Earth’s Unwelcome Visitors

Both were completely unrelated but coincidentally consecutive. And both events could have caused destruction and devastation to earth much more massive than what we have experienced.

Firstly, let us look at the meteorite incident. It flared through the sky of the Russia’s city of Chelyabinsk, of 1.1 million people, and broke apart some 15-20 miles above earth’s surface, triggering an atomic bomb-sized shock wave which blew out windows of several buildings. It left over 1200 people, including 200 children, injured, and made some Russians fear the end of the world.

Did you know that this 50-foot-wide (15-meter-wide), 7,000-ton rock zoomed down towards earth from outer space at an amazing velocity of 40,000 mph (18 kilometers per second or 64,800 km/hour)?!

According to NASA officials, the shock of atmospheric entry blasted the rock apart, releasing energy equivalent of 300 to 500 kilotons of TNT. That’s more than 10 times the energy released by the atom bombs that exploded over Japan at the end of World War II. NASA’s estimates, they say, are based on readings from infrasound sensors that were set up by the Comprehensive Test Ban Treaty Organization to detect nuclear blasts.

Interestingly, the meteorite entered earth at 55 degrees north latitude, the same latitude as northern England. So, it could have struck Britain if it had just entered the atmosphere after three or four hours, causing widespread damage in the British Isles.

The entry time of the meteorite was at 05.20 GMT/UTC when it was 09.20 in Chelyabinsk (and when it was 08.20 in Manama). After a few hours, the closest approach of asteroid to earth, near the Indonesian Island Sumatra, occurred at 19.24 GMT/UTC (when it was 22.24 in Manama).

So, let us now look at this asteroid incident. Named ‘2012 DA 14’ by astronomers, this asteroid which was three times bigger than the meteorite almost brushed the earth on its way back into outer space from where it came.

The fact that it was as close to earth as 17,200 miles (27,700 kilometers) above Earth’s surface means that though this distance is well outside Earth’s atmosphere, it is well inside the belt of our artificial satellites in geostationary orbit.

So, ‘Nile Sat’, the satellite that beams TV programmes – through our roof-top dishes – into our living rooms and bedrooms in Manama, is farther away than this asteroid path’s closest point to earth.

You can put it into an even better perspective when I tell you that the distance between Earth and asteroid was only about one-tenth the distance between Earth and moon! Our earth was that close to a brush with disaster, from our visitor from outer space.

Like many of you, naturally, I wondered why all our learned astronomers did not detect the coming of the meteorite into the Russian sky. Apparently, according to Paul Chodas who is a research scientist in NASA’s Near Earth Object Program Office, the reason is that it came out of daytime sky. It seems that it is nearly impossible to find and predict these ahead of time because telescopes can only spot meteor arrivals during the night.

Anyway, there are now discussions in scientific circles on whether this meteorite that hit Russia should actually be called an asteroid. But call it meteorite, asteroid, dwarf planet or planet. What’s in a name? We all know, any huge space object by any other name, would still damage us badly, if it hits us.

As humans we welcome visitors from other parts of our own planet. But as Planet Earth, we should probably put up a notice, ‘Visitors Not Allowed’

We do not want any unwelcome visitors in Planet Earth’s neighborhood. No. Thank you.