- Near-Earth objects are tracked by NASA‘s Planetary Defence Coordination Office.
- Asteroids exploded within the Earth’s atmosphere in 1908 and in 2013 with more force than an atomic bomb.
- Other near-Earth objects have come close enough to be labelled “potentially hazardous asteroids” by NASA, but passed Earth safely.
NASA’s Planetary Defence Coordination Office consolidates data from NASA’s Center for Near Earth Object Studies and the International Asteroid Warning Network to keep a close eye on objects that could potentially pose a threat.
Here are five times near-Earth objects got a little too close for comfort.
In 1908, an asteroid flattened 800 square miles of forest near the Podkamennaya Tunguska River in Siberia, Russia
In what has become known as the “Tunguska event,” NASA reports that a 220 million-pound asteroid travelling at 33,500 miles per hour entered the Earth’s atmosphere above the Podkamennaya Tunguska River in Siberia, Russia, in 1908. It broke up about 28,000 miles from the ground.
Most of the asteroid was consumed in the explosion, so the blast didn’t leave an impact crater. There were also no reported casualties. It did, however, topple 80 million trees.
Researchers couldn’t reach the site until 1927 due to harsh weather conditions. They found trees with their branches and bark stripped away due to shock waves.
A meteor exploded over Chelyabinsk, Russia, in 2013 with the force of a nuclear blast
The “Chelyabinsk meteor” rocketed into the Earth’s atmosphere at 40,000 miles per hour and broke apart 12 to 15 miles from the ground, according to Space.com.
Reuters reported that the shockwave damaged buildings, shattered, glass and caused 1,200 injuries.
Months later, scientists recovered a chunk of the meteor from Lake Chebarkul in Russia. They estimated that the meteor had a diameter of about 56 feet and weighed 11,000 tons.
In the aftermath, NASA established the Planetary Defence Coordination Office.
An asteroid named 2017 BX slipped between the Earth and the moon in January 2017
The asteroid passed by at 162,000 miles away – roughly two-thirds of the way to the moon. At 13 to 46 feet across and 16,600 miles per hour, it was too small and slow to pose any real threat. But INSIDER’s Dave Mosher wrote that its last-minute detection was “just another example of how blind we are to the millions of NEOs that could smack into our planet and release many atomic bombs’ worth of energy.”
In April 2017, a “potentially hazardous” asteroid as big as a skyscraper flew within 1.1 million miles of Earth
Because it flew so close to Earth (roughly 4.6 times the distance from our planet to the moon), asteroid 2014 JO25 earned the label of a “potentially hazardous asteroid,” or PHA. But NASA said the 2,000-foot rock would “fly safely past Earth” and isn’t due to appear again for more than 400 years.
An asteroid measuring 157 to 360 feet wide was only discovered one day before it flew by Earth in April 2018
An asteroid NASA dubbed 2018 GE3 flew 119,400 miles from Earth, about half the distance between Earth and the moon, in April 2018.
NASA estimated that the asteroid measured three to six times as big as the meteor that exploded over Chelyabinsk. Scientists spotted it just 21 hours before it flew closest to Earth, but said there was no chance of it making an impact.