Vellore Rock Unlikely to Be A Meteorite, Says Astro Prof
By Nandini Chandrashekar | ENS | Published: 07th February 2016 02:57 PM |
BENGALURU: Scientists from the Indian Institute of Astrophysics (IIA) in Bengaluru say that the object that killed a bus driver in Vellore district of Tamil Nadu on Saturday is unlikely to be a meteorite, as is being said.
The bus driver was hit by a splinter from an object that crashed into the ground with a deafening sound at a private engineering college. Three others sustained injuries in the incident.
It was initially suspected to be an explosion of abandoned gelatine sticks, although eyewitnesses said it was an object from the sky that crashed into the college. A thorough scouring of the site by a bomb squad and sniffer dog squad found no trace of any explosive substances.
Police did find a bluish rock at the impact site, and it was surmised to be a meteorite.
Associate professor Dipankar Banerjee of IIA, however, said it is not likely to have been a meteorite but more likely satellite junk.
"I will be very surprised if such a thing happened because of a meteor shower. Normally meteor showers are traceable and there are predictions for this. But there was no prediction of this," he said.
The calendar for meteor showers is released early and, according to the American Meteor Society, a meteor shower was indeed active from January 1 to January 10. The next meteor shower is expected only around April 16.
According to Prof. Banerjee, most even smaller meteor impacts are invariably tracked. Most space rock fragments easily burn up in the atmosphere.
"If it is a larger object then we will know. Which is how we know well in advance about the possibility of a shower,” he said.
True, extremely small fragments can be difficult to track, but such fragments are unlikely to be solitary objects. They are usually accompanied by many more and hence meteor showers are visible.
But could a meteorite have exploded upon impact, as the Vellore object seemed to have?
Prof. Banerjee said such fragments can explode if they are carrying charged particles, but that is unusual. Most fragments are neutral objects, so they cannot have a thermodynamic exchange. But if a charged body hits a transformer for instance, there is possibility of an explosion, he said.
So was it an piece of an abandoned satellite then?
The astrophysicist did not rule out that possibility what with satellites getting lost on a regular basis.
“Typically, space debris is also absorbed into the atmosphere and they fragment most of the time. But one cannot rule out that a broken piece of a satellite will never reach the earth. And yes, its velocity can be high enough to cause an explosion,” he said.