Our image of extraterrestrial life is closely connected to that of water-based life forms. Scientists are looking through telescopes at various parts of the Universe in an attempt to find planets similar to Earth. The hope is that an Earth-like planet will support similar life forms. Water is the most important element needed for such a scenario, so researchers search various characteristics that will convey the substance’s presence. Apparently, companion planets extend chances to find life on exoplanets.
Scientists from University of Washington and University of Arizona reached a conclusion which will offer help in the quest for planets with water outside of our solar system. One important fact is that water stays in liquid form only in a certain temperature range. Usually what happens is that after a planet passes a certain age, it gets colder and loses its ability to potentially sustain life. This means that the chances to identify an Earth-like planet decreases because a colder planet cannot sustain life. Until we have access to instruments allowing us to see further in space, researchers have to base their findings on characteristics presently visible.
Until life will be spotted on exoplanets, NASA plans on sending another mission to Europe, Jupiter’s satellite, to examine its icy crust and answer the question if liquid water lies underneath.
Companion planets extend chances of finding life because they keep each other warm
Barnes, Van Laerhovan and Greenberg discovered that planets with companion planets might have greater chances of hosting life, because they maintain their heat longer. The companion planet exerts gravitational push and pull forces. As a consequence, a tidal heating occurs, preventing the planet from getting cold.
By running a computer model, researchers found that planets roughly the size of Earth running in noncircular orbits around small stars have the potential to display tidal heating if a companion planet is around. The role of the companion planet is to keep the orbit noncircular.
“When the planet is closer to the star, the gravitational field is stronger and the planet is deformed into an American football shape. When farther from the star, the field is weaker and the planet relaxes into a more spherical shape,” Barnes said. “This constant flexing causes layers inside the planet to rub against each other, producing frictional heating.”
The discovery increases the chances of finding habitable exoplanets, as this type of duo is easier to spot through telescopes. Companion planets extend chances of finding life, which might be very evolved, as the planets are warm for longer periods.
