Nasa keeps a close eye on ‘potentially hazardous’ asteroids with the potential to do serious damage to human civilisation.
But not even the brightest minds of our species can guarantee that every single space rock has been accounted for – even if they’re speeding around at a frighteningly close distance to Earth.
Astronomers from Nasa and CalTech (The California Institute of Technology) have found a ‘Near-Earth object’ that’s pinballing around in an area of space between our planet and the sun.
It’s called 2019 LF6 and is one of just 20 ‘Atira’ asteroids – the name for objects which orbit the sun without ever travelling further than the point of Earth’s own orbit in which we come closest to our star.
The rock has also got the short ‘year’ of any known asteroid, which is the time it takes to complete a full circle around the sun.
It’s roughly one kilometre in size and orbits the sun every 151 days or so, swinging out beyind Venus before diving closer to the sun than Mercury.
It’s quite unusual for astronomers to glimpse objects of this size, which are relatively easy to spot and track.
‘You don’t find kilometer-size asteroids very often these days,’ said Quanzhi Ye, a postdoctoral scholar at Caltech who discovered 2019 LF6 whilst working with Tom Prince, the Ira S. Bowen Professor of Physics at Caltech and a senior research scientist at JPL, and George Helou, the executive director of IPAC, an astronomy center at Caltech.
Could a doomsday asteroid spark World War III?
‘Thirty years ago, people started organizing methodical asteroid searches, finding larger objects first, but now that most of them have been found, the bigger ones are rare birds.
‘LF6 is very unusual both in orbit and in size—its unique orbit explains why such a large asteroid eluded several decades of careful searches.’
The asteroid was discovered using the Zwicky Transient Facility, a state-of-the-art camera at the Palomar Observatory that scans the skies every night looking for ‘transient objects’ such as moving asteroids or exploding stars.
Its capable of spotting Atira asteroids, which are very tricky to identify.
“We only have about 20 to 30 minutes before sunrise or after sunset to find these asteroids.’ Ye said.
The asteroids do not orbit in the ‘plane’ of our solar system – unlike the planets, which really are arranged in a relatively flat angle which indicates they probably formed from discs of material surrounding the sun.
‘Both of the large Atira asteroids that were found by ZTF orbit well outside the plane of the solar system,’ said Prince.
‘This suggests that sometime in the past they were flung out of the plane of the solar system because they came too close to Venus or Mercury.’
In addition to the two Atira objects, ZTF has so far found around 100 near-Earth asteroids and about 2,000 asteroids orbiting in the Asteroid Belt between Mars and Jupiter.
Source: Read Full Article