You may think a killer asteroid only exists in movies and video games. But when one’s about to collide with Earth—which has happened before!—that “fire” button on your controller won’t be much help. Fortunately, like good gamers, scientists are keeping their eyes on their screens and watching for incoming rocks.

Eyeing the Asteroids

The good news is that if an asteroid is heading straight for Earth, you will probably know about it years before it hits. Space agencies, including NASA and the European Space Agency, are working on methods to crash a spacecraft directly into an asteroid and nudge it off course. The Don Quijote mission proposes to do just that.

Be Prepared

If the efforts to deflect the asteroid fail, look out! An asteroid crashing into the ocean would cause a giant tsunami. Get as far away from the coast as possible. Highly populated areas are likely to be overrun with mobs, so head for a remote, rural area, far away from the impact zone. Gather as much food, water, and medicine as possible.

Global Consequences

The aftermath of an impact event would not be pretty. A large asteroid would create a giant cloud of debris that blocked out the sun. Temperatures would drop. In time, all plant life would die. The shockwaves might cause earthquakes and volcanic eruptions. Wildfires would likely break out. Basically, this is the worst of worst-case scenarios. Ideally, you could ride out the “impact winter” somewhere underground with large stockpiles of food and water, but let’s hope it won’t be necessary.

The Meteor Crater, near Flagstaff, Arizona, in the United States, is a mile (1.6km) wide.
Most asteroids are made of rock. They can be as small as a boulder or as large ashundreds of miles in diameter.

FAST FACT

• Apophis is an asteroid that will pass by Earth on April 13, 2029. And, yes, it’s a Friday! Scientists predict it will miss the planet by about 20,000 miles (32,187 km). That might seem far away, but that’s ten times closer to Earth than the Moon is. Talk about dodging a bullet.