Twenty years of hunting exoplanets has given us nearly 2000 chunks of non-fusing rock and gas. It’s also given us the statistics to show that the galaxy is likely to be filled to the brim with other worlds, giving incredible potential for finding other Earths and maybe even other life. The latest discoveries involve the use of better technology, more intuitive methods, and more comprehensive searches. This means that we aren’t just discovering planets that are further from Earth, we are finding the ones that are nearby, but small enough to have been hidden, until now.
The red dwarf star Wolf 1061 is only 14 light years away from Earth. It’s not easily visible in the night sky due to it’s small size and low brightness. But this common red dwarf hosts three small, rocky planets, each one orbiting close to the star, and one that lies within the habitable zone – the closest such planet ever discovered.
The three planets orbit in 5, 18, and 67 days, and have respective masses of 1.4, 4.3, and 5.2 times that of Earth. “Our team has developed a new technique that improves the analysis of the data from this precise, purpose-built, planet-hunting instrument, and we have studied more than a decade’s worth of observations of Wolf 1061,” says Professor Chris Tinney, head of the Exoplanetary Science at UNSW group.
The habitable zone of a star is the range of distances from a star where liquid water could survive. Often called the goldilocks zone, the ‘just right’ spot is close enough that water is warmed by the star without being close enough to burn up, and not too far to freeze.
As our technology improves, we will continually revisit stars that have already been found to develop planets. More planets that are too small to see are likely to be lurking in the shadows, and their discovery will reveal the secrets of planetary formation that can be applied across the universe.