Is danger lurking near Venus? Asteroids are orbiting our neighboring planet. According to a new study, these could pose a threat to Earth.
The team led by Valerio Carruba from the University of São Paulo is currently aware of 20 co-orbital asteroids on Venus. The study with the meaningful title “The invisible threat: assessing the collisional hazard posed by the undiscovered Venus co-orbital asteroids” was submitted to the journal Astronomy and Astrophysics and is available as a preprint on the document server Arxiv. “Our goal is to assess the potential threat to Earth from the as yet undiscovered Venusian coorbitors and to investigate their detectability from Earth and by space observatories.”
A Venus asteroid is considered potentially hazardous asteroid (PHA) if it has a diameter of at least 140 meters and is less than 0.05 astronomical units (AU) – which is just under 7.5 million kilometers – from Earth's orbit. The problem with the Venus asteroids, according to the researchers, is that they are “highly chaotic”, “with Lyapunov times on the order of 150 years”. This means that their orbit becomes unpredictable after this time due to the chaotic dynamics.
36,000 years simulated
The team created a system with different orbital inclinations and placed 26 asteroids with different orbital properties in these grids. They then used this system to simulate 36,000 years in our solar system regarding whether one of the asteroids would come close to Earth.
According to this, the Venus asteroids may well pose a danger to the Earth. The issue, however, is that it is difficult to detect and observe them: Venus orbits the sun on an orbit within the Earth. They must therefore be observed against the sun.
The team investigated whether the Vera Rubin Observatory, which will be put into operation this year, could be used for this purpose. However, due to the glare from the sun, this would only be possible periodically. Observation windows are usually closed when the objects are closest to the Earth.
The team therefore suggests observing Venus up close. “We believe that only a special observation campaign by space mission in the vicinity of Venus could potentially map and discover all still 'invisible' PHAs among the co-orbital asteroids of Venus.”
Werner Pluta