn in space!"
Said one astronaut on the ISS just now, during the video transmission I screengrabbed these stills from: "We just flew over the big storm down there, hope everyone's doing okay." Source: NASA TV.
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The Curiosity rover can do a lot of things, but nobody is expecting her to find direct evidence of life on Mars. In fact, the hunt for life on the Red Planet has been a pretty stunted one. The last time we really looked was during the Viking missions, which tried to find chemical "footprints" that would exist if there had once been life on Mars, but that could end up on that planet for other reasons, as well. What we got back was a less-than-enthralling "Outlook Hazy. Try Again Later."
Ever since, we've contented ourselves with searching for indirect evidence — assessing the planet for signs that it might once have had the conditions necessary for life to happen. That's important, and it will make direct evidence of life more believable if we ever do find it, but it's not quite the same thing.
But now, DNA sequencing tools have become portable enough (and drilling technology has become powerful enough) that some scientists and Craig Ventner think we could send a probe to Mars which could find buried traces of actual DNA protected in the dirt and sequence that DNA on site.
It's also possible that life hitched a ride between Earth and Mars in their early days. Asteroid impacts have sent about a billion tonnes of rock careering between the two planets, potentially carrying DNA or its building blocks. That could mean that any genetic material on Mars is similar enough to DNA that we have a chance of finding it using standard tests.
Even if we don't, we can set up future sequencers to look for molecules that use alternative sugars or chemical letters in the genetic code. "We're not there yet, but it's not a fundamental limitation," says Chris Carr of the Massachusetts Institute of Technology, who works on the NASA-backed Search for Extraterrestrial Genomes.
Read the rest of the story at New Scientist
"A giant planet with a liquid interior full of liquid beef and pork, into which a thousand earths would fit."
Darren Cullen of Spelling Mistakes Cost Lives and friend Mark Tolson edited together this 'lost episode' of Carl Sagan's Cosmos, about a fabled Meat Planet, with details of its famous pork volcano, Mount Sustenance, "well-known to astronomers since the time of Galileo."
If NASA would focus on the important planets, the delicious bacon-y ones like this, perhaps we'd have a real future in space exploration. Astronomy-gastronomy!
In March 2013, six people will spend four months on Hawaii's Mauna Loa volcano simulating a Mars mission. Funded by the NASA Human Research Program, HI-SEAS
(Hawaii Space Exploration Analog and Simulation) is focused on what future astronauts might eat during long space adventures like a trip to the red planet. More than 700 people with a variety of science/tech/space/health backgrounds applied to participate in the study. Science journalist Kate Greene, a former editor at Technology Review, was one of those selected to be an astronaut "analog." Kate says, "In particular, we are examining the hypothesis that astronauts cannot live by rehydrated foods alone: we will be cooking and baking with shelf-stable ingredients as astronauts on future Mars missions might." Kate will be writing about her experience in various places, including her blog. "Simulated Mars Mission
"Michel's ultimate plan was a dolphin habitat IN SPACE. The dream was called Bluestar and it is about the most awesomely crazy idea I've ever heard
. A ring of laboratories and places to think would surround a sphere of water that contained a population of dolphins who programmed a supercomputer with "their sophisticated sonar systems." — Alexis Madrigal