2 massive asteroids to go close to Earth
Two asteroids will safely go our planet this week, and each are massive sufficient to identify in small telescopes. In an astronomical coincidence, they’ll seem finest on the identical evening, June 28. Asteroid 2011 UL21 is likely one of the largest near-Earth asteroids seen in beginner telescopes this yr, at 1.4 miles (2.3 km) extensive. That makes it bigger than 99% of all recognized near-Earth objects. Nevertheless, it’s going to go at a protected distance of 4,122,350 miles (6,634,279 km) from Earth’s floor, or about 17 occasions farther than the moon on June 27.
The opposite asteroid, newly found 2024 MK, is a bit smaller, between 400 and 840 toes (122 and 256 m) in diameter. However it’s going to go nearer to us than the moon on June 29.
No, there’s completely no hazard from any of the asteroids passing this week, or from any recognized space rock up to now.

Asteroid 2011 UL21
Asteroid 2011 UL21 is a big space rock. As you might need guessed from its identify, we’ve recognized about it since 2011. Scientists found it in October 2011 from the Catalina Sky Survey in Tucson, Arizona. Nevertheless, this shall be its closest method in its orbit since its discovery. Asteroid 2011 UL21 will go closest to our planet on June 27 round 4:16 p.m. EDT (20:16 UTC).
But when it’s cloudy on June 27, by no means concern. Asteroid 2011 UL21 shall be simply observable in small telescopes from June 27 to 30. The truth is, it seems brightest on Friday, June 28. Then, in 65 years, the big space rock will return even nearer to Earth on June 25, 2089.
The truth is, as a consequence of its massive dimension and superb velocity of 57,937 miles per hour (or 25.9 km per second) relative to Earth, you’ll simply be capable of detect the asteroid’s movement towards the celebs in telescopes of 6-to-8 inches and bigger.
Star charts for asteroid 2011 UL21
And, though each space rocks shall be simply seen in small telescopes, they won’t be vivid sufficient so that you can spot them with the unaided eye. Listed below are finder charts for asteroid 2011 UL21, which shall be passing by Virgo.


Asteroid 2024 MK
Whereas it’s taken years from asteroid 2011 UL21’s discovery to its closest flyby, asteroid 2024 MK is one other story. Scientists found 2024 MK on June 16, 2024, with ATLAS-Sutherland in South Africa. And now, only a couple weeks later, it’s making its closest go to Earth. Asteroid 2024 MK will go Earth at about 77% the Earth-moon distance. And whereas it’s a lot smaller than 2011 UL21, a rock this dimension would nonetheless do appreciable harm if it struck Earth. For comparability, the space rock that disintegrated over Chelyabinsk in Russia in 2013 was about 1/5 to 1/10 of the scale of 2024 MK.
Closest method of asteroid 2024 MK happens on June 29, 2024, at 9:50 am EDT (13:50 UTC). Nevertheless, the asteroid seems brightest on Friday, June 28. Coincidentally, it’s the identical evening as 2011 UL21 seems brightest.
One caveat: Asteroid 2011 UL21 shall be nicely positioned within the sky for observers within the U.S. and for observers in mid north latitudes, in addition to for observers within the Southern Hemisphere. Nevertheless, asteroid 2024 MK shall be low within the south route throughout closest method. Thus, this second asteroid (2024 MK) shall be finest for observers within the southern U.S., in addition to in Central America, the Caribbean, South America and the Southern Hemisphere typically.
Asteroid 2024 MK shall be greater within the sky on the subsequent evening (June 29) for observers in all U.S. It should nonetheless be observable in small telescopes, simply considerably fainter than June 28.
Finder charts for 2024 MK
Listed below are finder charts for 2024 MK for June 28.


And listed here are finder charts for 2024 MK for June 29.


Skilled astronomers will monitor the two massive asteroids
NASA’s Goldstone radar in California will observe asteroid 2011 UL21 from June 26 to July 3, 2024. Total, scientists have discovered that about 2/3 of near-Earth asteroids this huge with rotation intervals of lower than three hours are binary methods. So there’s an excellent likelihood 2011 UL21 has a companion, or asteroid moon, which is perhaps revealed throughout this go.
The Minor Planet Middle has labeled 2011 UL21 as a Potentially Hazardous Asteroid as a consequence of its massive dimension and nearness to Earth.
In the meantime, radar observations for asteroid 2024 MK (additionally designated as a Doubtlessly Hazardous Asteroid) will happen on June 30, July 1 and July 2.
Backside line: Two massive asteroids will safely go Earth this week. Search for them from June 27 to 30 with a telescope.



