The Gang of Five
Beyond the Mysterious Beyond => The Fridge => Topic started by: rhombus on October 10, 2013, 12:12:21 PM
-
Astronomers at the Pan-STARRS 1 wide-field survey telescope have confirmed the discovery of a rogue planet about 80 light-years from Earth. A rogue planet is a planet that is freely floating in interstellar space and not in orbit around any star. Similar free-floating planets have been found before, but it was unclear whether they were brown dwarfs or actual planets.
http://www.nbcnews.com/science/astronomers...-sun-8C11366309 (http://www.nbcnews.com/science/astronomers-say-theyve-spotted-lonesome-planet-without-sun-8C11366309)
-
So it's still quite warm. It must have left its star system recently, in the last several million years.
-
http://www.cam.ac.uk/research/news/watery-...able-exoplanets (http://www.cam.ac.uk/research/news/watery-asteroid-in-dying-star-points-to-habitable-exoplanets)
Basically a weird overabundance of oxygen has been discovered in the atmopshere of a white dwarf 150 light years away. And since the white dwarf doesn't contain any significant amounts of carbon, the excess oxygen can't be the result of nuclear fusion or comet impact, which means it must come from a rocky planet or water-rich asteroid. By analizing the amount of silicon, aluminium and other elements it was ascertained that there is still too much oxygen to have come from a rocky planet being torn by the star's gravity, so the only explanation left is that it must have come from large Ceres-like asteroid, with more than 20% of its mass being water, that was shredded by the star's gravity.
Furthermore, in order for an asteroid of such size (90 km or more) to come so close to the white dwarf, it must have been pushed by a giant planet.
So, essentially we have a system with large water-rich asteroids in the vicinity of planets, an arrangement which ensured the bombardment of Earth, providing it with abundant water during the first half of a billion years of its existence.
It is quite possible that water-rich rocky planets are present in the system, however they must be frozen because the white dwarf has a minuscule energy output.
-
This is very interesting news and discovery. Water asteroids & on planets could be more common then folks at first thought. I'm sure they are all frozen most likely.
-
It is quite possible that water-rich rocky planets are present in the system, however they must be frozen because the white dwarf has a minuscule energy output.
Probably, but I don't think that we can completely dismiss the possibility of smaller bodies being heated by tidal flexing in the same manner that Europa is heated by the tidal influence of Jupiter.
In either case, as you said, the findings of the research you cited does provide direct evidence for the same arrangement that is believed to have eventually led to habitable conditions on Earth. It is amazing how our place in the Universe seems less unique with each new scientific discovery concerning exoplanets. Some people may find that to be disheartening, but I find it to be quite the opposite. Rather, I would find it to be disheartening if we were in fact unique and the conditions for life did not exist elsewhere.