An international study led by researchers at São Paulo State University (UNESP) in Brazil has identified a little-known but potentially significant threat: Asteroids that share Venus’s orbit and may completely escape current observational campaigns because of their position in the sky. These objects have not yet been observed, but they could strike Earth within a few thousand years. Their impacts could devastate large cities.

“Our study shows that there’s a population of potentially dangerous asteroids that we can’t detect with current telescopes. These objects orbit the sun, but aren’t part of the asteroid belt, located between Mars and Jupiter. Instead, they’re much closer, in resonance with Venus. But they’re so difficult to observe that they remain invisible, even though they may pose a real risk of collision with our planet in the distant future,” astronomer Valerio Carruba, a professor at the UNESP School of Engineering at the Guaratinguetá campus (FEG-UNESP) and first author of the study, told Agência FAPESP.

The study is published in the journal Astronomy & Astrophysics. The work combined analytical modeling and long-term numerical simulations to track the dynamics of these objects and assess their potential to come dangerously close to Earth.