We could be overlooking an entire population of asteroids that pose a threat to Earth on the very simple basis that they're extremely hard to see. In the space shared by the orbit of Venus, hundreds of undiscovered asteroids could be orbiting the Sun, hidden from our view simply because of their position. Co-orbitals don't orbit Venus itself, but loop around the Sun in sync with the planet's orbit – sometimes orbiting ahead, sometimes trailing behind, and sometimes crossing to and fro across Venus's path in complex patterns. An observatory in orbit around Venus, or sharing Venus's orbit, would be much better positioned to see the asteroids that share the planet's corner of the Solar System. "While surveys such as those from the Rubin Observatory might be able to detect some of these asteroids in the near future," the researchers write in their paper, "we believe that only a dedicated observational campaign from a space-based mission near Venus could potentially map and discover all the remaining 'invisible potentially hazardous asteroids among Venus' co-orbital asteroids."