Massive “Planet Killer” Asteroid 2011 UL21 to Make Close Approach to Earth on June 27

A massive asteroid, 2011 UL21, will make a close approach to Earth on June 27. Traveling at around 58,000 mph (93,000 km/h), the mountain-size space rock will pass within 5 million miles of Earth. This is one of the closest approaches by such a large asteroid in over a century. Measuring between 1.1 and 2.4 miles wide, 2011 UL21 is larger than 99% of known near-Earth asteroids.

Despite its size, 2011 UL21 poses no threat to Earth now or in the future. However, due to its potential to cause significant damage, it is classified as a “planet killer.” The closest approach will be around 4.1 million miles from Earth, closer than it has been in at least 110 years.

You can watch this event live through a free livestream from the Virtual Telescope Project (VTP), beginning at 4 p.m. ET on June 27. Additionally, the asteroid will be visible through telescopes, appearing brightest on June 28 and 29.

2011 UL21 won’t come this close to Earth again until 2089, when it will pass within 1.7 million miles. While there is no chance of a planet-killer asteroid hitting Earth in the next 1,000 years, smaller asteroids will have close encounters, such as Apophis in 2029.