A huddle of seven worlds similar in size to Earth, has been discovered around a small, faint star in the constellation of Aquarius, 40 light-years away, Nasa have announced. Three of the planets are in the ‘habitable zone’ of the star, which is the region around a star in which a planet could be kept warm enough to allow liquid water to exist on its surface, and the discovery has been described by some as a 'Holy Grail' for science.
The planets were first noticed while passing in front of their parents star, Trappist-1, which periodically dimmed noticeably, suggesting that planets were blocking some of the light. From the shape of these blackouts, astronomers could calculate the size of the planets, and initially thought there were at least three planets, before eventually concluding there were seven. It's the largest number of Earth-sized planets ever found.
The star itself, Trappist-1, is small. At the NASA news conference, Dr. Gillon said, if our sun were the size of a basketball, Trappist-1 would be a golf ball. But although the light from the star is much weaker than the light from our sun, the planets are close enough to it that they can avail of its light and heat. As such, scientists at the NASA announcement went as far as to say that ‘The discovery gives us a hint that finding a second earth is not just a matter of if but when.’
If this discovery raises exciting questions, the time scale in which they could be answered is equally exciting. Scientists hope to know whether there is life on the planets within a decade. Likewise, further discoveries will be expected. Ignas Snellen, an astrophysicist at the Leiden Observatory in the Netherlands, has claimed the findings show that Earth-like planets must be extremely common. Cool red dwarfs are the most common type of star, so astronomers are likely to find more planetary systems like that around Trappist-1 in the coming years.
Are we alone out there? We’re making a step forward with this — a leap forward, in fact — towards answering that question.
'You can just imagine how many worlds are out there that have a shot to becoming a habitable ecosystem,' Thomas Zurbuchen, associate administrator of NASA’s science mission directorate, said during a NASA news conference on Wednesday. 'Are we alone out there? We’re making a step forward with this — a leap forward, in fact — towards answering that question.'
scientists will insist that this breakthrough increases the chances of even more exciting, harder to ignore breakthroughs in the not too distant future.
The furthermost discoveries that could come from this will be exciting scientists and enthusiasts alike, as there is a possibility that any, or all of the planets could in theory host life. But the more mundane things that should come as almost a guarantee are also prevalent in their own right. This star is young when compared to our own sun, and although the sun is expected to go out in a few billion years, Trappust-1 is expected to shine on for 700 times longer than the universe has currently existed for. As such, since we don’t know exactly why the earth is able to host life, even if these newly discovered planets don’t host water or life now, it doesn’t mean they don't have the potential to do so one day. This in itself could prove a useful research tool, offering scientists an unprecedented laboratory in which to study planetary habitability, which may result in scientists finding factual answers to things which could previously only be speculated on.
Reactions to this from those outside the scientific community will be varied. Some will be waiting excitedly for any and all follow up discoveries that come in the next few years; others will scoff and sceptically question those who expect any sign of life to come from the news. The majority will probably soon forget about it, and wait for bigger, more significant breakthrough to arrive before they really take any notice. But even for the sceptics amongst us who will let this news pass by, scientists will insist that this breakthrough in itself is significant, and that it increases the chances of even more exciting, harder to ignore breakthroughs in the not too distant future.