The research was carried out using NASA’s Kepler Space Telescope, which captured intriguing signals suggesting Earth-sized planets were hiding in space.
These signals, however, were not counterbalanced by a longer signal that one would expect if they were joined by a host star, such as our Sun.
The researchers therefore suggest that stars would once have formed around their own star, before being ejected from their solar system by the gravitational effect of other, heavier neighbors.
The signals were captured using the “microlens” principle, which was first predicted by Albert Einstein. This happens when the stars in the foreground can act as magnifying glasses for the stars behind them, which can be seen as bursts of brightness.
Most of these rare incidents are caused by stars. But a small number of this very small number of incidents are caused by planets.
It was signals that appeared to be caused by other worlds that were captured by scientists in the new study – despite fears they may never be found.
“These signals are extremely difficult to find,” said Iain McDonald of the University of Manchester, who led the research.
“From this cacophony, we’re trying to extract tiny, characteristic illuminations caused by the planets, and we only have one chance to see a signal before it disappears. It’s about as easy as searching for a firefly’s single wink in the middle of a freeway, using just a cell phone.
The Kepler Space Telescope was never designed for this kind of work. Its main job is to research other planets by watching for the shadows they cast as they pass in front of their stars.
“Kepler has done what it was never designed to do, providing new provisional evidence for the existence of a population of land mass floating planets,” said Eamonn Kerins, also of the University of Manchester. , who was a co-author on the study.
“Now he is relaying to other missions that will be designed to find such signals, signals so elusive that Einstein himself thought they were unlikely to ever be observed.” I am very pleased that ESA’s next Euclid mission can also join this effort as an additional scientific activity to its core mission. »
These missions – and other research from NASA and various space agencies – will seek to confirm the existence of these floating planets and what they might look like.
An article detailing the results is published in the Monthly notices from the Royal Astronomical Society.