With NASA’s DART mission recently succeeding in deflecting an asteroid off course, you might think our planet is ranked when it comes to defending against incoming asteroids, but there are plenty of asteroids out there and the search for potentially dangerous asteroids is a work in progress.
According to the European Space Agency (ESA), there are now over 30,000 known near-Earth asteroids in our solar system. A near-Earth asteroid is defined as being close to Earth at some point in its orbit, as many asteroids have highly elliptical orbits that bring them closer to the Sun. Some times more than others.
Astronomers use a scale called an astronomical unit (AU), which is the distance between the Sun and Earth. Near-Earth asteroids are those within 1.3 AU from the Sun.
Not every near-Earth asteroid poses a threat to the planet, as many are small enough that they burn up in Earth’s atmosphere while others travel in a way that does not intersect with Earth’s orbit. It is potentially dangerous and will be monitored by astronomers, according to Digitartlends.
Not every near-Earth asteroid poses a threat to the planet, as many are small enough to burn up in Earth’s atmosphere while others travel in a way that does not intersect with Earth’s orbit. It is potentially dangerous and will be monitored by astronomers.
But to identify potentially dangerous asteroids, they must be identified first – and that’s no easy feat. Tools like ESA’s Gaia, a space observatory on a mission to map all the stars in the Milky Way, could help by providing information on background stars seen when searching for asteroids.
“Because of Gaia, we know more about stars in the galaxy that serve as background asteroid observations,” Tineke Roegiers, community support for the Gaia mission, explained in a statement. “Asteroid positions are obtained against these background stars, so the better one knows where the stars are, The orbits of the asteroids can be calculated with greater accuracy.”
Once an asteroid is spotted, it must be monitored several times to determine its orbit and see if it will approach Earth, Marco Micheli, an astronomer at the European Space Agency’s Near-Earth Object Coordination Center, said, “Of course, any asteroid discovered near Earth qualifies to be a near-Earth asteroid. Earth, but there are many far from home.” “New things are observed over time, their movements studied, and using only a few data points from different nights, their future locations can be predicted, depending on the number and quality of observations, this can span decades.” , even hundreds of years into the future.
If you feel like you’re hearing more about dangerous asteroids than you’re used to, it may seem as if the threat from the sky is on the rise – but in fact, we’re getting a lot better at spotting them.
“The good news is that more than half of known near-Earth asteroids have been discovered in the past six years, which shows how much better our asteroid eyesight has been,” said Richard Moisel, head of planetary defense at the European Space Agency. 30,000 discoveries made, and with the construction of telescopes and new detection methods, it is only a matter of time until we find them all.”