While the chances of an alien invasion coming to Earth and wiping out humanity are incredibly low, there are still interstellar threats to our global existence. One of the biggest is asteroids, but NASA is working on a solution to prevent that from happening.
For the first time ever NASA and the European Space Agency (ESA) are teaming up for a test of their proposed planetary defense plans. The space agencies will be launching a probe to try and divert an asteroid called Didymos out of its current orbit.
Didymos is not on course to hit Earth, and is not a threat to humanity. Instead NASA and the ESA are using this asteroid to practice diverting an asteroid from its path in case a different asteroid does start heading towards Earth in the future. While small asteroids hit the Earth all the time, a large asteroid could cause tremendous damage if it were to hit the planet, and could even possibly cause an extinction level event. An asteroid is believed to be the cause of the extinction of the dinosaurs.
Now Didymos is about the size of the Great Pyramid in Giza. While that's pretty big and would cause considerable damage to wherever it hits the Earth, it's unlikely it would cause an extinction-level event. But scientists want to practice their defense test on Didymos so they'll know how to react if a larger asteroid heads towards Earth.
NASA and the ESA are planning to launch their test in either 2020 or 2021, but the probe would not reach Didymos until October 2022. So hopefully no giant asteroids head towards Earth until then.