An international team of scientists has discovered that Venus’s orbit may conceal asteroids that pose a potential threat to Earth. The study, published on the preprint platform arXiv, revealed that among the 20 known asteroids crossing Venus’s orbit, some may be over 140 meters in diameter and capable of approaching our planet at a dangerous distance.
Why Are These Asteroids Hard to Detect?
According to the study’s lead author, Valerio Carruba from the University of São Paulo, these asteroids are difficult to observe due to their position relative to the Sun. Their brightness is overwhelmed by sunlight, rendering them nearly invisible to telescopes most of the time. Astronomers can only detect these objects during brief moments when they move away from the Sun, but even then, observations are challenging due to their low brightness and rapid motion.
Chaotic Orbits and Risks
Simulations showed that the orbits of these asteroids are highly unstable. Within 150 years, their trajectories become unpredictable due to gravitational perturbations from Venus, Earth, and other planets. Some of these objects could come within 7.5 million kilometers of Earth, classifying them as Potentially Hazardous Asteroids (PHAs) under NASA’s criteria.
Asteroids larger than 140 meters could cause catastrophic consequences if they collide with Earth. For example, a 150-meter object could trigger an explosion with hundreds of megatons of energy, thousands of times more powerful than the atomic bombs dropped in 1945. Such an impact could devastate entire regions, cause widespread fires, and lead to global climate changes.
Connection to Venus
As Earth’s closest planetary neighbor, Venus plays a key role in the dynamics of these asteroids. Its orbital resonance with certain objects, such as the quasi-satellite 2002 VE68, keeps them near the planet for millennia. However, gravitational influences from Venus and other planets, including Jupiter, can dislodge asteroids from stable orbits, potentially sending them toward Earth.
Researchers note that 2,809 objects crossing Venus’s orbit are already known, including 98 external “grazers.” One such asteroid, 524522 Zoozve, also crosses the orbits of Mercury and Earth, but its connection to Venus is temporary and will end in about 500 years.
Solutions for Earth’s Protection
Scientists propose two approaches to study and mitigate the threat:
Ground-based Observations. The Vera Rubin Observatory in Chile, set to begin operations in 2025, will be able to detect faint asteroids due to its high sensitivity, enabling a more comprehensive catalog of potentially hazardous objects.
Space Missions. Sending a probe to Venus to directly study its neighboring asteroids would allow precise determination of their composition, sizes, and orbits. Missions like Russia’s planned Venera-D or Europe’s EnVision could include observations of near-Venus asteroids.
Additionally, NASA and other agencies are developing asteroid deflection methods, including gravitational maneuvers and kinetic impacts, as demonstrated by the DART mission. A gravitational maneuver using Venus or Mars could alter an asteroid’s trajectory to prevent a collision with Earth.
Significance of the Study
The discovery highlights the importance of monitoring not only near-Earth asteroids but also those associated with the orbits of neighboring planets. Despite its proximity, Venus remains understudied in the context of asteroid threats. According to NASA, about 44% of asteroids larger than 140 meters remain undetected, making such research critically important.
These asteroids are a hidden threat we’re only beginning to understand. Studying them requires new technologies and international cooperation, noted Carruba.