A close up of Venus in the darkness of space. A hidden population of asteroids sharing Venus' orbit could threaten Earth in a few thousand years, and we might not even see them coming without better telescopes. Unlike asteroids in the main belt between Mars and Jupiter, these objects orbit the sun near Venus in a one-to-one resonance, completing one solar circuit in the same time as Venus. One orbit could see an asteroid keeping fairly close to Venus, while later orbits could put it dangerously close to Earth's, possibly every few thousand years or so. "During these transition phases, the asteroids can reach extremely small distances from Earth’s orbit, potentially crossing it," Carruba says.