SETI has announced that they will begin looking for possible alien life in a strange place that originally was thought to be a poor location for life – around red dwarf stars.
Here is the press release from SETI:
“Red dwarfs – the dim bulbs of the cosmos – have received scant attention by SETI scientists in the past,” notes Institute engineer Jon Richards. “That’s because researchers made the seemingly reasonable assumption that other intelligent species would be on planets orbiting stars similar to the Sun.”
This conservative assessment was bolstered by the argument that few planets were likely to be found in the habitable zone of a red dwarf star, simply because that zone is far narrower than for brighter stars like the Sun. Additionally, any worlds that were in this zone would be orbiting so close to their suns that they would quickly become tidally locked – with one hemisphere perpetually facing the star. It was assumed that this would produce a planet that was intolerably hot on one side, and brutally cold on the other, ruling it out as an abode for life.
However, more recent research has indicated that, if these worlds have oceans and atmospheres, heat would be transported from the lit side to the dark, and a significant fraction of the planet would be habitable. In addition, exoplanet data have suggested that somewhere between one sixth and one half of red dwarf stars have planets in their habitable zones, a percentage comparable to, and possibly greater, than for Sun-like stars.
“Significantly, three-fourths of all stars are red dwarfs,” notes SETI Institute astronomer Seth Shostak. “That means that if you observe a finite set of them – say the nearest twenty thousand – then on average they will be at only half the distance of the nearest twenty thousand Sun-like stars.”
Closer stars mean that any signals would be stronger.
Also, red dwarfs burn for a period of time that’s greater than the current age of the universe: every red dwarf ever born is still shining today. They are, on average, billions of years older than stars than Sun-like stars.