Billions Of Life Bearing Planets? March 30, 2012Posted by Metabiological in Beyond Earth.
Tags: alien life, astronomy, planets in the milky way, red dwarfs, science
Could the universe be saturated with life? Is our galaxy filled with literally billions of worlds harboring that most precious of gifts, that strange and wonderful collection of matter and processes we call life? According to a new study by astronomers that may very well be the case.
A new result from ESO’s HARPS planet finder shows that rocky planets not much bigger than Earth are very common in the habitable zones around faint red stars. The international team estimates that there are tens of billions of such planets in the Milky Way galaxy alone, and probably about one hundred in the Sun’s immediate neighbourhood. This is the first direct measurement of the frequency of super-Earths around red dwarfs, which account for 80% of the stars in the Milky Way.
“Our new observations with HARPS mean that about 40% of all red dwarf stars have a super-Earth orbiting in the habitable zone where liquid water can exist on the surface of the planet,” says Xavier Bonfils (IPAG, Observatoire des Sciences de l’Univers de Grenoble, France), the leader of the team. “Because red dwarfs are so common — there are about 160 billion of them in the Milky Way — this leads us to the astonishing result that there are tens of billions of these planets in our galaxy alone.”
While this doesn’t prove anything conclusively it’s still very interesting for a few reasons. One, the novel approach of looking in a historically undervalued area (Red dwarf stars). Considering the sheer number of them that we apparently knew were out there it’s somewhat surprising it took someone this long to actually estimate the number of planets around them. Second is how conditions around Red Dwarfs differ from those we are used to around stars like are own. According to the researchers in addition to the obvious difference of being smaller and dimmer (thus allowing the Goldilocks zone to be closer to the planet) Red Dwarfs appear to lack large Jupiter sized worlds and are subject to stellar eruptions. Jupiter worlds may be important for protecting smaller rocky planets from life-destroying comets and meteors while solar flares are known to release potentially deadly radiation. Both of these factors could make the researcher’s estimates of life too generous.
But whatever. Putting practical considerations aside if true this is amazing news. The idea of a universe filled with life, variegated in all the forms evolution can dream up but connected by virtue of our shared status as reflections of Life itself, is the kind of idea that got me into the sciences in the first place. The kind of idea that fills me with a wonder and amazement at the unfathomable beauty of the cosmos. Sorry for waxing poetic there for a moment. I hope you’ll forgive a young man his optimism and bright-eyed enthusiasm.
P.S. Nobody mention the Fermi Paradox. I’m in too good a mood to worry about the Fermi Paradox.