ESO / M. Kornmesser
Our first view of a rock from beyond our solar system was fleeting. Astronomers spotted the object, later called ‘Oumuamua, in October 2017, and it was quickly too distant for Earth-based telescopes to spot.
In late November 2017, researchers pointed the Spitzer Space Telescope towards where ‘Oumuamua should have been and stared for more than 30 hours. It saw nothing.
Immediately, the researchers wondered whether that was because of ‘Oumuamua’s strange acceleration – astronomers using the Hubble Space Telescope had found that it …