UK plan to track asteroid threat
Pastor Dale Morgan
UK plan to track asteroid threat*
UK space scientists and engineers have designed a mission to investigate
a potentially hazardous asteroid.
The 300m-wide (984ft) rock, known as Apophis, will fly past Earth in
April 2029 at a distance that is closer than many communications satellites.
Astrium, based in Stevenage, Herts, wants a probe to track the asteroid
so its orbit can be better understood.
The concept will compete for a $50,000 (£25,000) Planetary Society
prize, but a full mission would cost millions.
The British design calls for a small, remote-sensing spacecraft, dubbed
Apex, which could rendezvous with Apophis in January 2014.
It would spend three years tracking the rock, sending data back to Earth
about the object's size, spin, composition and temperature.
From this information, orbit modelling would enable a more accurate
prediction of the risk of any future collision.
Early warning
Astrium says that if its concept won the prize, it would donate the
money to charity.
"The real prize for us would be if the European or US space agencies
thought there was merit in our proposal and asked us to carry the
feasibility study forward," said Dr Mike Healy, the company's space
science director.
A full mission would be expected to cost several hundred million dollars
to develop and launch.
Artist's impression of Apophis (Dan Durda/FIAAA)
Apophis could become a testbed for future defence strategies
Apophis caused some consternation in 2004 when initial observations
suggested it might hit Earth in 2029.
Further study by ground-based telescopes indicated there was virtually
no chance of this happening, and the expectation is that the object will
whiz past the Earth at a close but comfortable distance of just under
36,000km (22,370 miles).
Talk of a possible strike on the next visit in 2036 has also been
dampened by astronomers who have kept a careful watch over the rock's
progress through space.
Nonetheless, Apophis is considered a good target on which to practice
Earth-protection measures.
Were such an object to hit the Earth, it could cause devastation on a
country scale, leading possibly to the deaths of many millions of people.
Scientists say, however, that given sufficient warning, a potential
impactor could be deflected out of Earth's path.
Some have suggested such a rock might be nudged on to a safe trajectory
by hitting it with a small mass. Others have proposed flying a
spacecraft next to the object, to use gravity to tug the asteroid clear
of the planet.
Political support
The issue of asteroid or comet strikes is a topical one as researchers
continue to gather more information about their frequency during Earth
history.
At least one of the planet's mass extinction events - which included the
demise of the dinosaurs 65 million years ago - has been attributed to
the impact of a large space object.
Liberal Democrat MP Lembit Opik has campaigned for the research area to
be given more funding. His grandfather, renowned Estonian astronomer
Ernst Opik, did much to raise science's understanding of Earth-crossing
comets and asteroids.
The politician told the BBC News website: "The question isn't whether
Earth is hit by an asteroid - it is when.
"Good luck to Astrium; they are showing that if we have the political
will, we certainly have the technical know-how to do something about
threatening objects."
The US-based Planetary Society has organised its competition in
co-operation with the European Space Agency (Esa), the US space agency
(Nasa), the Association of Space Explorers (ASE), the American Institute
of Aeronautics and Astronautics (AIAA), and the Universities Space
Research Association (USRA).
The winning entry will be submitted to space agencies to see if they
want to carry the ideas through.