Dealing with Asteroids and Other Space Hazards

In February of 2013, a meteor hurtled towards the region of Chelyabinsk, Russia. The meteor weighed about 10 tonnes! Fortunately, it broke into many pieces as it entered the Earth’s atmosphere. But it was not totally harmless. About 950 people were hurt by the falling debris. Even more people suffered property damage. This meteor event was not considered catastrophic. It did not even produce an impact crater. But it did make the world aware of the potential threat of a meteorite strike.   

How can we protect Earth from asteroids? 

The Inter-Agency Space Debris Coordination Committee is an alliance of 13 of the major national space agencies. Their goal is to devise methods to protect people from potential threats from space. The alliance monitors space weather. It also tracks near-Earth objects and other potentially harmful space debris. 

There are two different ways to deflect asteroids approaching Earth. The first is to deflect the asteroid with a kinetic impact technique. An example of this is NASA’s Double Asteroid Redirection Test (DART). NASA plans to launch DART in 2021 to redirect the asteroid Didymos. DART will do this by crashing into Didymos’ moonlet. A moonlet is a small body orbiting a primary body, a little like a small moon.

The second method is to alter the path of an asteroid with a gravity tractor. That’s a large spacecraft that would fly alongside an asteroid for years, or even decades, to slowly divert its path so that it doesn’t hit Earth.   

Why do scientists monitor space debris?

Scientists aren’t only concerned about asteroid impacts with Earth. They also track and monitor all matter of space debris. They make sure space debris don’t collide with and damage important satellites. This is because damage to satellites can take many years and many millions of dollars to replace. The US military is currently tracking about 20 000 space objects. They have also catalogued a further 20 000 objects since the launch of Sputnik in 1957. 

Did you know?

Scientists estimate that approximately 500 000 pieces of space debris larger than a marble are currently orbiting Earth. Approximately 20 000 of these pieces may be larger than a softball!  

What is space weather? 

Scientists also monitor space weather. Space weather refers to the physical processes on the surface of the Sun that can impact Earth. For example, scientists monitor solar flares and coronal mass ejections (CMEs). Solar flares consist of intense bursts of radiation. CMEs consist of large explosions of overheated plasma. Both of these phenomena produce solar radiation, which is responsible for much of the radiation that we experience here on Earth.  

You might not realize it, but there’s a lot going on in space. Fortunately, scientists are always keeping the best interest of Earth in mind!