The known near Earth asteroid catalog now tops 30,000
The catalog of known near Earth asteroids that have been identified using a number of survey telescopes in space and on the Earth now totals 30,039. As defined at the link:
An asteroid is called a near-Earth asteroid (NEA) when its trajectory brings it within 1.3 Astronomical Units (au) of the Sun. 1 au is the distance between the Sun and Earth, and so NEAs can come within at least 0.3 au, 45 million km, of our planet’s orbit.
Currently, near-Earth asteroids make up about a third of the roughly one million asteroids discovered so far in the Solar System. Most of them reside in the asteroid belt between Jupiter and Mars.
NEAs are also called NEOs (Near Earth Objects). The chart above, produced by the Center for NEO Studies which tracks these objects, shows the number of NEAs discovered over time.
Of the 30,039 now known, about 1,400 have orbits with “a non-zero” chance of hitting the Earth. None however will do so in the next hundred years at least.
Though the pace of discovery is vastly improving — as indicated by the steep rise in the curve in the graph — only when that curve begins to flatten out will we know that we are getting close to having a more-or-less complete survey of these objects.
The catalog of known near Earth asteroids that have been identified using a number of survey telescopes in space and on the Earth now totals 30,039. As defined at the link:
An asteroid is called a near-Earth asteroid (NEA) when its trajectory brings it within 1.3 Astronomical Units (au) of the Sun. 1 au is the distance between the Sun and Earth, and so NEAs can come within at least 0.3 au, 45 million km, of our planet’s orbit.
Currently, near-Earth asteroids make up about a third of the roughly one million asteroids discovered so far in the Solar System. Most of them reside in the asteroid belt between Jupiter and Mars.
NEAs are also called NEOs (Near Earth Objects). The chart above, produced by the Center for NEO Studies which tracks these objects, shows the number of NEAs discovered over time.
Of the 30,039 now known, about 1,400 have orbits with “a non-zero” chance of hitting the Earth. None however will do so in the next hundred years at least.
Though the pace of discovery is vastly improving — as indicated by the steep rise in the curve in the graph — only when that curve begins to flatten out will we know that we are getting close to having a more-or-less complete survey of these objects.