Scientists of NASA announced discovery of an entire system of Earth-sized planets. In these seven planets, six innermost are rocky like earth.
Three of the planets lie in the star’s habitable zone. The habitable zone or goldilocks zone is the region surrounding a star in which liquid water could theoretically exist. This means that all three of these planets may have presence of water. This indication dramatically increased the possibility of life. This is the largest number of Earth-sized planets yet found which could support liquid water.
As per Scientists, the star in this system-TRAPPIST-1 is an “ultra cool dwarf”. The energy output from dwarf stars like TRAPPIST-1 is much weaker than that of our Sun. Planets would need to be in far closer orbits than we see in the Solar System if there is to be surface water. Fortunately, it seems that this kind of compact configuration is just what we see around TRAPPIST-1.”
Michael Gillon leads the TRAPPIST collaboration, which hunts for planets using two 60-centimetre telescopes of Chile and Morocco. Gillon said that the team initially reported three planets around the star, known as TRAPPIST-1, last May. Further research revealed that it was not a single planet but four that orbit Trappist-1 roughly every 4, 6, 9 and 12 days. Those four joined the two innermost planets, which whirl around the star once every 1.5 days and 2.4 days. The team also find a seventh, more distant planet.
The six inner planets probably formed farther away from their star and then migrated inward. Now, they are so close to each other that their gravitational fields interact that enabled the team to estimate each planet’s mass, which they range from around 0.4 to 1.4 times the mass of the Earth.
Distance from Our Earth
The system is just 40 light-years away. Although, it would take us millions of years to get there with today’s technology, but these findings are important milestone in search of life beyond Earth.
The Hubble Space Telescope is already being used to search for atmospheres around the planets. Emmanuel Jehin, a scientist who also worked on the research, asserts that “With the upcoming generation of telescopes, such as ESO’s European Extremely Large Telescope and the NASA/ESA/CSA James Webb Space Telescope, we will soon be able to search for water and perhaps even evidence of life on these worlds.”
This revelation is also important for researchers who are working to compare how worlds evolve. The TRAPPIST-1 system probably has a similar variety of worlds. “If one of these planets hosts life and the adjacent one doesn’t, why not?” asks Sarah Ballard, an astronomer at the Massachusetts Institute of Technology (MIT) in Cambridge.
Although at least some fraction of each planet could harbour liquid water, it doesn’t necessarily follow that they are habitable. TRAPPIST-1 emits about the same amount of X-ray and ultraviolet radiation as the Sun does, which would make it much more challenging for life to thrive.