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First Earth-Sized Exoplanet May Have Been Found
Adam Korbitz writes "New Scientist is reporting the extrasolar planet MOA-2007-BLG-192Lb — whose discovery was announced just last summer — may actually be the first truly Earth-sized exoplanet to be identified. A new analysis suggests the planet weighs less than half the original estimate of 3.3 Earth masses; the new estimate pegs the planet's size at 1.4 Earth masses. The planet orbits a small red dwarf star, some 3,000 light-years from here, at an orbital distance of 0.62 astronomical units, about the same distance as Venus from our sun. One significance of the planet's discovery is that it points to the probable ubiquity of smaller terrestrial planets in somewhat Earth-like orbits around red dwarf stars, the oldest and most numerous stars in the galaxy. Here is a video report from the discoverers."
Although this may be the first Earth-sized exoplanet, 335 exoplanets are already listed in the Extrasolar Planets Encyclopaedia.
Food for thought.
This game will waste your life. Don't clicky!
I'm all about getting the hell out of here!
Using standard nomenclature, the star hosting the newly discovered planet is dubbed MOA-2007-BLG-192L with MOA indicating the observatory, 2007 designating the year the microlensing event occurred, BLG standing for bulge, 192 indicating the 192nd microlensing observation by MOA in that year and the L indicating the lens star as opposed to the background star further in the distance. The planet maintains the name but adds a letter designating it as an additional object in the star's solar system, so it is called MOA-2007-BLG-192Lb.
Hello MOA-2007-BLG-192Lb. How are you? We're fine thank you.
How's the weather? Would you like to play a game?
"Kill 'em all and let Root sort 'em out"
it got plutoed http://www.urbandictionary.com/define.php?term=plutoed
I know the use of the term 'Earth-sized' brings more views, but hopefully the non-science/tech people out there reading it will realize that that is just a physical comparison and not a suggestion that life is present.
e.g. Venus is also 'Earth-sized' but is highly inhabitable (for life as we know it)
Up, Up, Down, Down, Left, Right, Left, Right, B, A, START
As our techniques become more sophisticated, we will be able to find more planets of a comparable size to our own. Those 335 can be thought of as the 'first wave' of discovered exoplanets. Large bodies close to their parent stars. These planets are interesting for what they can tell us about how solar systems can form.
The next wave of discovered exoplanets will be smaller, say between the sizes of Venus and Neptune, and therefore far more interesting from the perspective of extrasolar life.
Just because it's an earth-sized planet doesn't mean it's Earth-like. Red dwarf stars are very small (no more than half the mass of the Sun). They don't put out much energy so the habitable zones are very small and very close to the planet. Being so close to the sun makes it likely that the planet would be tidally locked (same side always facing the sun) which isn't so good for life. Finally red dwarf stars often have high stellar variation (sometimes fry you, sometimes freeze you), also not so good for life.
So exciting, but keep looking.....
http://en.wikipedia.org/wiki/Habitability_of_red_dwarf_systems
If you are familiar with the work of Charlie Lineweaver's group in AU, you would be aware that not only should Earth-like planets exist but that a significant number of them are older, and potentially more advanced than we are. This might then lead you to explore whether or not Matrioshka Brains (forms of civilizations significantly more advanced that our own exist.) And indirectly to an understanding that extremely advanced stellar civilizations have very different heat signatures (or detection signatures) from our own. Thus the detection of an earth-like planet is not that significant. The detection of a star going dark, signaling a civilization making a Kardashev-Type-I to a Kardashev-Type-II transition -- now that would be interesting.
Since the strength of the gravitational field of a planet is a factor of its mass, and the gravitational pull on the surface is in direct relation to the distance from the center of the planet... could it not be possible to have a planet the size of say, Neptune, with a geological makeup similar to the Earth, that has a lower mass and therefore the acceleration at the surface is exactly 1g (as we understand it here on Earth). That is within the bounds of physics, is it not?
Or maybe the effective gravity is stronger, but the planet spins faster. Faster days as well?
The problem I guess would be the existence of a formation process that actually creates a planet with such a large surface but happens to be mostly rock instead of mostly gas (supposedly gas giants are "failed stars"). If it has a molten iron core, would it not collapse in on itself?
Interesting, imagine a planet with the surface composition and atmosphere of Earth (and supposedly biomass) but 10 or more times the surface. That would be amazing.
Earth might be broken in some ways, but it is (most likely) a lot better environment than anything else out there. Earth is a far better starting position than Mars or whatever and fixing what's broken here would be far more achievable than trying to build a viable human-sustaining ecosystem on some other planet.
On the flip side, the spin-off technologies from making a sustainable habitat off planet would probably do wonders for improving the quality of life on planet. Everything from medical technology to air scrubbing and environmental cleanup, food and nutrition to understanding of local ecology and balancing it, energy technology to waste disposal and recycling, and probably much more.
"Empathise with stupidity, and you're halfway to thinking like an idiot." - Iain M. Banks
This must be the first Slashdot post with a GNAA subject line that's been modded "informative" in years.
Hail Eris, full of mischief...
E pluribus sanguinem
But the doctor says I can't have iced tea. He said nothing about the rest.
Do not mock my vision of impractical footwear
I anticipate that someday science will advance to the point where ordering up your own private garden planet, and a fleet of intelligent and loyal robots to tend it for you, is considered routine. A wormhole network connecting your plant to a set of resource-rich sunless moons will be included at no extra charge.
Everyone will have eternal life and health, lots of friends, and be allowed by their doctors to drink all the ice tea they want.
But we still won't have flying cars.
Specifically, Earth biology wouldn't do well orbiting a red dwarf. Red dwarfs emit most of their energy via thermal convection, rather than (like our Sun) via radiation. This leads to lots of radiation bursts when convection cells reach the surface. At 1 A.U., no big deal. But, at an orbit close enough to keep - say - Earth as warm as it is orbiting the Sun, life would get hammered.
This isn't to say that *something* wouldn't evolve. It's just that at a basic level, it wouldn't resemble anything we're familiar with. And, given how long a red dwarf stays in the Main Sequence, there'd be billions upon trillions of years to simmer the soup 'til it was just right.
Luke, help me take this mask off
Uhh.. pardon me, who moderated this insightful?
All low-mass stars, including the Sun and ranging up to F-Type stars (about 1.7 times solar mass) have an outer convection zone (meaning that outside the core, and up to the surface, energy is transported by convection). There's nothing 'bursty' in that mechanism.
Hard radiation of low-mass stars is generated in the corona, which is heated by magnetic reconnection events (the magnetic equivalent of a short), leading to sudden release of the energy stored in magnetic fields. This is what is called 'stellar activity': starspots, flares, X-ray radiation, ...
Some red dwarfs are indeed much more active than the Sun, many are not. Activity is generally connected to the age of a star since magnetic fields are generated by a dynamo mechanism, and stars spin down slowly as they are aging, leading to a less efficient dynamo and a decrease of activity.