The 460-foot-long Asteroid 2013 ET is set to whizz past Earth on Saturday – the latest in our planet’s galactic ‘pinball contest’. Earlier in the day, the 2013 EC20 passed even closer, and both within a month of the Chelyabinsk meteor’s Earth strike.
The enormous piece of space debris is expected to pass just 2.5 lunar distances from planet Earth – the moon is approximately 384,400 km (238,000 miles) from us, meaning the asteroid’s flyby will be at a distance of about 950,000km (600,000 miles).
Some astronomers have compared its size to that of a city block, others a football pitch. Its dimensions were widely given as 460 feet (140m) long and 210 feet (64m) wide. A professional American football field is 360 feet by 160 feet, which would make this asteroid 100 feet longer than a football field, and 50 feet wider, should it live up to calculations.
Celestial bodies: What’s the difference?
A meteor is a ‘shooting star’, or the flash of light seen when a small chunk of space debris burns up in the Earth’s atmosphere. However, the word does not refer to the debris itself – this is a meteoroid.
A meteoroid is the interplanetary matter –a small rock or piece of space debris that burns up in the Earth’s atmosphere and is the source of the meteor.
A meteorite is a meteoroid that survives the falling through the Earth’s atmosphere and subsequently collides with the Earth’s surface.
Asteroids are generally larger chunks of matter from space, and tend to come from the asteroid belt located between the orbits of Mars and Jupiter.
Comets are asteroid-like objects, but have a visible atmosphere called a ‘coma’ which resembles a kind of ‘shell’ and/or ‘tail’, created by ice, ammonia, or other compounds.
Asteroid 2013 ET was first detected on March 3 by the Catalina Sky Survey based at the University of Arizona, and now approaches the planet less than a week after it first hit astronomers’ radars.
It will not be quite bright enough to view through standard personal binoculars or small ‘backyard’ telescopes, but will be visible using larger, professional devices in observatories, one of which will broadcast its passage online.
Although it was due to be shown via live webcast by the Virtual Telescope Project in Ceccano, Italy, at 19:00 GMT, strong rain and clouds have prevented it from broadcasting the event. Now the online Slooh Space Telescope, based in the Canary Islands, has taken the reins, and will give a live webcast from their observatory at 20:15 GMT.