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Asteroids:
treasures of the past and a threat to the future
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The Impact moment
on the Don Quijote mission: The Orbiter spacecraft (Sancho)
has retreated to a safe distance to observe how the Impactor
spacecraft (Hidalgo) crashes into the asteroid. After the
Impact Sancho will come closer and inspect the changes.
Credits: ESA - AOES Medialab
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3 April 2006
If a large
asteroid such as the recently identified 2004 VD17 – about
500 m in diameter with a mass of nearly 1000 million tonnes -
collides with the Earth it could spell disaster for much of our
planet. As part of ESA’s Near-Earth Object deflecting
mission Don Quijote, three teams of European industries are now
carrying out studies on how to prevent this.
ESA has
been addressing the problem of how to prevent large Near-Earth
Objects (NEOs) from colliding with the Earth for some time. In
1996 the Council of Europe called for the Agency to take action
as part of a “long-term global strategy for remedies
against possible impacts”. Recommendations from other
international organisations, including the UN and the
Organisation for Economic Cooperation and Development (OECD),
soon followed.
In response to these and other
calls, ESA commissioned a number of threat evaluation and mission
studies through its General Studies Programme (GSP). In July 2004
the preliminary phase was completed when a panel of experts
appointed by ESA recommended giving the Don Quijote
asteroid-deflecting mission concept maximum priority for
implementation.
Now it is time for industry to
put forward their best design solutions for the mission.
Following an invitation to tender and the subsequent evaluation
process, three industrial teams have been awarded a contract to
carry out the mission phase-A studies. :
a team with Alcatel Alenia
Space as prime contractor includes subcontractors and
consultants from across Europe and Canada; Alcatel Alenia Space
developed the Huygens Titan probe and is currently working on
the ExoMars mission
a consortium led by EADS
Astrium, which includes Deimos Space from Spain and consultants
from several European countries, brings their experience of
working on the design of many successful ESA interplanetary
missions such as Rosetta, Mars and Venus Express
a team led by QinetiQ
(UK), which includes companies and partners in Sweden and
Belgium, draws on their expertise in mini and micro satellites
including ESA’s SMART-1 and Proba projects
This month the three teams
began work and a critical milestone will take place in October
when the studies will be reviewed by ESA with the support of an
international panel of experts. The results of this phase will be
available next year.
No
reason for panic – yet
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The key moment of
the Don Quijote mission: the Impactor spacecraft (Hidalgo)
smashes into the asteroid while observed, from a safe
distance, by the Orbiter spacecraft (Sancho)
Credits: ESA
- AOES Medialab
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The risk is still small
however, and may decrease even further when new observations are
carried out. Still, if this or any other similar-sized object,
such as 99942 Apophis, an asteroid that will come close enough to
the Earth in 2029 to be visible to the naked eye, collided with
our planet the energy released could be equivalent to a
significant fraction of the world's nuclear arsenal, resulting in
devastation across national borders.
Luckily,
impacts with very large asteroids are uncommon, although impacts
with smaller asteroids are less unlikely and remote in time. In
1908 an asteroid that exploded over Siberia devastated an
unpopulated forest area of more than 2000 km²; had it
arrived just a few hours later, Saint Petersburg or London could
have been hit instead.
Fossils
of the Solar System
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The
target asteroid of the Don Quijote mission as it could be
seen from the Impactor spacecraft (Hidalgo) moments before
the imipact takes place.
Credits: ESA - AOES Medialab
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Asteroids are a part of our
planet’s history. As anyone visiting the Barringer Meteor
Crater in Arizona, USA or aiming a small telescope at the Moon
can tell, there is plenty of evidence that the Earth and its
cosmic neighbourhood passed through a period of heavy asteroid
bombardment. On the Earth alone the remains of more than 160
impacts have been identified, some as notorious as the Chicxulub
crater located in Mexico’s Yucatan peninsula, believed to
be a trace of the asteroid that caused the extinction of the
dinosaurs 65 million years ago.
Collisions
have shaped the history of our Solar System. Because asteroids
and comets are remnants of the turbulent period in which the
planets were formed, they are in fact similar to ‘time
capsules’ and carry a pristine record of those early days.
By studying these objects it is possible to learn more about the
evolution of our Solar System as well as ‘hints’
about the origins of life on Earth.
Comet 67P/Churyumov-Gerasimenko
is one of these primitive building blocks and will be visited by
ESA’s Rosetta spacecraft in 2014, as a part of a very
ambitious mission - the first ever to land on a comet. Rosetta
will also visit two main belt asteroids (Steins and Lutetia) on
its way to comet 67P/Churyumov-Gerasimenko. The mission will help
us to understand if life on Earth began with the help of
materials such as water and organisms brought to our planet by
'comet seeding'.
ESA’s Science programme
is already looking at future challenges, and its Cosmic Vision
2015-2025 plan has identified an asteroid surface sample return
as one of the key developments needed to further our
understanding of the history and composition of our Solar System.
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An image of Comet
67P/Churyumov-Gerasimenko. Our Solar System is home to one
star, nine planets and dozens of planetary satellites. It
also contains millions of asteroids and comets – the
left-over debris from the cosmic construction site that
created the planets and their moons.
Rosetta’s
task is to study these primitive building blocks at close
quarters so that scientists may gain new insights into the
events that took place 4600 million years ago, during the
birth of Earth and its planetary neighbours.
Credits: ESA
and European Southern Observatory
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Work still in
progress
Asteroids and comets are fascinating objects
that can give or take life on a planetary scale. Experts around
the world are putting all their energy and enthusiasm into
deciphering the mysteries they carry within them.
With an
early launch provisionally scheduled for 2011, Don Quijote will
serve as a ‘technological scout’ not only to mitigate
the chance of the Earth being hit by a large NEO but also for the
ambitious journeys to explore our solar system that ESA will
continue to embark upon. The studies now being carried out by
European industry will bring the Don Quijote test mission one
step nearer.
Note:
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Credits: ESA -
AOES Medialab
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Don Quijote is a NEO
deflection test mission based entirely on conventional spacecraft
technologies. It would comprise two spacecraft - one of them
(Hidalgo) impacting an asteroid at a very high relative speed
while a second one (Sancho) would arrive earlier at the same
asteroid and remain in its vicinity before and after the impact
to measure the variation on the asteroid’s orbital
parameters, as well as to study the object. Secondary mission
goals have also been defined, which would involve the deployment
of an autonomous surface package and several other experiments
and measurements.
The moments before impact...
The Impactor spacecraft (Hidalgo) heads towards the target
asteroid.
Credits:
ESA - AOES Medialab
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