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Earth's Corner of the Galaxy Just Got a Little Lonelier
Hugh Pickens writes "Only four stars, including Barnard's Star, are within six light-years of the Sun, and only 11 are within 10 light-years. That's why Barnard's star, popularized in Robert Forward's hard-SF novel Flight of the Dragonfly, is often short-listed as a target for humanity's first interstellar probe. Astronomers have long hoped to find a habitable planet around it, an alien Earth that might someday bear the boot prints of a future Neil Armstrong, or the tire tracks of a souped-up 25th-century Curiosity rover. But now Ross Anderson reports that a group of researchers led by UC Berkeley's Jieun Choi have delivered the fatal blow to those hopes when they revealed the results of 248 precise Doppler measurements that were designed to examine the star for wobbles indicative of planets around it. The measurements, taken over a period of 25 years, led to a depressing conclusion: 'the habitable zone around Barnard's star appears to be devoid of roughly Earth-mass planets or larger ... [p]revious claims of planets around the star by van de Kamp are strongly refuted.' NASA's Kepler space telescope, which studies a group of distant Milky Way stars, has found more than 2,000 exoplanet candidates in just the past two years, leading many to suspect that our galaxy is home to billions of planets, a sizable portion of which could be habitable. 'This non-detection of nearly Earth-mass planets around Barnard's Star is surely unfortunate, as its distance of only 1.8 parsecs would render any Earth-size planets valuable targets for imaging and spectroscopy, as well as compelling destinations for robotic probes by the end of the century.'"
Could be a local hangout.
I love Jesus, except for his foreign policy.
What about Alpha Centauri? I suppose the binary nature of the star system could make it hard to detect any planets there.
If a solar system has only one thing in it and that thing is mostly just relatively undifferentiated hydrogen, that's going to be less interesting that a solar system with a bunch of things in it. (Regardless of any ideas about colonizing or anything else.) It's certainly still possible that there is something fascinating in that solar system, but at the moment, it would have to be something we still can't detect, so it's hard to get as excited about. Planets are fascinating things. They have interesting geology and interesting compositions. They also imply that there is enough mass for things smaller than planets, like comets and asteroids as well.
When the wise man points at the moon, the naive looks at the stars behind. Go to the Moon, extract water, create an atmosphere, grow plants. Nobody says it's easy. But the whole is likely to take less time than to go to a "near" star and find a "livable" planet...
Slashdot, fix the reply notifications... You won't get away with it...
Let's just build a 'tugboat' and take the earth with us and hope the core stays hot enough to keep us from freezing solid. Be ready for a very long night.
“He’s not deformed, he’s just drunk!”
Yeah, but that is not the argument in this story, the argument is not that there are no planets there, the argument is that there are no Earth size (or larger) planets are not found within the 'habitable zone'.
This doesn't mean there are no planets, there are no planetoids, there are no comets, there is nothing there. It means there are no planets like this one or bigger within the 'habitable range', which is another thing that we make various assumptions about.
So to us 'habitable' means some range of temperatures for example, so that water would be in a liquid form. But this does not even mean at all, that there is no planet there, where there is water in liquid form that is not within the 'habitable range' from the star. Can't water be in liquid form due to other conditions, for example because a planet is too hot due to radioactivity and there is liquid water underground?
They ruled out Earth type planets within 'habitable range' that's all.
You can't handle the truth.
A lack of planet on a nearby star does not mean there is nothing around the star
There might still be fragments of ice / rocks / whatever that humankind can use to construct an artificial planet of some kind
Plus, the lack of existing planet means we get to create one, with our own design
Muchas Gracias, Señor Edward Snowden !
Now I'm seriously worried. Every time I played Masters of Orion 2 and I got situated in an area where the closest habitable planet was far away I always got my ass kicked by some civilization that was able to expand quickly. Our only hope is to start developing Deuterium fuel cells, and quickly!
Could this just mean that it eliminates any orientation other than either pole of the solar system facing Earth?
No, if that were the case, you would still see the star "draw" a little bitty circle if anything sizable is orbiting it.
“He’s not deformed, he’s just drunk!”
You say the 700C hellhole of burning sulphuric oceans is "a bit harder" to terraform?
That is a bit of an understatement.
Because if it's larger then gravity will make it uninhabitable, and if it's smaller then it can't hold an atmosphere, which again would make it uninhabitable.
The upper atmosphere of Venus is much more earth-like though. We just need to figure out how to build a floating colony that can withstand winds of 100m/s.
A wookie touched him when he was small.
Seven puppies were harmed during the making of this post.
What do you expect? This end of the Western spiral arm is somewhat unfashionable.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Over millions of years, sure. It takes a little while to dissipate.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
Plus, the lack of existing planet means we get to create one, with our own design
I wish you damn creationists would stop posting here!
The barycenter of sun-earth is only 300 miles from the middle of the sun.
Keep in mind that Barnard's star is only about a seventh of the sun, and much cooler, so the habitable zone is much closer. An earth sized planet in the habitable zone would have a much larger impact on Barnard's Star than Earth does on Sol.
Yes, except the atmospheric pressure at the surface is gigantic and the solar energy that reaches the surface makes it about as bright as Mars. I'd also talk about the sulfuric acid rain, but due to the pressure, it actually doesn't rain below a certain level of the atmosphere.
Venus *might* be habitable if we can strip off most of the greenhouse gasses and reduce the pressure, but it also doesn't have plate tectonics, its whole crust basically inverts when it is time to release heat from its mantle, so that is a big problem. Consequently, the planet also doesn't have much of a magnetic field.
Venus is the planet equivalent of seeing what looks like a hot girl in a crowd, until "she" turns around and you realize it is a really ugly man with long hair and a beard.
A lack of planet on a nearby star does not mean there is nothing around the star
And, even more to the point, a lack of a planet larger than ten times the Earth's mass in an Earth-like orbit, or two times Earth's mass in a close-in (ten day) orbit says nothing about the presence or absence of Earth- mass planets, unless you have a well-accepted theory showing that systems with Earthlike planets must also have Jupiter-like planets, which is a theory we don't have.
That's according to what the actual article says-- ignore the Slashdot summary, it's wrong. http://arxiv.org/abs/1208.2273
And, worse, the mass detection limits are limits on m*sin(i)-- if the orbits are inclined, the planet masses that couldn't be detected would be even larger. (in the limit, if the orbit is face on, it wouldn't have detected planets regardless of how massive they are)
Overall conclusion: This puts limits on planets around Barnard's star, but did not have the ability to detect, and thus did not rule out, Earth-mass planets.
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