A pair of ‘planet-killing’ asteroids — one recently discovered and another towing its own moon — were caught on video by NASA as they hurtled past Earth last week.
Scientists with the US space agency’s Jet Propulsion Laboratory (JPL) in Southern California tracked and imaged the two monster space rocks via the 230-foot-wide Goldstone Solar System Radar, which also measured these objects’ dimensions.
Asteroid 2024 MK, first spotted just 13 days before it came its closest to Earth, was determined to be a 500-feet long, ‘elongated and angular’ object per NASA’s radar that captured it skim our planet on Saturday.
And asteroid 2011 UL21, a nearly mile-wide object that sped by Earth on Thursday at 58,000 miles per hour, was seen with a ‘moonlet’ orbiting about two miles from its surface.
Asteroid 2011 UL21 (top row), a nearly mile-wide object which sped near Earth at 58,000 miles per hour, was imaged by NASA with a ‘moonlet’ (bottom row) orbiting 1.9 miles from its surface
The European Space Agency (ESA) which collaborates with NASA on planetary defense minced no words regarding the late identification of asteroid 2024 MK.
‘An asteroid this size would cause considerable damage,’ ESA officials said.
‘So its discovery just […] before it flies past our planet highlights the ongoing need to improve our ability to detect and monitor potentially hazardous near-Earth objects (NEOs),’ the agency noted.
First recorded on June 16th by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) in South Africa, asteroid 2024 MK’s orbit has now been altered by its incredibly close encounter with Earth’s gravitational pull.
The object zoomed in between the distance between Earth and the moon’s orbit, coming within about 184,000 miles from the surface of our planet’s atmosphere.
While NASA classified 2024 MK as a ‘potentially hazardous asteroid,’ NASA JPL reported that ‘calculations of its future motion show that it does not pose a threat to our planet for the foreseeable future.’
Dr Lance Benner, a planetary scientist at JPL who helped lead the tracking of these two killer asteroids, said that a true ‘near miss’ like this not likely again for decades, and that the US space agency worked hard to make the most of it.
Asteroid 2024 MK (pictured) was first spotted just 13 days before it came its closest to Earth. NASA radar determined the space rock to be a 500-feet long, ‘elongated and angular’ object
The European Space Agency (ESA) which collaborates with NASA on planetary defense minced no words regarding the late identification of asteroid 2024 MK (radar images above). ‘An asteroid this size would cause considerable damage,’ ESA officials said
‘This was an extraordinary opportunity to investigate the physical properties and obtain detailed images of a near-Earth asteroid,’ Dr Benner said.
2011 UL21, which orbits our sun once approximately every 1,130 days, made its closest flyby of planet Earth in over a century with this recent passing.
NASA JPL was able to determine that this nearly two-mile in diameter planet killer was ‘roughly spherical’ thanks to its near miss on June 27th.
2011 UL21’s very close and high-speed transit also helped the Goldstone radar, also known as Deep Space Station 14 (DSS-14), discovered its orbital ‘moonlet’ asteroid.
‘It is thought that about two-thirds of asteroids of this size are binary systems,’ Dr Benner noted about this find.
Two ‘planet-killing’ asteroids – one discovered just two weeks ago and another towing its own moon – were caught on video by NASA as they hurtled past Earth
‘Their discovery is particularly important because we can use measurements of their relative positions to estimate their mutual orbits, masses, and densities, which provide key information about how they may have formed,’ he continued.
Like 2024 MK, NASA JPL reported that 2011 UL21 and the moonlet that makes it a ‘binary system’ are ‘potentially hazardous.’
2011 UL21 is, in fact, categorized as a ‘planet killer,’ according to LiveScience, which is defined as an asteroid capable of damage on a continental scale capable of blasting up enough debris on impact to trigger significant climate changes.
‘Calculations of its future orbits,’ they noted, ‘show that it won’t pose a threat to our planet for the foreseeable future.’
Scientists at the Massachusetts Institute of Technology revealed in 2023 that an asteroid in that category will not impact Earth for at least the next 1,000 years.
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
