Life on Trappist-1: Two planets of distant star system may have water and Earth-like temperatures

As scientists across the world continue to hunt for signs of life beyond Earth, a group of researchers have found that two of the seven Earth-sized rocky planets orbiting a distant Red dwarf, dubbed Trappist-1, may have the necessary conditions to support life with appropriate surface temperatures and water.

Located some 40 light years away in constellation Aquarius, the Trappist-1 system is too far to be explored in person. However, since its discovery, researchers have created a plethora of models to study the factors that could help them determine if any of those seven planets are habitable.

Three planets of the system, Trappist-1e, 1f and 1g, are believed to be in the habitable zone, just at the right distance from their star.

But, Amy Barr, senior scientist at the Planetary Science Institute, and her colleagues suggested that Trappist-1d and 1e planets could be most potential to support life, the Guardian reported.

Barr and her team prepared mathematical models of the planetary system and found that six of the seven planets could have water, either in liquid or icy state.

Further studies of the orbit around the red dwarf revealed that 1d and 1e have modest amount of tidal heating, which could be contributing towards maintaining reasonable surface temperatures. These "planets also orbit very close to the star, with orbital periods of a few days," Barr explained in a Phys.org report. "Because their orbits are eccentric – not quite circular – these planets could experience tidal heating just like the moons of Jupiter and Saturn." The weird egg-shaped orbit stretches and squeezes the planets, creating the internal heat.

The effect of tidal heat, however, varies from planet to planet. Trappist-1b and 1c experience enough tidal heating to maintain magma oceans in their rock mantles. 1c, which may have a solid rock surface, could also have silicate magmas eruptions, something akin to Jupiter's moon Lo, the researchers found.

In contrast, 1d and 1e could experience less tidal heat, which could ultimately make surface temperatures reasonable enough to host life,acccording to the report. The research team believes that planet 1d could have temperatures around 15C while 1e could be much cooler, with temperature similar to what we see in Antarctica.

The findings, set to be published in journal Astronomy & Astrophysics, show promise but further studies will have to be conducted to determine if conditions for life actually exist in the alien world. The group will run more sophisticated models to understand the geodynamics of ice-rich planets 1f, 1g, and 1h.

Just a few weeks back, another team of astronomers had posited that the distant bodies in the Trappist-1 system may have the capability to hold on to their atmosphere, another necessary condition for making a planet habitable.