I’m old enough to (sort of) remember the old Asteroids computer game. Altough life on Earth is not quite as dogged by pieces of comets and interstellar debris hunting you around as was the case for the hero of the game, it turns out we have more to fear from asteroids than previously thought – or, as the BBC so charmingly put it, we ‘underappreciate’ the risk.
“Between 2000 and 2013, a network of sensors that monitors Earth around the clock listening for the infrasound signature of nuclear detonations detected 26 explosions on Earth ranging in energy from 1 to 600 kilotons – all caused not by nuclear explosions, but rather by asteroid impacts. These findings were recently released from the Nuclear Test Ban Treaty Organization, which operates the network,” the group says on its website, adding that:
“To put this data in perspective, the atomic bomb that destroyed Hiroshima in 1945 exploded with an energy impact of 15 kilotons. While most of these asteroids exploded too high in the atmosphere to do serious damage on the ground, the evidence is important in estimating the frequency of a potential “city-killer-size” asteroid.”
According to several media, the 2014 US budget is likely to include a $100 million post for a NASA project exploring the possibility of mining asteroids.
The basic idea goes something like this: a robot carrying a propulsion unit and a capture bag is sent to an asteroid. The ideal candidate weighs around 500 tonnes and have an orbit that brings it close to Earth. The robot then uses the propulsion unit to maneuver the asteroid into an orbit around the Moon, leaving it perfectly placed for astronaut prospectors to come and take a closer look.
All of this is scheduled to take place some time around 2025 and a mission like the one described above is budgeted to cost around $2.65 billion.
Asteroids are thought to carry large deposits of valuable and rare metals, which is the rationale behind (potentially) roping them in.
It’s either that or buy them off China. And it might be a hint of how USA feels about buying them off China…
According to a new study, Earth seems involved of bad, bad Christmas presents. Every year our planet seems to snap up a moon, but it usually doesn’t take it more than 12 months to tired of it and send it hurtling out into space again. Then it picks up another moon, but less than twelve months later, it grows bored with that one, and round and round we go. Oh, that’s a really poor pun isn’t it? Well, point for me then!
The new study in question has been published on arxiv.org and is called “The Population of Natural Earth Satellites”.
In it, Mikael Granvik, Jeremie Vaubaillon and Robert Jedicke talk of how Earth, at any given time, has what they term a ‘temporarily captured orbiter’.
The reason you haven’t noticed this is that the objects in question are quite a bit smaller than the object we know as our Moon. Actually they’re usually not more than a metre in diameter.