Asteroid 2012 DA14 in record-breaking Earth pass
16 February Daily Tselegraph, BBC
An asteroid as large as an Olympic swimming pool has raced past the
Earth at a distance of just 27,700km (17,200mi) the closest ever
predicted for an object of that size.It passed far closer even than the
geosynchronous satellites that orbit the Earth, but there was no risk of
impacts or collisions.Its closest approach was at 19:25 GMT.For regions
in darkness, it should remain visible until about midnight through good
binoculars or a telescope.
The asteroid's arrival was preceded by a damaging meteor event in
Russia on Friday but indications from the meteor's path suggest that the
two events are entirely unrelated - just a “cosmic coincidence”, as Alan
Fitzsimmons of Queens University Belfast told BBC News.
The asteroid orbits the Sun in 368 days a period similar to Earth's
year but it does not orbit in the same plane as the Earth.As it passes
at 7.8km/s (17,450 mi/hr) it will come from “under” the Earth and return
back toward the Sun from “above”.
It passed directly over the eastern Indian Ocean, making for the best
viewing in Eastern Europe, Asia and Australia.But keen viewers
everywhere used several live streams of the event on the internet,
including a feed from the Jet Propulsion Laboratory at Nasa.2012 DA14
was first spotted in February 2012 by astronomers at the La Sagra Sky
Survey in Spain - once a fairly small-scale, amateur effort to discover
and track asteroids that has in recent years become a significant
contributor to our knowledge of these “near-Earth objects”.
They caught sight of the asteroid after its last pass, at a far
greater distance.rom their observations, they were able to calculate the
asteroid's future and past paths and predict Friday's near-miss which
will be the closest the object comes for at least 30 years.Prof
Fitzsimmons said that it is a scientific opportunity not to be missed.
“When asteroids come this close, it's very important to try to learn
about them - it's become so bright, so it's so easy to study,” he told
BBC News.We get an additional insight into these small objects, which
are the most likely impactors on Earth.
The notion that it is these smaller, tens-to-hundreds of metres-sized
objects that pose the greatest potential threat to Earth is explored in
the BBC feature article Can we know about every asteroid? .The asteroid
will only be visible from some regions on Earth. Click through these
maps produced by Dr Geert Barentsen, of the University of Hertfordshire,
to see when the asteroid should be visible in different areas:
The asteroid due to zoom past Earth later this week could be worth
£125 billion ($195bn) - if only it was on a different orbit, according
to a space company.Asteroid 2012 DA14 is likely to contain a variety of
valuable resources including metals such as iron and nickel, and water
which can be used in space as rocket fuel.
But because the space rock's trajectory is tilted away from Earth,
the cost of sending a probe to mine it would be too high to make such a
pursuit worthwhile, experts said.
Asteroids are seen by some space companies as a valuable future
resource which could supply fuel for interplanetary missions and provide
metals to help build and repair satellites.
Water can be broken down into hydrogen and oxygen - two key
components of rocket fuel - while metals could be used to engineer new
or replacement parts for space equipment. Using these materials in space
would reduce the need for companies to launch fuel, water and building
materials into orbit, a process which currently costs £6.5 million
($10m) per tonne.
Deep Space Industries, a US firm which hopes to pioneer asteroid
mining, calculated that if just five per cent of the estimated amount of
water on 2012 DA14 were retrieved, it could be worth up to £42 billion
($65bn).If 10 per cent of the rock consisted of metals which could
easily be recovered they could be worth another £84 billion ($130bn),
the company added.The estimates were based on a presumed weight for the
asteroid of about 130,000 tonnes, although experts admitted it could
weigh as little as 16,000 tonnes or as much as one million tonnes.
David Gump, chief executive of the company, said: “Even with
conservative estimates of the potential value of any given asteroid, if
we begin to utilize them in space they are all the equivalent of a space
oasis for refueling and resupply.”
Asteroid 2012 DA14 is unsuitable for mining because its orbit around
the Sun is more inclined than Earth's, meaning it would take a vast
amount of energy to reach it, but DSI said there could be thousands more
which would be easier to “chase down”.
The company last month announced plans to send a fleet of probes to
examine asteroids passing Earth in 2015, before launching a mission to
return a sample to Earth within the next decade.Chairman Rick Tumlinson
said: “The challenge right now is to get out there soon so we can
inspect and sample them. Whether for mining, science or planetary
defence, we really need to begin getting close up and personal with
these objects.
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