Most of the time we rush through space without giving it a second thought. But every now and again the Universe reminds us that we are not alone.
On Saturday morning, 16 February, Earth will be buzzed by asteroid ‘2012 DA14’. Its closest approach at 6:25am, will bring it 34,000km from Earth. That’s just a little closer than the geosynchronous satellites – a ring of communication and weather satellites that orbit the Earth at 36,000km. Earlier predictions had the asteroid coming even closer, but Earth’s gravity keeps tugging on the asteroid and changing its predicted path, ever so slightly.
The path of asteroid 2012 DA14, which approaches Earth from "below" and passes through the ring of geosychronous satellites. The times given are AEDT.
One thing is quite clear – there is no chance the asteroid will collide with Earth and that’s a good thing. At 45 metres across, it’s not particularly small and probably of similar size to the asteroid that exploded over Siberia in 1908. Known as the Tunguska event, it flattened 80 million trees across an area the size of Port Phillip Bay.
The path of asteroid 2012 DA14 across the south-west sky as seen from Melbourne on the morning of Saturday 16 February 2013. The times indicated are in AEDT while the positions with relation to the horizon are calculated for 5:25am.
Source: Melbourne Planetarium
Asteroid 2012 DA14 won’t be bright enough for us to see, but experienced observers could catch a glimpse with a small telescope. It will appear in the south-west, just below the Southern Cross – the hard thing will be pin-pointing it while it’s zipping along at 28,000 km/hour.
The rock was discovered almost a year ago by the La Sagra Observatory in southern Spain. It’s one of a handful of observatories that hunt and monitor Near Earth Objects. Each day, about a hundred tons of interplanetary material falls onto Earth – mostly dust from comets or small fragments from asteroid collisions. But once every 100 years, we expect something larger, like 2012 DA14, to appear. It’s nice to know there are people out there looking and making sure our path is clear.
The Tunguska event was caused by a similar sized asteroid exploding over Siberia in 1908.
Source: the Leonid Kulik Expedition
A Ustream feed of the flyby from a telescope at NASA's Marshall Space Flight Center in Alabama, will be broadcast from 1pm to 4pm, 16 February (AEDT).
Animations and interviews by NASA scientists
Accounts of the Tunguska event from Science at NASA