Last week, Earth was subjected to a rare event: not one, but two large asteroids passing at the same distance.
Neither 2024 MK nor 2011 UL21, as the asteroids are called, came close enough to pose a danger, but both were within range of radar imaging systems. So NASA got some happy photos to mark the occasion.
These are more than asteroid flyby souvenirs. Scientists can study the images to understand the properties of rocks that can be found near Earth—information that can help us strategize for any future asteroids that could one day threaten our planet.
Earth’s little corner of the solar system is almost empty, but not completely. A random comet or asteroid passes the Sun as it makes its own circular orbit around the Sun.
Most of them won’t be a problem. But anything that passes a certain distance from Earth or is above a certain brightness is classified as potentially dangerous.
This is because, although their current path may be fine, something unexpected could happen, such as a collision with another object that throws it on a collision course with Earth. Not likely, but not impossible either.
Both the 2024 MK and the 2011 UL21 were in the potentially hazardous category; fortunately for us, no unforeseen madness diverted them from their course in our direction.
2011 UL21 flew past Earth on June 27 at a distance of 6.6 million kilometers (4.1 million miles), about 17 times the distance between Earth and the Moon.
Then, less than two days later, 2024 MK appeared. On June 29, it flew a minimum distance of 295,000 kilometers (184,000 mi). That’s much closer, about three-quarters of the distance between the Earth and the Moon.
Imaging such objects is not entirely easy, even when they are relatively close and are classified as “large” asteroids. They are still quite small in the scheme of things and not very bright.
That’s why NASA uses a large radar telescope to transmit radio waves into space and receive the return signal from which scientists can construct images.
Because 2024 MK was much closer – such close proximity for an asteroid flyby only happens every few decades or so – we were able to get much more detailed images.
NASA used one telescope to transmit the radio waves and a second to receive them, resulting in images of 2024 MK that include not only the shape of the asteroid, but also bumps, bodies of water, boulders and ridges.
It measures approximately 150 meters (500 ft) across and is oblong in shape with many flat planes. It also flips as it moves through space.
It was only discovered on June 16, and its orbital path has been altered by Earth’s gravity, so the observations allow scientists to understand what 2024 MK will do in the future. They revealed that it will stay safely out of our way for the foreseeable future. ugh
“This was an outstanding opportunity to study the physical properties and obtain detailed images of a near-Earth asteroid,” said astronomer Lance Benner of NASA’s Jet Propulsion Laboratory.
2011 UL21, at a much greater distance, didn’t return images that were as detailed… but those images included a little surprise. There, accompanying the 1.5-kilometer-wide asteroid, astronomers spotted a small moon at an orbital distance of about 3 kilometers.
This is something that we are actually finding more and more with large asteroids.
Last year, the asteroid Dinkinesh, an object in the asteroid belt visited by NASA’s Lucy probe, was discovered to have a small moon. And NASA’s famous Double Asteroid Redirect Test, in which a spacecraft was smashed into an asteroid, was performed on Dimorphos, the smaller of the double asteroid pair.
We’re finding more binary asteroids because our imaging capabilities are improving, and that’s excellent news for protecting the planet and our understanding of the evolution of the Solar System.
“About two-thirds of asteroids of this size are thought to be binary systems,” says Benner, “and their discovery is particularly important because we can use measurements of their relative positions to estimate their relative orbits, masses, and densities. which provided key information about how they may have formed.”
And they are just so cute. Hello Friend. Fly anytime.
