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Take cover! Falling satellite 'could land' any time from tomorrow - and the 'strike zone' covers most of the planet
It ran out of fuel in 2005 and Nasa has no idea where it will crash land
It could hit any time from Thursday to Saturday (US time) this week
Around 26 pieces will hit the surface, in pieces weighing up to 300 pounds
By Ted Thornhill and Rob Waugh
Last updated at 3:54 PM on 21st September 2011
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Nasa scientists are working round the clock to tell us where and when a six-ton satellite will land this week - but the only thing that's certain is that pieces of it will hit the surface of the planet.
The 20-year-old satellite will, Nasa estimates, break into more than 100 pieces on re-entry, and some will burn up - but it's estimated that around 26 of the heaviest metal pieces WILL hit the surface - in lumps weighing up to 300 pounds. In total, 1,200 pounds of metal will hit.
Debris could be scattered over an area up to 500 miles long. Nasa says there’s a 1 in 3,200 chance pieces could hit someone. It would be the first time in history someone was injured by space debris.
Danger: The six-ton Upper Atmosphere Research Satellite will crash to Earth and could land in Britain
Danger: The six-ton Upper Atmosphere Research Satellite will crash to Earth and could land in Britain
The satellite could fall anywhere between the two latitudes, where billions of people live
The satellite could fall anywhere between the two latitudes, where billions of people live
The Upper Atmosphere Research Satellite, or UARS, ran out of fuel in 2005 and could land on any of six continents. NASA says it could land at any point between 57 degrees north and 57 degrees south - which includes almost all the populated areas of our planet (see map below).
Most of the satellite will burn up during re-entry, but a 1,200 pounds of metal metal will still plummet to the Earth’s surface.
Don't worry too much, though - the odds of any one particular person being hit are much lower, around one in 21 trillion.
It’s being tracked by the Joint Space Operations Center of U.S. Strategic Command at Vandenberg Air Force Base in California, but Nasa admits it has no idea where it will come down, or when.
The space agency said that the crash site will be anywhere between 57 degrees north latitude and 57 degrees south latitude and the remains could scatter over a 500mile area.
That means pieces of it could land in Scotland – or somewhere in Chile.
WHAT HAPPENS WHEN A SATELLITE FALLS TO EARTH?
Astronomer Dr Ian Griffin, from the UK Association of Science and Discovery Centres, says the Earth's atmosphere slows down falling satellites a great deal.
He explained that what remains of UARS will hit the ground relatively slowly and 'certainly not at orbital velocity of 17,500mph'.
Much of any satellite crashing to Earth will be disintegrated by heat, caused by friction with the atmosphere. It's the reason we get shooting stars - created by meteors burning up in the upper atmosphere. UARS is large enough, though, that up over a ton will strike the ground. It will not be in one piece, however: space vehicles experience incredible stress on re-entry. The load can be as much as 10Gs. An F1 car experiences around 5Gs with maximum braking from high speed.
The reason why the location of the crash site is so hard to predict is because the density of the atmosphere varies so greatly higher up, producing different amounts of drag.
A prediction that was wrong by even a few minutes would mean the satellite landing a huge distance away, owing to its speed.
However, a Nasa spokesman pointed out that there has yet to be any reported injury from falling space debris.
He said: ‘The risk to public safety or property is extremely small, and safety is NASA's top priority. Since the beginning of the Space Age in the late-1950s, there have been no confirmed reports of an injury resulting from re-entering space objects.
This satellite is far smaller than the 135-ton Russian space station Mir, which fell to Earth in 2001 or the 100-ton Skylab that fell in 1979. So far this year alone, two large Russian rocket stages have fallen to earth without inflicting any injury.
Mir fell into the South Pacific, while Skylab hit the Indian Ocean and parts of sparsely populated western Australia. Because two-thirds of the Earth is ocean, space debris usually hits water.
Nasa is urging anyone who finds a piece of the UARS satellite not to touch it.
The spokesman added: ‘If you find something you think may be a piece of UARS, do not touch it. Contact a local law enforcement official for assistance.’
It was launched back in 1991 by the Space Shuttle Discovery to measure ozone levels, wind speeds and temperatures in the stratosphere.
Junk yard in space: UARS is one of the thousands of objects in Earth orbit being tracked by Nasa, as shown by this computer graphic
Junk yard in space: UARS is one of the thousands of objects in Earth orbit being tracked by Nasa, as shown by this computer graphic
But now it’s one of 370,000 pieces of junk floating in space at speeds of up to 22,000mph.
The volume of debris was greatly increased by a 2007 Chinese anti-satellite weapon test and a 2009 crash-in-orbit of two satellites.
The widely criticised Chinese test used a missile to smash an aging weather satellite into 150,000 pieces of 1cm debris and 3,118 pieces can be tracked by radar on the ground.
The UARS is something of a relic - these days, Nasa satellites are designed to be light enough to burn up on re-entry, or to have fuel to fly up into a higher, longer-term orbit.
