Nasa and the European Space Agency have joined forces to protect Earth from asteroids.
Researchers and spacecraft engineers from across Europe and the US are meeting in Rome today to discuss a mission to ‘deflect’ a space rock and ‘prove the technique as a viable method of planetary defence’.
This mission is called the Asteroid Impact Deflection Assessment (AIDA) and will attempt to redirect the smaller part of a double asteroid called Didymos.
In the first stage of the mission, a spacecraft will smash into the space rock. Then a second ship will assess the crash site and gather data on the effects of the collision.
Nasa is already working on a craft called Double Asteroid Impact Test, whilst Italy will send a small CubeSat satellite to monitor the action.
The ESA mission is called Hera and will perform a ‘close-up survey of the post-impact asteroid’ and gathere measurements such as the asteroid’s mass as well as the size of the crater left behind after impact.
‘DART can perform its mission without Hera – the effect of its impact on the asteroid’s orbit will be measurable using Earth ground-based observatories alone,’ said Ian Carnelli, who is managing the Hera mission.
‘But flying the two missions together will greatly magnify their overall knowledge return. Hera will in fact gather essential data to turn this one-off experiment into an asteroid deflection technique applicable to other asteroids. Hera will also be the first mission to rendezvous with a binary asteroid system, a mysterious class of object believed to make up around 15% of all known asteroids.
‘And our mission will test a variety of important new technologies, including deep space CubeSats, inter-satellite links and autonomous image-based navigation techniques, while also providing us with valuable experience of low-gravity operations.’
The main body of Didymos is roughly 780 metres wide across, with its ‘moonlet’ about the size of Egypt’s Great Pyramid, stretching to about 160 metres wide.
Earlier this year, scientists warned that asteroids are stronger than predicted and said humanity could have a tough time destroying a doomsday space rock on a collision course with Earth.
They found that a huge impact would not turn a city-sized object into a harmless ‘rubble pile’, but leave it with ‘significant strength’.
The findings could have a massive influence on how our species deals with the threat posed by gigantic space rocks.
‘We are impacted fairly often by small asteroids, such as in the Chelyabinsk event a few years ago,’ said K.T. Ramesh of Johns Hopkins University.
‘It is only a matter of time before these questions go from being academic to defining our response to a major threat.
‘We need to have a good idea of what we should do when that time comes – and scientific efforts like this one are critical to help us make those decisions.’
Scientists are currently trying to work out what to do if an asteroid suddenly appears on the horizon.
The latest research considered what would happen if we smashed a kilometre-wide asteroid into another that’s 25-kilometres wide – which is easily big enough to wipe out life on Earth.
They found that ‘millions of cracks formed and rippled throughout the asteroid, parts of the [larger] asteroid flowed like sand, and a crater was created’ after the impact.
But after this, ‘the impacted asteroid retained significant strength because it had not cracked completely, indicating that more energy would be needed to destroy asteroids’.
This means we might find it very hard to just go up into space and nuke an asteroid, forcing us to adopt a different strategy to save our species from apocalypse space rocks.
“It may sound like science fiction but a great deal of research considers asteroid collisions,’ said Charles El Mir, lead author of a paper on the research.
‘For example, if there’s an asteroid coming at earth, are we better off breaking it into small pieces, or nudging it to go a different direction?
‘And if the latter, how much force should we hit it with to move it away without causing it to break? These are actual questions under consideration.’
The research was funded by the Nasa Solar System Exploration Research Virtual Institute.
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