Photography: Bremer Sharp
Australian citizen scientists have helped to discover four new planets orbiting a star in the constellation Aquarius.
Trawling through data from the Kepler Space Telescope as part of the ‘Exoplanet Explorers’ citizen science project, participants discovered around 90 planets, including a system 597 light years away from Earth, where four ‘super earth’ sized planets are in close-orbit around a small star.
The planets are closer than Mercury is to our sun. In fact, they are so close that they take only between 3 and 13 days to fully orbit their star.
But because the star is smaller and cooler than our sun, some of the planets in the scaled-down solar system might lie within their star’s habitable zone. This means there is a small chance that life could exist in the system.
The planets have not yet been named, and are currently known as EE-1b, EE-1c, EE-1d, and EE-1e. The names of the volunteers whose work helped locate the system will feature on the paper reporting the discovery.
The Exoplanet Explorers project was one of two ANU citizen science projects launched through the ABC’s Stargazing Live program, filmed at the ANU’s Siding Spring Observatory.
Professor Brian Cox and co-presenter Julia Zemiro encouraged viewers to head online and help search for exoplanets or the mysterious ‘Planet 9’.
For many years a ninth planet, which is predicted to cause the lopsided orbit of a number of dwarf planets, has been believed to exist beyond Neptune. The search has recently been reinvigorated, and a team from the ANU’s Research School of Astronomy & Astrophysics (RSAA) are asking citizens to help their efforts analysing data from the university’s SkyMapper telescope.
Planet 9 is predicted to be between four and 10 times the size of Earth, and up to 350 times the distance between Earth and the sun. Scientists do not know if it would be a rocky or ice planet, but after the three days Stargazing Live was aired, they have determined that it must be smaller than Neptune.
A super-earth sized planet would be an exciting discovery, because super-earths are common in many systems, but it is difficult to study them when they are light years away. Comparatively close, if Planet 9 is found it could help astronomers better understand how planets are formed.
Woroni spoke to the head of the project, Dr Brad Tucker, and PhD student Ryan Ridden-Harper about their work in the Planet 9 search. Tucker described his surprise at volunteers’ enthusiastic responses over the three days Stargazing Live was aired.
‘We were ecstatic with the turnout,’ he said. ‘For the Planet 9 search we had 110,000 images, each checked 50 times, in under three days. If I sent Ryan to do his PhD project on it, it would’ve taken him an entire PhD, about four years, to do.’
As well as helping scientists deal with the sheer volume of data, volunteers are vital to the project because of their uniquely human brains. Although programs that can process the data are possible, humans can spot differences and identify patterns far better than any computer algorithm.
‘You would spend months to years writing something that could be foolproof and it still wouldn’t be as effective,’ Tucker explained. ‘With these kind of subtleties, human eyes are better.’
The work continues for the team at RSAA. Although Planet 9 has not yet been located, volunteers and scientists have identified at least four unknown bodies, on top of asteroids, known dwarf planets such as Chiron, and even a new star. The next step is to go back through the data, compare it with previously gathered information and determine whether these mysterious bodies are more asteroids, new dwarf planets, or even Planet 9 itself.
‘We will have a pretty good answer at the end of the year on whether we found this planet or it doesn’t exist, or if it’s in a very small parameter space of space and is going to be harder to find,’ Tucker predicted.
On top of this, the SkyMapper telescope is currently undertaking the first digital survey of the southern sky. The data will be made openly available, eliminating for some the arduous process astronomers must go through to gain research time on a telescope.
The hunt for Planet 9 is also ongoing, and anyone can get involved by visiting planet9search.org. There are many other citizen science projects to be found at zooniverse.org, from astronomy through to health science.
‘I always call astronomy the gateway drug of science,’ Tucker said. ‘People have a natural interest in astronomy and space, so by making it accessible, people realise there are all these other projects.’
The most exciting thing about citizen science projects for Tucker is that there’s always something new to discover. Ridden-Harper added his own take on the phenomenon.
‘All these thousands of people, who wouldn’t have otherwise spent their time perhaps even caring about astronomy, have come along put effort into a project, got interested in the scientific process and the process of astronomy, which is a very valuable thing to have if we want to bring people into science, and include them,’ he said.
Tucker agrees. ‘It benefits everyone, and that’s the beautiful thing about it. No one loses.’
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