The number of identified asteroids that could crash into our planet now stands at 1,415, according to the record of the European Space Agency’s (ESA) Coordination Center for Near-Earth Objects.
The list is expanding at a rate of approx 200 new potentially dangerous asteroids per year as astronomers continue their systematic search for small, faint stars in near-Earth orbits.
None of the asteroids discovered so far represent an imminent risk. But the fact that there are so many, and so many yet to be discovered, led ESA and NASA to create programs called planetary defense.
The NASA DART mission that crashed into the asteroid Dimorphos had precisely the goal of learning how to deflect the trajectory of this type of star in case it arrives in the future towards Earth. This will be followed by ESA’s Hera mission which will visit the same asteroid in 2026 to analyze the result of the impact.
In addition to learning how to deflect asteroids, “it is very important to strengthen detection systems for near-Earth objects” to uncover the many that have not yet been identified, says Juan Luis Cano, of ESA’s Office of Planetary Defense.
of the 29,781 asteroids near the Earth discovered As of September 23, less than 5% have orbits that could lead them to collide with the planet. At the top of ESA’s list of potentially dangerous stars is an asteroid that is given a one in 14 chance of colliding with Earth (or about 7%).
The impact, if it occurs, will occur on September 5, 2095. Called 2010RF12, it travels at 12.29 kilometers per second (approximately 44,000 kilometers per hour). But it’s a small asteroid, about eight meters in diameter, so an impact could cause local damage, but not global devastation like that of the meteor that killed the dinosaurs.
Of the top 50 asteroids on ESA’s list, the one with the shortest-term risk is that it measures 60 meters in diameter and could hit Earth on 11 March. Its probability of impact is currently estimated at 1 in 490,196.
Because the impact risk is so low, this asteroid ranks 35th in the list of potentially dangerous asteroids. In the coming weeks, as more observations are made and its orbit is better understood, the probability of an impact in 2023 will likely drop to zero and the asteroid will be removed from the list.
More dangerous is a 30-meter star that will approach Earth on May 1, 2027 and has a 1 in 6,711 chance of impact. Although this probability is low, it could cause significant regional damage in the event of an impact there would be no time to send a mission like DART to divert its trajectory.
The most dangerous, not yet discovered
But the asteroids that concern planetary defense specialists the most are those that have not yet been discovered and are large enough to cause a cataclysm.
According to data from the ESA Planetary Defense Office, 82% of asteroids between 100 and 300 meters in diameter are still unknown. For those from 30 to 100 meters the percentage rises to 99%.
These are the types of asteroids that could be deflected by a mission like DART if they were to collide with Earth. For larger asteroids, nuclear weapons should be used, reports Juan Luis Cano. But to be able to deflect them, ESA’s planetary defense specialist says, they need to be discovered early enough and “for that we need to invest in means to discover near-Earth objects at a faster rate.”
The vanguard
Source: Clarin
