NASA’S SPITZER SPACE TELESCOPE

has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.

The system was first observed by the southernmost of a pair of telescopes. The Transiting Planets and Planetesimals Small Telescope – or TRAPPIST-SOUTH – in Chile during 2016 and at the time only three planets were revealed. It was also confirmed two of the planets have orbital periods of 1,5 and 2,4 days respectively, while the third’s orbital period proved more difficult to determine and was estimated at between 4,5 and 73 days.

Follow-up observations with NASA’S Spitzer Space Telescope and supporting ESO ground-based telescopes revealed four more planets in the system and confirmed they were all close to Earth’s size.

Further research revealed three of the planets were located in the area around the parent star where a rocky planet will most likely have liquid water. This area is also known as the habitable zone.

“This discovery could be a significant piece in the puzzle of finding habitable environments; places that are conducive to life,” said the associate administrator of NASA’S Science Mission Directorate, Thomas Zurbuchen. “Answering the question ‘are we alone?’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step towards that goal.”

It has also been confirmed the orbit of TRAPPIST-1’S seven planets would fit into the space between our Sun and Mars (pictured above). What does this mean? As depicted in the image on this page, if you were to stand on the surface of one of the planets, you’ll be able to see the other planets in the sky and possibly even identify their geological features.