Emergency plan to deflect giant asteroid
Are asteroids our biggest threat? Scientists are now working on a plan to protect Earth from Didymos, a giant rock the size of Egypt’s great pyramid — one of 20,000 known near-Earth objects.
Next week, researchers from NASA and the European Space Agency will attend a conference in Rome to discuss the progress of an ambitious mission to deflect an asteroid in space.
The Asteroid Impact Deflection Assessment (AIDA) — a collaboration between the two space agencies — is designed to demonstrate that such a technique could work if we need to protect our planet from a collision with a large space object.
The target of AIDA is a double asteroid called Didymos — consisting of two bodies measuring around 2,560 and 525 feet in diameter respectively— which orbits the Sun between the paths of Earth and Mars.
American astronaut Rusty Schweickart explains that space rocks have struck Earth “millions of times” before.
“It will also happen in the future. But if we humans do our job correctly, this will never happen again.”
About 100 tons of meteoroids enter the Earth’s atmosphere each day and become meteors. Most burn up harmlessly, but records suggest they killed people in ancient China. And in 2013, a meteor exploded above Russia, injuring 1,000 people.
More worryingly, NASA estimates that 2,100 asteroids larger than 1km pass between the Sun and the edge of Earth’s orbit. A collision with one of them could destroy our soil and crops, threatening everyone on Earth.
Efforts to mine asteroids could help to find them, and some groups are trying to develop the technology to make them change direction away from Earth. But Schweickart says NASA is not tracking 99% of those which could wipe out a city on Earth — or 90% of those which could destroy countries.
Other factors could also cause the mass extinction of humanity: for example, climate crisis, nuclear war or artificial intelligence. But are rocks from space a bigger threat?
Not worth the worry?
We should invest more time and money to tackle it, say some. We know very little about asteroids, so we are unprepared.
That is an over-reaction, argue others. The catastrophic strike, which wiped out the dinosaurs, happened 65 million years ago. The human race is much more likely to be destroyed by its own hand, so that is where we should focus our attention.
- Are you worried about the threat from asteroids?
- Write down five questions about asteroids that you would like to ask Rusty Schweickart. Discuss with a partner why you chose those, and what answers you would expect.
Some People Say...
“If you don’t ponder the end of the world on a regular basis, I don’t think you’re really human.”Edan Lepucki, US novelist
What do you think?
Q & A
- What do we know?
- Scientists are working on developing at least two ways to make dangerous asteroids change direction, away from Earth. One plan involves gently pushing the asteroid slowly, over time, off its course and away from Earth. The other is to detect an asteroid early enough, so that it might be sent away using the gravity of a spacecraft.
- What do we not know?
- How seriously we should worry. The Planetary Society’s Emily Lakdawalla says that while this latest asteroid was concerning, “it is zero per cent danger to us. It’s the kind of thing where you learn about something that you didn’t know about, like things flying close by us, [which can make you] scared. But just like sharks in the ocean, they’re really not going to hurt you and they’re really fascinating to look at.”
- Stands for National Aeronautics and Space Administration that researches space and space exploration.
- A small rocky body, orbiting (going round) the Sun. The smallest ones are about one-metre wide. They are larger than meteoroids (see below).
- Small rocks in space are known as meteoroids. They become meteors (shooting stars) when they enter the Earth’s atmosphere.
- Luxembourg has recently given 200m euros to support mining. Two private US companies are investing in similar work to encourage spotting asteroids.
- Scientists at Oxford University have estimated a 9.5% chance of our species being wiped out during the next 100 years.
- Causing sudden, terrible damage.