Undetected, Dangerous Asteroids Could Be Lurking in Venus’s Orbit

Space can be a dangerous place, with massive rocks hurling through the solar system at fast speeds, some of which may be headed in our direction. NASA and other agencies keep a close watch on the skies, on the lookout for potentially hazardous asteroids that threaten Earth. As it turns out, however, a unique group of potentially problematic asteroids may be hiding in plain sight.

A group of researchers are warning of the potential threat of asteroids that share the orbit of Venus, circling the Sun at a close distance to Earth—but they’re practically invisible to our current observational tactics. In a recent study published in the Astronomy & Astrophysics journal, scientists reveal a population of potentially dangerous asteroids, which would appear in telescopic observations around two weeks before a potential impact on Earth.

Rocky companions

There are currently 20 known asteroids that co-orbit with Venus, although astronomers suspect there are many more space rocks in similar orbits, but they’re hard to detect because of the Sun’s glare. These asteroids may have originated in the main asteroid belt between Mars and Jupiter and were later scattered toward the inner solar system by bumping into the planets.

The co-orbital asteroids of Venus do not orbit the planet itself but rather follow a similar orbital path around the Sun. Although their close proximity to Venus prevents them from colliding with our neighboring planet, Earth is not safe from their potential threat.

The team of researchers behind the new study set out to assess the possible threat posed by the undetected population of Venus’ co-orbital asteroids. They combined analytical models of the motion of the asteroids with numerical simulations to monitor potential close encounters with Earth. The results revealed risky regions where the population of asteroids comes within an eerily close distance to Earth, coming within less than 0.0005 astronomical units (75,000 km, 46,000 miles) of our planet’s orbit. That close distance allows for a potential collision with Earth, which would result in wide-scale devastation on our planet.

“Our study shows that there’s a population of potentially dangerous asteroids that we can’t detect with current telescopes,†Valerio Carruba, a professor at the UNESP School of Engineering at the Guaratinguetá campus (FEG-UNESP) and lead author of the study, told Agência FAPESP. “Asteroids about 300 meters [984 feet] in diameter, which could form craters 3 to 4.5 kilometers [1.9 to 2.8 miles] wide and release energy equivalent to hundreds of megatons, may be hidden in this population.â€

The study also analyzed the potential of detecting the group of asteroids using recently inaugurated observatories such as the Vera C. Rubin Observatory. “Such asteroids can remain invisible for months or years and appear for only a few days under very specific conditions. This makes them effectively undetectable with Vera Rubin’s regular programs,†Carruba added. “Planetary defense needs to consider not only what we can see, but also what we can’t yet see.â€