A 45-metre (150-foot) asteroid on Friday hurtled toward the Earth’s backyard, destined to make the closest known fly-by for a rock of its size.
NASA said the asteroid would miss the Earth by 17,150 miles (27,600 km). But that’s still closer than many communication and weather satellites are to the planet. Scientists insisted those, too, would be spared.
Scientists at NASA’s Near-Earth Object programme at California’s Jet Propulsion Laboratory estimate that an object of this size makes a close approach like this every 40 years. The likelihood of a strike is once every 1,200 years. The fly-by provides a rare learning opportunity for scientists eager to keep future asteroids at bay.
‘We are in a shooting gallery’
“We are in a shooting gallery, and this is graphic evidence of it,” said former Apollo astronaut Rusty Schweickart, chairman emeritus of the B612 Foundation, committed to protecting the Earth from dangerous asteroids.
Asteroid 2012 DA14 is too small to be visible to the naked eye even at its closest approach, which will occur around 1925 hours GMT (0055 IST Saturday), over the Indian Ocean near Sumatra.
The best viewing locations, with binoculars and telescopes, are in Asia, Australia and eastern Europe. Even there, all anyone can see is a pinpoint of light as the asteroid zooms by at 17,400 mph (28,000 kph).
As asteroids go, DA14 is a shrimp. The one that supposedly wiped out the dinosaurs 65 million years ago was 6 miles (9.6 km) across. But this rock could still do immense damage if it struck, releasing the energy equivalent of 2.4 million tonnes of TNT and wiping out 750 square miles (1,950 square km).
Most of the solar system’s asteroids are situated in a belt between the orbits of Mars and Jupiter, and remain stable there for billions of years. Some occasionally pop out, though, into the Earth’s neighbourhood. Mr. Schweickart noted that while 500,000 to 1 million sizable near-Earth objects, asteroids or comets were out there, yet, less than 1 per cent — fewer than 10,000 — have been inventoried.
DA14, which was discovered by Spanish astronomers last February, is “such a close call” that it is a “celestial torpedo across the bow of spaceship Earth,” Mr. Schweickart said in a phone interview.
Astronomers have organised asteroid-encounter parties.
