US Asteroid - Astronomers comment on asteroid that passed near Earth
TAPE: EF02/0532
IN_TIME: 23:09:02
DURATION: 1:32
SOURCES: ABC
RESTRICTIONS:
DATELINE: Various, 21 June 2002/ File
SHOTLIST:
1. Earth as seen from space
2. Animated graphics of asteroid travelling near Earth
Cambridge, Massachusetts - 21 June 2002
3. SOUNDBITE (English) Tim Spahr, Smithsonian Astrophysical Observatory
"There aren't very many objects that have approached this closely that we've known about, but this kind of thing happens several times a year and the objects are missed."
4. Animated graphic of asteroid
Lexington, MA - 21 June 2002
5. SOUNDBITE (English) Grant Stokes, Associate head of the Aerospace Division, MIT Lincoln Laboratory
"The atmosphere does a marvelous job of filtering out all the small stuff that comes by on a daily basis, and the pieces that get through only do it on hundred-year time scales."
New Mexico
6. Telescope
File - 1908
Tunguska, Siberia
7. Damaged forest after asteroid blast
Lexington, Massachusetts
8. SOUNDBITE (English) Grant Stokes, Associate head of the Aerospace Division, MIT Lincoln Laboratory
"I think people are going to have to get used to that, and used to seeing more of these events."
File
9. Missile launch
New Mexico
10. Wide shot telescope
11. Mid shot telescope
STORYLINE:
An asteroid the size of a football field hurtled past the Earth a week ago, missing what could have been a catastrophic collision by a mere 120-thousand kilometres (75,000 miles) - less than a third of the distance to the moon.
The miss was one of the nearest ever recorded for an object of that size, according to scientists.
The asteroid wasn't detected until three days after it sped past Earth on June 14. When such asteroids are detected they are usually spotted far from Earth when they are approaching or on their way out.
The asteroid, provisionally named 2002 M-N, was travelling at more than 36-thousand-800 kilometres per hour (23,000 mph) when it was spotted.
Light in weight but with a diameter of between 50 and 120 yards, 2002 M-N was big enough to have caused the kind of devastation experienced in Siberia in 1908, when an asteroid that exploded above Tunguska flattened nearly 1-thousand-280 square kilometres (800 square miles) of forest.
The asteroid's air blast was believed to have done the damage, since no crater was found.
The size of asteroids is estimated by measuring their brightness, without knowing their composition. In general, damage on the ground depends on what an asteroid is made of, varying from solid metal to a loosely bound aggregate.
Asteroids the size of 2002 M-N are estimated to hit the Earth every 100 to several hundred years, causing local destruction but no damage to civilization or the planet's ecosystem.