Armageddon time! How NASA plans to defend Earth from an asteroid

AUSTIN (KXAN) — This week, NASA is preparing to prevent the apocalypse. The space agency's DART Mission, which will launch a rocket into an asteroid, will serve as practice for when we inevitably have to prevent one of these cosmic rocks from colliding with the planet and wiping out the human race. Do we really need to prepare for an asteroid impact?

"Dinosaurs are definitely a sign that sort of stuff could happen," said Moriba Jah, Ph.D., a professor at the University of Texas and co-founder of Privateer Space. The space debris expert said we finally have the technology to prevent an impact.

How do we do this? Jah said it's relatively simple. "You want to be able to go out to it and give it a little nudge."

Space physics and preventing the end of the world

"A little nudge" sounds reductive, but thanks to physics, it's the truth. If a massive object like an asteroid is hurtling through space, a very, very slight change in its trajectory can change the path. Over time, that change could be enough to miss something as massive as a planet.

NASA's DART mission does just this. Also known as the Double Asteroid Redirection Test, the mission will crash a small probe into an asteroid. The asteroid, Dimorphos, will then be redirected using a rocket attached to the probe. The asteroid and its sister asteroid Didymos pose no risk to life on Earth.

Jah said DART will only work up to a certain size of asteroid.

Using light to redirect asteroids

Other ideas to redirect asteroids include using light photons emitted by the sun to alter an asteroid's course.

"If you paint them like a different color, solar radiation would start altering the trajectory of the object just based on its ability to reflect light," Jah said.

Light actually produces a tiny physical object called a photon. Think about sitting in a dark room and someone flicks on a light. You can actually feel the warmth from that light, maybe even feel where it is hitting. These are light photons.

By painting a black asteroid red or even white, the light spectrum would bounce off it. That impact over time is enough to redirect the asteroid. Remember that visible light is the light bouncing off an object that your eyes are able to see.

Too late, apocalypse time!

There are complications to both of these plans. "The closer the asteroid is, the harder it's going to be to deflect from the path," Jah said.

Detecting an asteroid before it gets too close requires spotting it ahead of time. But right now, Jah said "we don't have enough eyes on the sky."

Detecting asteroids is challenging. For one, space is big and dark. Light has to reflect off an object for us to see it. We also have a massive blind spot thanks to the sun. Its light is so powerful we can't see anything coming from its direction.

Jah said the number of satellites we've launched in recent years have also made observations from the ground challenging. We have more debris in orbit than ever before.

Many of theses satellites are outfitted with devices for tracking stars. Jah said these devices could be retrofitted to track asteroids instead.

For us to have any chance of survival, Jah said we must begin to catalog all objects in our space now. We must also observe them more frequently "to get a better accuracy and precision for probability of collision of any of these things with the earth."