Scientists have used artificial intelligence (AI) to uncover two more hidden planets in the data collected by the Kepler space telescope.
The technique shows promise for identifying many additional planets that traditional methods could not catch.
Researchers from The University of Texas at Austin in the US created an algorithm that sifts through the data taken by Kepler to ferret out signals that were missed by traditional planet-hunting methods.
The process, described in the The Astronomical Journal, should help astronomers find many more missed planets hiding in Kepler data.
"K2 data is more challenging to work with because the spacecraft is moving around all the time," said Andrew Vanderburg, from UT Austin.
This change came about after a mechanical failure. While mission planners found a workaround, the spacecraft was left with a wobble that AI had to take into account.
The Kepler and K2 missions have already discovered thousands of planets around other stars, with an equal number of candidates awaiting confirmation.
The two planets are both very typical of planets found in K2, researchers said.
"They're really close in to their host star, they have short orbital periods, and they're hot. They are slightly larger than Earth," said Anne Dattilo, who led the study.
Of the two planets, one is called K2-293b and orbits a star 1,300 light-years away in the constellation Aquarius. The other, K2-294b, orbits a star 1,230 light-years away, also located in Aquarius.
Once the team used their algorithm to find these planets, they followed up by studying the host stars using ground-based telescopes to confirm that the planets are real.
These observations were done with the 1.5-metre telescope at the Smithsonian Institution's Whipple Observatory in Arizona and the Gillett Telescope at Gemini Observatory in Hawaii.
The future of the AI concept for finding planets hidden in data sets looks bright. The current algorithm can be used to probe the entire K2 data set, Dattilo said -- approximately 300,000 stars.
The method couls also be applied to Kepler's successor planet-hunting mission, TESS, which launched in April 2018. Kepler's mission ended later that year.