Scientists are warning that at least three large, previously undetectable asteroids — each capable of wiping out an entire city — could one day hit Earth, with only weeks of warning time. A new study with researchers from Brazil, France and Italy, led by Valerio Carruba of São Paolo University, suggests there are multiple asteroids hidden by the sun’s glare in the inner solar system near Venus, Earth’s neighbour. There are three such asteroids in particular, 2020 SB, 524522, and 2020 CL1, that scientists say have orbits with the capacity to carry them dangerously close to Earth..PHEW!: NASA says asteroid no longer threatens the earth — but greater chance of moon collision.The asteroids are displaying erratic patterns with changing gravitational pull — making them difficult to track and unpredictable in their paths. Scientists have ascertained it’s possible their unstable paths could cross Earth's orbital track, resulting in a collision if they cross the track at the same time and point as planet Earth.The asteroids, referred to by scientists as “Venus co-orbitals” measure between 100 and 400 ms in diameter. Should they hit Earth, their impact would make a crater more than three kms wide and would level entire cities and cause mass combustion and tsunamis.The co-orbitals are hard to detect from Earth and poorly studied — but some of them could eventually drift into orbits that bring them dangerously close to our planet. Researchers don’t give a specific probability of impact.Though there are multiple of these “invisible” asteroids, the three in question pose a particular threat due to their extremely small Minimum Orbital Intersection Distance (MOID), which documents the distance between their orbit and Earth's orbit around the sun.The smaller the MOID, the higher the risk of a collision with Earth. These three asteroids have MOIDs of less than 0.0005 astronomical units (AU), which amounts to about 75,000 kms. For reference, this is a fraction of the distance to the moon, which is about 385,000 kms from Earth..SO YOU'RE SAYING THERE'S A CHANCE: NASA rapidly recalculating likelihood of asteroid colliding with Earth.The study, entitled, The invisible threat: Assessing the collisional hazard posed by the undiscovered Venus co-orbital asteroids, details the recent technology employed by the Rubin Observatory in Chile that allows scientists to spot the asteroids in certain spots in Venus’s atmosphere.Yet, there is still a substantial blind spot, so the window of warning is extremely short — a mere two to four weeks.“Twenty co-orbital asteroids of Venus are currently known,” wrote scientists in the report to the journal Astronomy and Astrophysics.“Co-orbital status protects these asteroids from close approaches to Venus, but it does not protect them from encountering Earth.”
