[meteorite-list] Dealing With Threatening Space Rocks

From: Jerry <grf2_at_meteoritecentral.com>
Date: Thu, 20 Sep 2007 17:56:08 -0400
Message-ID: <9D6A24AE146C465EA458270A15027722_at_Notebook>

Great Name, and I suppose very appropriate at this stage of our
technological preparedness.
Jerry Flaherty
----- Original Message -----
From: "Ron Baalke" <baalke at zagami.jpl.nasa.gov>
To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
Sent: Thursday, September 20, 2007 11:53 AM
Subject: [meteorite-list] Dealing With Threatening Space Rocks


>
> http://www.esa.int/esaCP/SEM8SUB1S6F_index_0.html
>
> Dealing with threatening space rocks
> European Space Agency
> 20 September 2007
>
> Every now and then a space rock hits the world's media -- sometimes almost
> literally. Threatening asteroids that zoom past the Earth, fireballs in
> the
> sky seen by hundreds of people and mysterious craters which may have been
> caused by impacting meteorites; all make ESA's planned mission Don Quijote
> look increasingly timely.
>
> The uncertainty surrounding whether a meteorite impacted in South America
> recently highlights the need to know more about these pieces of natural
> space debris and their trajectories. ESA has always been interested in
> such
> endeavours and conducted a number of studies into how it might best help.
>
> Those studies showed that it is probably the smaller pieces of rock, at
> most
> a few hundred metres across, rather than the larger ones that we should be
> more worried about for the time being. A worldwide network of astronomers
> is
> currently cataloguing most of the larger objects, those above 1 km in
> diameter. A number of survey telescopes have taken up the challenge to
> detect as many as 90 percent of all near Earth objects down to a size of
> 140
> metres by around 2020. Only after this time will we know whether
> space-based
> observatories will be needed to find the rest.
>
> Part of the trouble with these small chunks of rock is fixing their
> orbits.
>>From the ground, it is very difficult -- sometimes impossible -- to
> determine their trajectory with enough precision to rule out impacts with
> our planet in the years to come. So, ESA have been concentrating on a
> mission to actually 'mark a cross' on small asteroids and check the state
> of
> the art of our technology. The Don Quijote mission is a project based on
> two
> phases. In the first phase, a spacecraft would rendezvous with an asteroid
> and go into orbit around it. It would monitor the asteroid for several
> months, precisely determining its position, shape, mass and gravity field.
>
> In the second phase, another spacecraft would slam into the asteroid at a
> speed of around 10 km/s, while the first spacecraft watches, looking for
> any
> changes in the asteroid's trajectory. In this way, a mission involving two
> spacecraft would attempt to be the first to actually move an asteroid.
>
> In preparation for dealing with small asteroids, ESA's Don Quijote is also
> starting small. In its current design, the first spacecraft, Sancho, could
> reach any one of 5 or 6 small, nearby asteroids. Each one is no larger
> than
> a few hundred metres in diameter. At present, the mission planners have
> chosen to concentrate on Apophis, a small asteroid that can swing
> dangerously close to Earth on the outwards stretch of its orbit around the
> Sun.
>
> If it becomes a reality, Don Quijote could launch sometime early in the
> next
> decade. Sancho would take some 25 months to reach its target. Once there,
> it
> would begin its groundbreaking study -- both literally and metaphorically.
>
> "The idea is to get the technology ready before you really need it," says
> Ian Carnelli, Technical Officer for the Don Quijote mission at ESA.
>
> In 1908, a 20-metre asteroid impacted the uninhabited Tunguska forest in
> Siberia, toppling trees and causing total devastation over an area of two
> thousand square kilometres. Scientists predict this type of event to occur
> about every 150 years. Next year's 100th anniversary of that impact will
> be
> yet another reminder of the need to learn about and become ready to deal
> with asteroids -- even the small ones.
>
> For further information contact:
>
> Ian Carnelli
> Don Quijote Technical Officer
> Tel: +31 71 56558117
> Email: ian.carnelli _at_ esa.int
>
> [NOTE: Images and weblinks supporting this release are available at
> http://www.esa.int/SPECIALS/GSP/SEM8SUB1S6F_1.html ]
>
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Received on Thu 20 Sep 2007 05:56:08 PM PDT