Why It Matters: In NASA's first ever planetary defense test, the DART spacecraft successfully smashed into an asteroid while travelling at about 14,000 miles per hour. As the collision occurred Monday evening, telescopes located all over the world observed the event. Though we do not yet have the results on how exactly DART impacted the asteroid's orbit, it was the first step in an international effort to show that if an asteroid were to head Earth's way, we may be able to divert its path.

DART = Double Asteroid Redirection Test

• The asteroid DART collided with is called Dimorphos, Greek for "two forms." Dimorphos is a moonlet (or tiny moon) which orbits larger asteroid called Didymos, Greek for "twin." These asteroids do not pose any threat to Earth, "making them ideal save-the-world test candidates," The Associated Press explains.
• If the data gathered by scientists over the next weeks, months and years show that the impact made by the refrigerator-sized DART spacecraft did slightly change the orbit of Dimorphos around Didymos — NASA will have successfully demonstrated that they can divert an asteroid's path in space.
• What's next? Scientists will receive images from a tiny "tagalong" satellite camera made the Italian Space Agency, showing what happened before and after the collision. In 2024, the European Space Agency will launch a spacecraft called Hera to follow DART's path and observe impacts of the mission.

Big Picture: NASA tracks asteroids and comets which could potentially impact and damage Earth. According to NASA's research so far, there are currently no asteroids that will threaten Earth within the next 100 years. However, out of the estimated 25,000 asteroids close to Earth, less than half of them have been found and confirmed.

NASA explains that Monday's international mission "embraces worldwide cooperation to address the global issue of planetary defense."

Bam! NASA spacecraft crashes into asteroid in defense test (The Associated Press)

Click HERE to view photos taken from the single instrument attached to DART — a camera which was likely destroyed on impact — but sent back images to Earth before the collision.

Click HERE to watch DART's impact with the asteroid.