On the evening of Friday 21st September 2012, reports of
meteors being seen in the skys above the UK started to
appear.
The Kielder Observatory in the north of
England tweeted that a
fireball had been spotted which broke up into smaller pieces after
about 20 seconds.
When we think of shooting stars we normally think of lumps of
rock from space falling towards Earth. In the movies this
often leads to a heroic group of tough guys lead by Bruce Willis heading into space
to blow things up (see Armageddon for more details).
The truth is less spectacular but no less interesting.
Lots of meteors do come from elsewhere in the solar system, but
plenty come from closer to home as well.
Talking to the BBC, Dr Tim
O'Brien from the Jodrell Bank
Observatory said that the meteors could actually have been
"space debris". In other words, the shooting star that caused
so much interest may actually have been a lump of burning
trash!
Here are some facts about Space Debris that may interest
you:
- There are millions of objects orbiting the Earth, although most
of them are not much bigger than a grain of sand
- NASA know
of around 21,000 objects which are more than 10cm long (more than
big enough to cause some damage if they hit something) and keep a
close eye on any that might be dangerous to astronauts, satellites
or us here on Earth
- This flotsam and jetsam is travelling at more than 17,000 miles
per hour!
- Objects in orbit around Earth can be anything from scraps of
metal to whole nuclear reactors
- NASA estimate that at least one piece of space junk falls to
Earth every day (but don't worry, most of them are too small to be
noticed and burn up long before they get through the upper
atmosphere).
One famous piece of space junk that reached Earth was a Payload
Assist Module (that's a space rocket engine to you and me) which
crashed in Saudi Arabia on 12th January 2001. Although much
bigger objects have crashed in the past, this one made it down in
fairly good condition having fallen from 175km above the
ground.
A rocket stage module
crashed in the Saudi Arabian desert (c) NASA
So, next time you see a shooting star
do two things:
- Take a photo and send it to Planet Science
- Think to yourself, is that a stray asteroid from beyond Mars,
or just a spanner dropped by an astronaut on the International
Space Station?