July 8, 2014
Would-Be Life Supporting Planet Doesn’t Actually Exist
I think everyone has at least wondered if we’re alone in the Universe. Whether you believe that this old rock is the only one with life on it or not, it’s impossible to deny the vastness of space and the awe that comes with the complexity of our space programs. Like most kids my age, I was fascinated with science fiction, Heck, I bet every kid has imagined flying through space at warp speed, perhaps meeting extra-terrestrial life (or blowing up giant moon-sized battle stations). For a brief while, scientists thought they had found a planet potentially capable of sustaining life, but unfortunately for those of us with wild imaginations chock full of aliens, it was destined not to be so. Even if we were able to develop the technology to travel that far, and even if we did bring with us a sustainable genetic sample … we’d end up floating blankly in space, looking for a planet that’s actually not there. Gliese 581g was one of two planets that, according to a new study released by Penn State, don’t actually exist. They’re nothing more than figments of our collective imagination, compiled by a cluster of misinterpreted solar activity data.
It started back in 2010 with the discovery of Gliese 581; an M dwarf star located roughly 22-light years away, nestled comfortably within the constellation Libra. After its initial discovery, we began investigating the solar phenomena surrounding the star, hoping to find out more about it. Further discovery revealed the likely existence of six-planets, one of which — Gliese 581g — was an Earth-like planet that happens to be smack dab in the middle of Gliese 581’s Goldilocks Zone, which is a colloquial term for “circumstellar habitable zone. Basically, the planets orbiting in this sweet spot have enough atmospheric pressure to hold water on their surface. Seeing as how we’re made up of, oh, about 70% water, that’s a pretty important prerequisite for life.
The calculations placed Gliese 581g at between 3.1 – 4.3x the mass of earth, with an atmosphere that supposedly had the potential to support long-term life, similar to our own. Unfortunately, the calculations that suggested the presence of 581g were based on the presence of another planet, 581d. As it turns out, the most recent study was able to retroactively calculate several questionable variables using the actual measurement of Gilese 581’s rotation speed. With those recalculations, the team was able to use spectrography data to investigate the lines of sodium and hydrogen-alpha absorption — key factors in determining the star’s rotation. When they plugged in the data to clear up the noise in the signals, they stumbled across the awkward discovery that 581d’s presence was more than likely a false positive caused by intermittent solar activity on the part of Gilese 581.
The entire premise of 581g had been predicated on the existence of 581d, and with the first out of the picture, the likelihood of the second ever existing dropped to near zero.
Sorry, space cowboys. Looks like you’ll have to keep on looking.
Image Credit: Thinkstock