While a potential “city-killer” asteroid identified last year might not be on a collision course for Earth, new research indicates it isn’t necessarily the only asteroid with significant destructive power that we should be concerned about.
Recently, researchers from São Paulo State University in Brazil found that several co-orbital asteroids of the planet Venus pose collision hazards for Earth. Altogether, 20 of these asteroids are known to scientists.
Authors of the study assessed risk of collision based on the orbital eccentricity of the asteroids. Orbital eccentricity refers to the shape of the orbit and how much it deviates from a perfect circle.
“There is a range of orbits with [eccentricity larger than] 0.38, larger at lower inclinations, for which Venus’ co-orbitals can pose a collisional hazard to Earth,” said the study, published this month in the Astronomy & Astrophysics journal.
To study the risks these Venusian co-orbitals, pose to our planet, the researchers used “semi-analytical models of the 1:1 mean-motion resonance with Venus and numerical simulations to monitor close encounters with Earth on several co-orbital cycles,” the study explained. This work included analyzing “observability windows and brightness variations for potential Venus co-orbitals as viewed from ground-based telescopes to assess their future detection feasibility with next-generation survey capabilities.”
Observations from the Rubin Observatory in Chile were used to complete the research.
According to the Daily Mail, three of the Venus orbit asteroids – 2020 SB, 524522, and 2020 CL1 – “have orbits that take these asteroids dangerously close to Earth.”
“The three asteroids flying along with Venus measure between 330 and 1,300 feet in diameter, making each one capable of leveling entire cities and setting off massive fires and tsunamis,” said the outlet.
In the study, the researchers brought up Potentially Hazardous Asteroid (PHA) 2024 YR4, an asteroid identified last December of its “city-killer” potential. Audacy reported in February that NASA expects that asteroid to “safely pass by Earth in 2032,” after it previously warned that the asteroid might be on a collision path towards us that year.
Still, the discovery demonstrated the risks associated with other asteroids near us, the study authors explained. To get a better understanding of the damage these space rocks could cause, the researchers recommend actually going into space.
“Among these, low-e Venus’ co-orbitals pose a unique challenge, because of the difficulties in detecting and following such objects from Earth,” they said. “While surveys like those from the Rubin Observatory may be able to detect some of these asteroids in the near future, we believe that only a dedicated observational campaign from... space-based missions near Venus… could potentially map and discover all the still ‘invisible’ PHA among Venus’ co-orbital asteroids.”