Science in the News (February 17, 2007)
-- Asteroids / Bionic Eyes
(Top Posts - Science - 021707)

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Action plan for killer asteroids
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At the moment, Nasa is monitoring 127
near-Earth objects (NEO) that have a
possibility of hitting the Earth.


The threat of an asteroid hitting the Earth
is being taken more and more seriously
as more and more NEOs are found.

In the US, Congress has charged Nasa
with the task of starting a more detailed
search for life-threatening space rocks.

"Congress has said that Nasa's efforts
to date are not sufficient to the threat,"
said the US space agency's Dr Steven

"They have changed Nasa's targets so
that the cataloguing and tracking of aster-
oids is part of its mandate."

Congress has asked the agency to mount
a much more aggressive survey.

At the moment, Nasa tracks all objects
greater than 700m (2,300ft) in diameter.
The agency's new goal is to track all
objects greater than 70m (230ft) in dia-

To do this, the agency needs to use a
new suite of telescopes.

Alternatives include building a new Nasa-
owned system or investing in other pro-
posed telescopes such as the Large
Synoptic Survey Telescope (LSST) or
the Panoramic Survey Telescope &
Rapid Response System (Pan-Starrs).


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How to Fight an Asteroid


Today there are more than 100 entries on
NASA's list of asteroids that just might pos-
sibly hit Earth, even if it's less than a one-in-
a-million chance. One of them, called Apo-
phis, currently has a risk rating of 1 in 45,000
- serious enough to get people thinking
about how to avoid a "cosmic Katrina."

Chances are that Apophis will soon no longer
be considered a threat, but what about those
others? And what about the thousands of
space rocks that are expected to be added
to the list over the next few years?

Somewhere out there is a killer asteroid with
our name on it, and scientists, astronauts,
diplomats and space law experts are just
starting to draw up a plan for dealing with it
- that is, once we figure out which asteroid
it is.


Schweickart said Apophis is just "an example
of thousands of things we're going to have
over the next 10 or 12 years," due to the
expanded Spaceguard Survey. He pointed
to a wavy line going over a map of the earth,
representing the places where Apophis could
hit in a worst-case scenario for 2036.

By 2020, he said, "we're going to find a hun-
dred or more lines across the planet like

Chesley estimated that there were about
20,000 medium-size, potentially threatening
asteroids out there, waiting to be found,
and a chart he showed during today's pre-
sentation indicated that more than 3,000
of them could be cataloged during just one
year, 2011.

The trick, he said, is to "find them as early
as possible" so that there's plenty of time
to come up with a strategy in case some-
thing has to be done.


"We can prevent an asteroid impact ... to
enhance the survival of life on Earth. Now,
if we don't do that, we're not that far past
the dinosaurs."

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Trials for 'bionic' eye implants


A bionic eye implant that could help restore
the sight of millions of blind people could
be available to patients within two years.


Retinal implants are able to partially restore
the vision of people with particular forms
of blindness caused by diseases such as
macular degeneration or retinitis pigmen-

About 1.5 million people worldwide have
retinitis pigmentosa, and one in 10 people
over the age of 55 have age-related macular

Both diseases cause the retinal cells which
process light at the back of the eye to gra-
dually die.

The new devices work by implanting an
array of tiny electrodes into the back of the

A camera is used to capture pictures, and
a processing unit, about the size of a small
handheld computer and worn on a belt, con-
verts the visual information into electrical

These are then sent back to the glasses
and wirelessly on to a receiver just under
the surface of the front of the eye, which
in turn feeds them to the electrodes at the


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