A team of astonomers announced the discovery of the most "Earth-like" planet yet found outside the solar system, revolving around a star named Gliese 876, just around the interstellar corner, 15 light years away in the direction of the constellation Aquarius. About seven-and-a-half times as massive as Earth, with about twice the radius, it may be the first rocky planet ever found orbiting a normal star not much different from our Sun.
"We keep pushing the limits of what we can detect, and we're getting closer and closer to finding Earths," said team member Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz.
The 150 other extra-solar planets that have been discovered to date have been larger than Uranus, the remote "ice-giant" planet in our own solar system that is about 15 times the mass of the Earth.
"But there's this huge range of sizes and distances that we haven't seen yet, and with the upgrades at Keck, this team is probably going to find a large number of them," Kevin L. Luhman of the Harvard-Smithsonian Center for Astrophysics told the Washington Post. "They're going to have to go back and do the same stars all over again. But I bet they won't mind that."
Gliese 876—a small, red star known as an M dwarf, the most common type of star in the galaxy—is also obited by two larger, Jupiter-size planets. The new planet whips around the star in a mere two days and is so close to the star's surface that its daytime temperature probably tops 400 to 750 degrees Fahrenheit, temperatures far too hot for life as we know it.
The astronomer's ability to detect the tiny wobble the planet induces in the star gives them confidence that they will be able to detect even smaller rocky planets in orbits more hospitable to life.
"This is the smallest extrasolar planet yet detected and the first of a new class of rocky terrestrial planets," said team member Paul Butler of the Carnegie Institution of Washington. "It's like Earth's bigger cousin."
"This planet answers an ancient question," said team leader Geoffrey Marcy, professor of astronomy at the University of California, Berkeley. "Over 2,000 years ago, the Greek philosophers Aristotle and Epicurus argued about whether there were other Earth-like planets. Now, for the first time, we have evidence for a rocky planet around a 'normal' star," he said. Three other purported rocky planets have been reported outside the solar system, but they orbit a pulsar, the flashing corpse of an exploded star.
"Today's results are an important step toward answering one of the most profound questions that mankind can ask: Are we alone in the universe?" said Michael Turner, head of the Mathematical and Physical Sciences directorate at the National Science Foundation (NSF), which provided partial funding for the research.
The team's work, conducted at the Keck Observatory in Hawaii, was also supported by the National Aeronautics and Space Administration (NASA), the University of California and the Carnegie Institution of Washington.
More information on the discovery here.
Article comments
— go to most recent comments1 - Bennett
Good one Eric. I've been watching this story, and frankly failed to recognize it as particularly important. There have been lots of discoveries in the last ten years of planets orbiting other suns, so I figured it was just a matter of time before one was found that was "earth-like".
I was kinda put off from the (and there aren't any real pictures of this new "earth-like" planet yet, just artist renderings) description of this planet because of the surface temps. (and there aren't any real pictures of this new "earth-like" planet yet, just artist renderings)
Show me one that has green hills, blue oceans, and fleecy skies and I'll jump the hell up and down on the story within minutes.
Bennett
2 - Eric Olsen
thanks Bennett, just sounded kind of cool and I didn't see anything else on it here
3 - Carl
The importance is evident enough in that it is the smallest planet yet detected. With improving technology, it will be only a matter of time that we detect a planet similar in size and capabilities to sustain life.
4 - Eric Olsen
right on Carl
5 - Aaman
Good reportage, Eric - and great positioning by Google News - no satire, this.
6 - Eric Olsen
thanks A, we are finally beyond Satiregate
7 - Duane
Gosh, Bennett. I thought you would be more excited by this. It's a major discovery. You can forget about "real pictures" of an Earth-like planet, with rolling hills, babbling brooks, lush forests, and bloodthirsty, acid-spewing aliens. The angular size of Earth at a distance of, say, 15 light-years, is roughly 10,000 times smaller than the best angular resolution currently available. If anything, it would be a blip at that distance. The planets are not found with imaging, anyway. They're found by looking at the Doppler shift of light from the host star, caused by the gravitational perturbations of the orbiting planets. Exquisitely fine measurements.
Thanks for the update, Eric.
8 - Bennett
Eric, I noticed the end of satiregate a few days ago and it gave me quite a lift!
Carl, you are correct of course, that's what the report seems to highlight. Plus it's not a gaseous planet as other detected planets have been. Getting better all the time at the detection game.
Aaman, what is different about the positioning on google for this story?
9 - JR
It is pretty cool, but you might want to mention that that "picture" they published with the story is total fiction... sorry, "an artist's rendition".
The, er, "geology" of such a large rocky planet has got to be interesting. Still not sure how they can say it's rocky with any degree of confidence...
10 - Bennett
Duane - Too many SF books I guess. I take it for granted that there ARE earth-like planets out there. Law of averages and all that. It's interesting of course, but not a "major discovery" in my book. I appreciate the amazing science that went into it's discovery, and applaud the folks that do this research, but it's not going to change anything other than from a knoqledge standpoint.
Please don't get me wrong here, we do need to do this research and report the findings, I'm just more focussed on discoveries within reach of human space exploration, and our own solar system.
That's a fault, I'm sure.
11 - sungoddess
Thanks for this... I'm quite fascinated by the odd things they pick up in Space... let's not forget Sedna too quickly.
12 - Eric Olsen
thanks for all the interesting input - Bennett, for a while it was at the top of the Google News page, I'm guessing our first
13 - Bennett
That's great Eric! I wish I'd have jumped on it last night when the news broke.
[sigh]
Maybe next time. To what do you attribute the google ranking?
14 - Eric Olsen
right place, right time, right story (not overly covered by other sources) - you never know, but I am starting to get a better sense of what might work
15 - Aaman
I grabbed a couple of screenshots when it was up there on GoogleNews - on my post referenced earlier
16 - Eric Olsen
very cool
17 - Brooke Lee
I call dibs!
18 - Eric Olsen
on the planet?
19 - Duane
I think she meant that the planet should be called Dibs. Planet Dibs. Why not? At least it won't be used as a joke referring to parts of the human anatomy. Personally, I would call it Planet Claire, but they didn't ask my opinion -- again.
20 - Eric Berlin
I wonder what The Duke would name the planet...
21 - Eric Olsen
Planet Claire? I heard she came from there.
22 - Bennett
Only The Duke could say. But if I was in The Duke's shoes (dreamin' fool) I'd be thinking something on lines of "Kirstinopolis".
23 - DJRadiohead
If we were to set up a betting pool, my money would be on "Kristinopolis."
24 - Eric Olsen
how cavalierly we bandy about the Duke's most intimate sentiments
25 - Bennett
Yes Eric, but She understands that we are not The Duke, so it's all just background noise of no consequence.