Take cover! Falling satellite 'could land' any time from tomorrow - and the 'strike zone' covers most of the planet
It ran out of fuel in 2005 and Nasa has no idea where it will crash land
It could hit any time from Thursday to Saturday (US time) this week
Around 26 pieces will hit the surface, in pieces weighing up to 300 pounds
By Ted Thornhill and Rob Waugh
Last updated at 3:54 PM on 21st September 2011
Comments (0)
Add to My Stories
Share
Nasa scientists are working round the clock to tell us where and when a six-ton satellite will land this week - but the only thing that's certain is that pieces of it will hit the surface of the planet.
The 20-year-old satellite will, Nasa estimates, break into more than 100 pieces on re-entry, and some will burn up - but it's estimated that around 26 of the heaviest metal pieces WILL hit the surface - in lumps weighing up to 300 pounds. In total, 1,200 pounds of metal will hit.
Debris could be scattered over an area up to 500 miles long. Nasa says there’s a 1 in 3,200 chance pieces could hit someone. It would be the first time in history someone was injured by space debris.
Danger: The six-ton Upper Atmosphere Research Satellite will crash to Earth and could land in Britain
Danger: The six-ton Upper Atmosphere Research Satellite will crash to Earth and could land in Britain
The satellite could fall anywhere between the two latitudes, where billions of people live
The satellite could fall anywhere between the two latitudes, where billions of people live
The Upper Atmosphere Research Satellite, or UARS, ran out of fuel in 2005 and could land on any of six continents. NASA says it could land at any point between 57 degrees north and 57 degrees south - which includes almost all the populated areas of our planet (see map below).
Most of the satellite will burn up during re-entry, but a 1,200 pounds of metal metal will still plummet to the Earth’s surface.
Don't worry too much, though - the odds of any one particular person being hit are much lower, around one in 21 trillion.
It’s being tracked by the Joint Space Operations Center of U.S. Strategic Command at Vandenberg Air Force Base in California, but Nasa admits it has no idea where it will come down, or when.
The space agency said that the crash site will be anywhere between 57 degrees north latitude and 57 degrees south latitude and the remains could scatter over a 500mile area.
That means pieces of it could land in Scotland – or somewhere in Chile.
WHAT HAPPENS WHEN A SATELLITE FALLS TO EARTH?
Astronomer Dr Ian Griffin, from the UK Association of Science and Discovery Centres, says the Earth's atmosphere slows down falling satellites a great deal.
He explained that what remains of UARS will hit the ground relatively slowly and 'certainly not at orbital velocity of 17,500mph'.
Much of any satellite crashing to Earth will be disintegrated by heat, caused by friction with the atmosphere. It's the reason we get shooting stars - created by meteors burning up in the upper atmosphere. UARS is large enough, though, that up over a ton will strike the ground. It will not be in one piece, however: space vehicles experience incredible stress on re-entry. The load can be as much as 10Gs. An F1 car experiences around 5Gs with maximum braking from high speed.
The reason why the location of the crash site is so hard to predict is because the density of the atmosphere varies so greatly higher up, producing different amounts of drag.
A prediction that was wrong by even a few minutes would mean the satellite landing a huge distance away, owing to its speed.
However, a Nasa spokesman pointed out that there has yet to be any reported injury from falling space debris.
He said: ‘The risk to public safety or property is extremely small, and safety is NASA's top priority. Since the beginning of the Space Age in the late-1950s, there have been no confirmed reports of an injury resulting from re-entering space objects.
This satellite is far smaller than the 135-ton Russian space station Mir, which fell to Earth in 2001 or the 100-ton Skylab that fell in 1979. So far this year alone, two large Russian rocket stages have fallen to earth without inflicting any injury.
Mir fell into the South Pacific, while Skylab hit the Indian Ocean and parts of sparsely populated western Australia. Because two-thirds of the Earth is ocean, space debris usually hits water.
Nasa is urging anyone who finds a piece of the UARS satellite not to touch it.
The spokesman added: ‘If you find something you think may be a piece of UARS, do not touch it. Contact a local law enforcement official for assistance.’
It was launched back in 1991 by the Space Shuttle Discovery to measure ozone levels, wind speeds and temperatures in the stratosphere.
Junk yard in space: UARS is one of the thousands of objects in Earth orbit being tracked by Nasa, as shown by this computer graphic
Junk yard in space: UARS is one of the thousands of objects in Earth orbit being tracked by Nasa, as shown by this computer graphic
But now it’s one of 370,000 pieces of junk floating in space at speeds of up to 22,000mph.
The volume of debris was greatly increased by a 2007 Chinese anti-satellite weapon test and a 2009 crash-in-orbit of two satellites.
The widely criticised Chinese test used a missile to smash an aging weather satellite into 150,000 pieces of 1cm debris and 3,118 pieces can be tracked by radar on the ground.
The UARS is something of a relic - these days, Nasa satellites are designed to be light enough to burn up on re-entry, or to have fuel to fly up into a higher, longer-term orbit.
