Scientists have identified two exoplanets just 39 light years from us as potentially Earth-like following an important study by scientists at MIT. Researchers made a historic first atmospheric observation of an Earth-size planet to identify the exoplanets as being rocky, and therefore potentially habitable.
The exoplanets orbit a star called Trappist-1. It is a cold, dim red star found about 39 light years away from Earth in the constellation of Aquarius. The ultracool dwarf star is believed to be not much larger in diameter than Jupiter and is roughly 2000 times dimmer than the Sun. These types of stars make up roughly 15% of all stars in the vicinity of the Sun, and scientists believe this type of star could be the place to look for extra-terrestrial life.
Using data gathered from Hubble, researchers at MIT were able to make the first atmospheric observation of an Earth-sized planet outside of our Solar System. The observations determined that both planets lacked the atmospheric qualities to be considered a gas dwarf (effectively a mini-Jupiter), and therefore could be inferred as rocky in nature.
Although we know that these planets are rocky, the density of their atmosphere remains unknown. This information is paramount for the question of habitability to be answered, since a rocky planet like Mercury with a very thin atmosphere is clearly not habitable. However, this data may take a little while to collect. It is expected scientists will have to wait until the James Webb Space Telescope is in operation, which is still a couple of years away. With the use of the revolutionary telescope, scientists will be able to characterise the atmospheres of Earth-like planets in extraordinary, unprecedented detail.
A recent study released by scientists on NASA’s Dawn mission has uncovered new details about the mysterious bright spots on Ceres. Since the Dawn spacecraft arrived at the dwarf planet in March 2015, the scientific community has been enthralled in the mystery surrounding the bright spots discovered by the probe.
The most interesting of the 130 bright spots discovered was within the Occator Crater, a 90-kilometre wide crater that is believed to be just 80 million years old. The bright, reflective patches found at the bottom of the crater have intrigued scientists ever since Dawn first entered orbit. According to the study, the crater’s dominant mineral is sodium carbonate. This would suggest hydrothermal activity exists within Ceres, since the material is usually found in hydrothermal environments here on Earth. The results also suggest that liquid water may have been present beneath the dwarf planet’s surface in the recent past or perhaps a body of water that has since frozen over.
"The minerals we have found at the Occator central bright area require alteration by water," De Sanctis said. "Carbonates support the idea that Ceres had interior hydrothermal activity, which pushed these materials to the surface within Occator."
This is not the first time sodium carbonate has been found in space. The compounds have previously been found on Saturn’s moon Enceladus, within the plumes of material that are ejected from the icy moon’s surface.
Launched in September 2007, Dawn first encountered the asteroid Vesta in 2011. Following fourteen months of intense data collection, the probe fired its ion thrusters and set off for dwarf planet Ceres. The probe entered orbit around Ceres in March of last year and has since sent back valuable data giving scientists on Earth clues as to its history in the Solar System. The Dawn spacecraft is expected to continue orbiting Ceres for several years to come. There is potential that the probe may be sent to a third and final asteroid on its tour of the Solar System, but these plans have yet to have been confirmed.