An Earth-like planet with an atmosphere, existing outside our solar system—new findings published in The Astronomical Journal is a step forward in the search for life beyond our world.
An atmosphere around an Earth-like planet outside our solar system is a big deal in the world of astronomy—an atmosphere could mean the existence of life. This is also the first time such a detection has been made; a tremendous step for the search for life in outer space.
The planet, dubbed a super-Earth, is named GJ 1132b. It orbits the star GJ 1132, and the system was viewed by the ESO/MPG telescope based in Chile by a team of researchers from Keele University led by Dr John Southworth. While life has not actually been found on the planet, Dr Southworth believes it is a “step in the right direction”.
Super-Earth GJ 1132b is a transiting planet, that is, its pathway is such that it passes directly between Earth and its host star—an event that happens every 1.6 days. It was viewed simultaneously at 7 different wavelengths at its transit during which a small of light from the star was blocked. The team measured the decrease in brightness that indicated the absorption of some of the star’s light by the planet and its atmosphere. The amount of light lost was, then, used to calculate the size of the planet. The results show that it is 1.4 times Earth’s size. Another finding from the new observations is that the planet appears to be bigger in one of the 7 wavelengths: this suggests that it is surrounded by an atmosphere opaque only to the particular light wavelength (it is not actually larger).
Dr Southworth and his team launched several simulations, trying to test possible atmosphere types for the planet. They found that those rich in water and/or methane might explain their findings. According to the researcher, GJ 1132b is much hotter than Earth; it could be a “water world” shrouded in a hot-steam atmosphere.
The study has a number of implications for the search of life in outer space, mainly because the star of the planet is a low-mass one, something very common in the universe. Normally, low-mass stars, which have lots of planets orbiting them, display high levels of X-rays and UV-light that should cause the evaporation of the atmospheres of planets. However, our super-Earth seems to have an atmosphere that can protect itself from this for centuries on end. If this is true, and given that low-mass stars are common, it could indicate that conditions conducive to life might be common elsewhere in the Universe.