After avoiding catastrophe on election day in the US, in the form of asteroid 2018 VP1 of course, NASA is now warning of another three space rocks headed this way, while also suggesting the ‘planet-killer’ Bennu may be hollow.
As 2020 draws to a close, the threat from outer space remains as clear as ever, with three asteroids over 30 meters in diameter traveling Earth’s way this week alone, starting on November 10 with a double-header.
Measuring roughly half the size of the Statue of Liberty (46m), asteroid 2020 UN3 will pass the planet at a safe distance of 4.4 million kilometers. Not long after, and almost double the size, the 72-meter 2020 UL3, will shoot past at 5.8 million kilometers.
Lest anyone get too comfortable, however, on November 12, asteroid 2020 VC, measuring 34 meters in diameter or roughly half the wingspan of a 747 jet, is set to buzz the planet at a distance of 5.2 million kilometers.
Honorable mention goes to 2018 VS4, 23 meters in diameter (roughly half as tall as the Arc de Triomphe) and the 27-meter 2020 VC1 (half the Leaning Tower of Pisa), both of which will make a flyby of Earth this week but are not expected to pose any threat to humanity.
Meanwhile, data from NASA’s Osiris-Rex spacecraft, which recently pillaged the potential planet-killer asteroid Bennu for some of its dust, indicates this particular headline-stealing space rock may, in fact, be hollow.
Furthermore, not only is Bennu likely hollow, but it is also spinning rapidly, driving material to its surface and potentially tearing itself apart in the process.
Still some 321,868,800km away, Bennu has a one-in-2,700 chance of impacting Earth between 2175 and 2199.
In a recent study, University of Colorado researchers managed to calculate its gravity – and thus its mass – by tracking the motion of rocks flung outwards by the asteroid before they crashed back down on its surface. The findings lead the boffins to suspect that Bennu has an empty core.
“It’s as if there is a void at its center, within which you could fit a couple of football fields,” Daniel Scheeres, who led the research, explained.
The latest data from the asteroid indicates that it completes one rotation every four hours, but that its rate of spin is increasing.
“You could imagine maybe in a million years or less, the whole thing flying apart,” Scheeres said.
The NASA team behind the incredible mission also found that Bennu’s rock was surprisingly soft, after the Osiris-Rex probe blasted the surface with a burst of nitrogen gas, rustling up much more material than expected, catching everyone off guard.