In a hotly anticipated press conference, a team of NASA Scientists revealed the discovery of 7 Earth-sized planets orbiting a nearby dwarf star. This is the first time so many planets have been found around a single star and a massive leap forward in the search for life elsewhere in the universe.
At a live press conference, Dr Michaël Gillon, University of Liège, and his team walked the watching world through their discoveries, which were made using NASA’s Spitzer space telescope and other large telescopes on the ground.
The newly reported planets orbit the Trappist-1 star, around 40 lightyears away. If we could travel at light speed, it would take us 40 years; in a jet plane, it would take us 44 million. The Trappist-1 star is smaller and cooler than our sun. The planets’ orbits of the star range from 1 and a half to 20 days, compared to the Earth’s 365 days. The worlds are so close to each other that you could stand one world and clearly see the others, just as we seen the moon.
One interesting difference from earth is that they are tidally locked- they have permanently dark and light sides, as opposed to the daily variation we see on our own planet
Of the seven new exoplanets, three of these, Trappist-1 e, f & g, occupy the star’s ‘habitable zone’- a distance where the temperature ranges are suitable for formation of water on a planet’s surface and where life is a possibility. The scientists have been able to calculate the size, mass and rough composition of most of planets, which are not dissimilar to Earth.
The Spitzer Space Telescope has been operational for 14 years and this its most exciting output to date. Further study on this system will inform future research on the formation of planets and how best to study the atmosphere of faraway worlds. The launching of more telescopes and the study of more dwarf stars like Trappist-1 will only improve the chances of finding habitable planets.
The James Webb space telescope, due to launch in 2018, will be NASA’s flagship telescope for space exploration and its first cycles will be used to look for other life possible life containing planets and study the Trappist system more closely. “The James Webb Space Telescope, will have the possibility to detect the signature of ozone if this molecule is present in the atmosphere of one of these planets,” explains Professor Brice-Olivier Demory, from the University of Bern in Switzerland, who was not present at the conference. “This could be an indicator for biological activity on the planet.”
The team stressed that a lot is still unknown and uncertain. However, Dr Zurbuchen was optimistic and suggested that as more telescopes are developed and technology improves, a lot of what is unknown can be answered: “Questions about are we alone are being answered as we speak.”