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News Science

Asteroid Hunting

Many of you will have seen the video of the meteor that exploded into the atmosphere above Russia last week, and I would just like to offer an overview of the event from a practical scientific prespective.

The meteor was about 15 metres across, and as such too small to detect. As we all saw though a meteor of this size can do extensive damage. It weighed about 7000 metric tonnes, travelling at 18 Km per second and exploded at a height of between 15 and 20 Km. This is pretty close to the ground if you think that an aeroplane flies at about 10Km and we are certainly not dealing with somewhere where nothing happens.

The force of the explosion was about 30 times that of the Hiroshima bomb, a pretty devastating blow by all counts. We should think ourselves lucky that it did not happen over a major city.

Trees blown over after the 1908 impact
Trees blown over after the 1908 meteor impact

In 1908 in Tunguska also in Russia a much larger meteor hit. This one was about the size of the DA14 meteor that flew past Earth later on the same day last week, and it blew trees down over an area of about 2000 square Km. Once again it hit over Siberia so less damage than could have occurred, but if you think that the event of last week over Russia only threw out about 5% of the force of this one than we don’t need much imagination to envisage the possible catastrophe. Several photos are available around the net and I offer one above. There are also plenty of huge craters to see.

NASA have the Near Earth Program, and they have the mission of monitoring the many things that fly close to Earth.

It is not an easy job though as you might imagine, they use ground based telescopes so can only see something that is big enough to reflect enough light, and last week’s hit came directly in line with the sun, so practically impossible to see.

NASA has managed to identify 90% of near Earth asteroids that are more than 1 Km across, and something of this size might threaten life on Earth itself if it hit. There are more than a million near Earth asteroids however that are 20 metres across or more but  very few of these have been identified and mapped.

The B612 Project is hoping to put a telescope into Space before 2018 that will be able to spot something of that size, but until then they will go largely unseen.

Keeping on a related topic last May I put a post up about asteroid mining, and recently the BBC has carried some updates on this project.

It is currently a 2 horse race, but it seems very speculative. And I remember a song about horses of this type.

Categories
News Science Space

Asteroid Mining

Last week an American Venture called Planetary Resources, Inc unveiled a plan to send a fleet of spaceship into near space to review the possibility of mining on asteroids.

Apparently there are thousands of asteroids close enough to make them attractive as they hold treasures worth fortunes in the form of platinum and other metals of the same group.

An asteroid with 'Property of X' marked on it
This one is mine!

Precious metals are not the only riches available however, and strangely enough plans are afoot to look for water. Water is an important material in space flight, because it can be used to produce the hydrogen and oxygen needed to power rockets, so an asteroid could represent a kind of modern day re-fueling station. This could make space travel cheaper because once rockets had left the atmosphere they could be refueled in space, eliminating the need to carry the excess weight during lift off.

All of this is in the future of course, but the project has plenty of backing from among others Larry Page of Google and filmmaker James Cameron.

These unfolding events bring some tricky questions however regarding the exploitation rights of near space objects. At the moment there is actually a subsection of international law called Space Law, governed by the Outer Space Treaty that was signed in 1967.

The writers did not envisage such monumental strides in technological advancement however and although the treaty makes clear that States cannot take celestial bodies as their own, they do retain jurisdiction and control over the object if they are the first to land on it.

A precedent has already been set as articles collected in Space have already been sold to private bidders by the Russian government. An article in this week’s wired goes into much greater detail.

It all looks a bit far fetched at times but supporters claim that the idea is no stranger than deep sea drilling for oil. It reminds me somewhat of the great gold rush events in the US of covered wagons and horses, only this time the means of transport differ and the digging is done by machine. Or maybe they will bring back entire asteroids and break them up on Earth, we will just have to wait and see. This article offers a glimpse at some possibilities.

There are obviously plenty of technological improvements required before any of this becomes concrete, but also a lot of legal and ethical issues need to be addressed. As ever one thing is certain, there’s big money in it for someone if it can be done!