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Scientists Discover Exoplanet Less Than Twice the Mass of Earth
Snowblindeye writes with this excerpt from the European Southern Observatory:
"Well-known exoplanet researcher Michel Mayor today announced the discovery of the lightest exoplanet found so far. The planet, 'e,' in the famous system Gliese 581, is only about twice the mass of Earth. The team also refined the orbit of the planet Gliese 581 d, first discovered in 2007, placing it well within the habitable zone, where liquid water oceans could exist. Planet Gliese 581 e orbits its host star — located only 20.5 light-years away in the constellation Libra ('the Scales') — in just 3.15 days. 'With only 1.9 Earth-masses, it is the least massive exoplanet ever detected and is, very likely, a rocky planet,' says co-author Xavier Bonfils from Grenoble Observatory. Being so close to its host star, the planet is not in the habitable zone. But another planet in this system appears to be. ... The planet furthest out, Gliese 581 d, orbits its host star in 66.8 days. 'Gliese 581 d is probably too massive to be made only of rocky material, but we can speculate that it is an icy planet that has migrated closer to the star,' says team member Stephane Udry. The new observations have revealed that this planet is in the habitable zone, where liquid water could exist. '"d" could even be covered by a large and deep ocean — it is the first serious "water world" candidate,' continued Udry."
I always hear about these sorts of discoveries, of new planets more and more similar to earth, but having almost no astronomy background, I have no idea how significant they are.
How much do we really know about these planets, and how much is guessing? How close are these planets, really, to earth?
This is very interesting but no where near as exciting as finding another Earth like planet. I suppose we will have to wait for the next generation of telescopes before we find it though.
What is a little surprising though is how many planetary systems we have found that are very different to our own. I can't believe ours is unique but perhaps it's quite rare.
I used to have a better sig but it broke.
"could even be covered by a large and deep ocean â" it is the first serious "water world" candidate" ..
Good.. I wonder if we can export Kevin Costner.
"i lost my dignity on a slippery wiener"
Water worlds always have the crappiest minerals. Oh look more alkalines. Yay. It won't be worth spending the fuel to land on Gliese 581 d, much less the cargo hold space. Gliese 581 e might have iron and other metals, but being so close to the star it probably has major hot spots. So that's probably not worth landing on either until we meet the Melnorme and buy some tech off them.
Oh well. Eliminating planets to explore is good too. There's a lot of stars in the sky, you know, and only so much time to explore them before the UrQuan return.
The enemies of Democracy are
If you would like to know more, download Celestia, an open source project to cruise around the universe in 3D.
:-)
Just select "go to object" and type in "gliese 581", you'll get the orbits of the different planets already found too.
The neat thing is, you can just "cruise" around, speed up time to see how stellar objects move, and so on... Quite cool
Any sufficiently advanced incompetence is indistinguishable from malice - Grey's Law
As in Moonraker, we send the sexy geniuses first, right? Or do we send the Telephone Sanitizers and hairdressers, like in HHGG?
Well according to the travel register, you're booked on the first flight! Take that however you want.
The enemies of Democracy are
Only if you eradicate the ewoks first. God those things are annoying. But hopefully tasty.
To state banally, once again it appears that Earth isn't the center of the Universe, or even an extraordinary spot. Sadly, mankind won't be ever capable of communicating with such a distant places. However, speculation about extraterrestrial life isn't pointless. In range of our capabilities and, moreover, not forbidden by limiting condition on light speed, is a spectroscopic measurement of atmospheres belonging to planets beyond the solar system. Thus, in principle probable, it would be a great achievement to find traces of organic matter.
Those are some bold statements: 1) Considering how many planets we have looked at and that we can't find life on any of them this makes Earth very extraordinary.
2) Not ever be able to communicate with distant places? You don't know what we will invent in the future. It may come out tomorrow, or it may come out in 300 years - but to say "never".
3) Speculation about other life is not pointless - it feeds our soul and imagination to wonder if there is something else. If humans thought exploring was pointless we would still be living in Africa, definitely never have crossed the ocean, let alone landed on the moon (something that people, 100 years ago, thought was impossible)
Finding organic material will be hard short of landing on the surface. We couldn't even do searches of Mars without sending a robotic device there, and even then it may miss something. It's hard, and may not get done in our lifetime (thought it might) but it is certainly not pointless or impossible, and considering how rare life is we should consider ourselves (and our planet) to be very rare and special, though hopefully not unique.
I do not support "The Man". I also do not support your irrational stupidity
The science of extra-solar planet detection is very interesting, but speculation about surface conditions that might exist doesn't reflect the science at all, it's just fodder for the media and bloggers.
The only things we know are extremely rough estimates of orbital parameters and mass, although the host star is well characterised. The speculation is conjuring up quite specific images in people's minds, and while fun, they're not justified. It's leading people without an astronomy background astray.
"The question of whether machines can think is no more interesting than [] whether submarines can swim" - Dijkstra
One interesting thing about Gliese 581 d not being made of rock is that it might have almost the same surface gravity as Earth:
Volume of a sphere=(4/3)*pi*radius^3
radius of sphere=((.75/pi)*volume)^(1/3)
volume=mass/density
radius=((.75/pi)*mass/density)^(1/3)
mass=7.5*mass of earth
density=2kg/liter (twice that of water)
acceleration due to gravity=Gravitational constant*Mass of planet/(radius)^2
thus, plug this into google=
(Gravitational constant)*(7.5*mass of the earth)/((7.5*mass of the earth)/(2kg/liter)*.75/pi)^(2/3)
google gives us: 9.7764354 m / s^2
Yay!
Now, we just need a breathable atmosphere! And light-speed spaceships (or faster)!
I think it would be a good idea to send a rocket with a screen and dvd player or something, with a big red button on it that plays it.
Yeah, because if a big thing from another planet lands and I look inside and see a big red button attached to some unknown device, I'm gonna just press that puppy right away :-)
I Am My Own Worst Enemy