A giant ‘planet killer’ asteroid will come ‘very close’ to Earth, which could cause dramatic climate change if it were to impact our planet.
The space rock, 2011 UL21, is about the size of Mount Everest, making it one of the largest “potentially hazardous asteroids” to pass by our planet in 125 years.
2011 UL21 is expected to come within six million kilometers of Earth on June 27, its closest approach in 110 years; the asteroid orbits the sun approximately every 1,130 days.
But skygazers may be able to spot the space rock with a decent telescope, especially on June 28 and 29, when it will be brightest.
A giant ‘planet killer’ asteroid will make a ‘very close’ approach to Earth, which could cause dramatic climate change if it makes an impact
“This asteroid is larger than 99 percent of all known objects near Earth,” the European Space Agency shared in an announcement.
‘However, it won’t come nearly as close to Earth. At its closest point on June 27, it will be more than seventeen times as far away as the moon.’
The asteroid is expected to return to Earth in 2089, when it will come within 1.7 million miles of our planet.
2011 UL21 was documented on October 17, 2011 by the Catalina Sky Survey project, a series of telescopes in Arizona.
The asteroid is estimated to have a diameter of over 2,000 meters.
“2011 UL21 is quite large and falls into the category of Apollo asteroids,” the SETI Institute said.
‘Named after the Greek god Apollo, who was known for his epic journeys, these asteroids come in a range of sizes, from a few meters to several kilometers in diameter, such as 2011 UL21.
“More importantly, Apollo asteroids get up close and personal by crossing Earth’s orbit, even though their orbits around the Sun are larger than Earth’s.”
2011 UL21 is expected to come within six million kilometers of Earth on June 27, its closest approach in 110 years – the asteroid orbits the Sun about once every 1,130 days
Astronomers have been closely watching 2011 UL21 for months, monitoring its trajectory to make sure people on Earth are safe.
“The term ‘Potentially Hazardous Asteroid’ (PHA) is a precise formal definition, which refers to small planets larger than about 140 meters and that could come within a radius of 7.5 million kilometers from Earth,” says Gianluca Masi , astrophysicist and scientific director of the Virtual Telescope Project which is organizing a livestream for the event.
“In other words, only the largest asteroids that can get close enough to our planet are marked as PHAs, which doesn’t mean they will hit Earth, but they nevertheless warrant closer monitoring.”
2011 UL21 is also categorized as a ‘planet killer’, which is defined as an asteroid that could cause damage on a continental scale and would produce enough debris upon impact that would cause significant climate changes. LiveScience reports.
Scientists at the Massachusetts Institute of Technology revealed in 2023 that an asteroid in that category would not impact Earth for the next 1,000 years.