A group of American scientists has made a discovery that could be the answer to the great question of astronomy: are we alone in the universe?
Scientists at the University of California at Irvine have discovered that exoplanets have a zone around them that could harbor liquid water, a key ingredient for life.
Many exoplanets, planets outside of our solar system, are tidal lockwhich means that one side always faces the star they orbit and the other side is in permanent darkness.
But there is an area that all the planets have, which they have baptized as terminator zonewhich refers to the dividing line between the day side and the night side of the exoplanet.
Any existing water would likely freeze on the cold side of the exoplanet, but the warm side would be so hot that would evaporate.
The lead author of the study, published in The Astrophysical Journalis the doctor Ana Wolf, who said: “The dayside can be very hot, well beyond habitability, and the nightside is going to be freezing, potentially covered in ice.”
“We could have large glaciers on the night side. We want a planet that is at the point just the right temperature to have liquid water,” Lobo said.
The researchers wanted to find out if these exoplanets have the conditions to support life, such as the ability to hold water in its liquid form. If so, this would significantly increase the pool of planets that astronomers they could study for extraterrestrial life.
The researchers simulated the climate of various tidally locked exoplanets, observing their temperature variations, wind patterns and radiation exposure.
they used software which is normally used to model Earth’s climate, but they slowed down their rotation on their axis. This highlighted a ‘perfect’ zone around the terminator zone of these planets, whate could contain liquid waterallowing the existence of life.
“We’re trying to draw attention to more water-limited planets, which despite not having large oceans, might have lakes or other smaller bodies of liquid water, and these climates could actually be very promising.”added Dr. Lobo.
The researchers say they believe this is the first time astronomers have shown that there is a potential for life on exoplanets. Their finding may mean that scientists looking for signs of life on exoplanets will need to be aware that they may be hidden in specific areas.
“By exploring these exotic weather states, we increase our chances of finding and correctly identifying a habitable planet in the near future“, concluded Ana Lobo.