26/06/2024
26/06/2024
NEW YORK, June 26: Later this week, a colossal asteroid dubbed 2011 UL21, nicknamed a "planet killer" due to its size, will come remarkably close to Earth, hurtling past our planet at speeds exceeding 58,000 mph (93,000 km/h). This mountain-sized object, classified as "potentially hazardous," is among the largest asteroids to pass near Earth in over a century, promising a rare celestial spectacle that can be viewed live.
2011 UL21 is categorized as a near-Earth asteroid, meaning its orbit periodically brings it within 1.3 astronomical units (AU) of the sun—approximately 1.3 times the distance between Earth and the sun. It completes a full orbit around our star every three years. Estimated to measure between 1.1 and 2.4 miles (1.7 to 3.9 kilometers) in diameter, according to SpaceReference.org, this asteroid ranks larger than 99% of known near-Earth asteroids, according to the European Space Agency (ESA).
Despite its imposing size, 2011 UL21 is significantly smaller than historical impactors like the asteroid that formed South Africa's Vredefort crater or the catastrophic Chicxulub impactor linked to the dinosaur extinction event. Nevertheless, its potential for continental-scale damage and atmospheric disruption in the event of an impact underscores its "planet killer" designation.
On June 27, 2011 UL21 will make its closest approach to Earth in recent history, passing within approximately 4.1 million miles (6.6 million km)—a distance closer than it has been in the last 110 years, as per simulations from NASA's Jet Propulsion Laboratory (JPL). While NASA categorizes it as a potentially hazardous object due to its proximity, it will still be about 17 times farther away than the moon.
Astrophysicist Gianluca Masi, director of the Virtual Telescope Project (VTP), highlighted the asteroid's significance, noting it as one of the largest to approach within 4.7 million miles (7.5 million km) of Earth since 1900.
Enthusiasts can witness this celestial event live through a free livestream hosted by the VTP, capturing views from the Bellatrix Astronomical Observatory in Ceccano, Italy. The livestream starts at 4 p.m. ET on June 27, with the asteroid's closest approach expected just 15 minutes later.
For those with telescopes, 2011 UL21 will be brightest on June 28 and June 29, visible from the Northern Hemisphere with proper equipment. Its luminosity will rival that of Proxima Centauri, the closest star to the sun, according to VTP.
This close approach marks a unique opportunity, as 2011 UL21 won't return this near to Earth until 2089, when it will pass within 1.7 million miles (2.7 million km)—more than twice as close as its current approach, according to JPL simulations.
While 2011 UL21 poses no threat to Earth presently or in the foreseeable future, it serves as a reminder of the ongoing celestial dance around our planet and the potential risks posed by near-Earth objects.