The universe is an interesting mix of diverse creatures. There are giant, heavy black holes and giant galaxy clusters, and then there are the tiny, invisible quarks and electrons that make up most of matter. Objects like stars radiate energy while planets and moons depend on them to be worlds of their own – like planet Earth.
Even in our solar system, not all planets are created equal – the four planets closest to the sun, with iron and rock on their surfaces, are rocky while the other four are large gas giants with vortexes of gas and no solid surface.
Although Earth is the only planet of the eight that harbors life, rocky Earth-like planets are of great interest to scientists. They believe that if life exists anywhere else in the universe, it must exist on one of the ten billion rocky planets believed to exist.
It is estimated that half of the stars with temperatures similar to the Sun have rocky planets with liquid water on their surfaces, and more than 300 million are found in the Milky Way. Outside our solar system, scientists have discovered more than 5,000 exoplanets, of which 187 are potentially habitable, rocky, Earth-like planets. A major breakthrough occurred in 2017 when NASA astronomers discovered a planetary system around a star called TRAPPIST-1. This icy dwarf, much colder and redder than our Sun, lies 39 light-years away in the constellation Aquarius. It is named after NASA’s TRAPPIST (Transsiting Planets and PlanetesImals Small Telescope) telescope which assisted in the discovery.
TRAPPIST-1 has seven Earth-sized planets orbiting it, and scientists believe any of them could have liquid water on its surface. These planets, called TRAPPIST-1a via TRAPPIST-1g, are believed to be between 5.4 and 9.8 billion years old, or twice the age of our solar system. The planets are likely covered in tides and only one side of each planet is facing the star, creating a permanent day and night side to them. Using data from the telescope, the scientists concluded that TRAPPIST-1b and c are the warmest group because they receive the most light from stars, and TRAPPIST-1e, f and g tend to have water surfaces. Even though there’s no sign of life yet, TRAPPIST-1 could be a flashy new title as we explore to discover the world of a livable future!
–
