Earth-like planets have been discovered, which increases the chance of spotting a new world that can support life. 40 light years away, experts observed seven Earth-sized terrestrial planets orbiting a dwarf star.
“The seven planets are temperate. This means that they could have some liquid water and maybe, by extension, life on the surface,” said lead author Michaël Gillon in statement.
The TRAPPIST-1 star has seven Earth-size planets orbiting it. (c) NASA/JPL-Caltech
The researchers observed the planets orbiting the star, TRAPPIST-1. They were able to identify its size and orbit because of the shadow they cast as they pass in front of the star.
After a continuous observation from NASA’s Spitzer Space Telescope, the experts have now witnessed 34 clear transits and attributed them to seven different planets. Their next step is to determine the planet's composition of atmospheres.
According to experts, the planets seem to be tidally locked. Meaning, one side always faces the star, and the other is always dark.
However, the researchers believe the atmosphere of these planets may support life, which consist of methane, oxygen, and carbon dioxide in the right relative concentrations.
“There is one combination of molecules, with some relative abundances, that would tell us there is life with 99 percent confidence,” said Gillon. “Oxygen itself is not enough.”
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Thanks to today's technology, the researchers would be able to identify further details about this mystifying world if they can support life.
“With current facilities (the Hubble and Spitzer telescopes), we can obtain the very first insights into the atmospheres of these planets, find out if they have a large and clear atmosphere, and possibly detect molecules such as water and methane,” co-author Julien de Witt told Research Gate.
“Once the James Webb Space Telescope (JWST) launches in 2018, we will be able to go one step further in our research. Assuming the planets have an atmosphere, JWST will provide us with more detailed information about their composition, temperature, and pressure. This will help us assess their habitability within five to ten years.”
Based on the planet's proximity to the star, the sides of the planets facing the star seem dimly lit like a sunset on Earth.
"The spectacle would be beautiful, because every now and then, you would see another planet about twice as big as the moon in the sky,” said co-author Amaury Triaud.