By Padmaja Thirumalai
Staff Writer
Asteroids, what are they? According to space.com, they’re a rocky, metallic, or icy object that orbits around the sun and cannot be considered a planet. The concept of asteroids is fascinating, and it’s rare to witness a real asteroid orbiting Earth.
Recently, a mini-moon 2024-PT5 was discovered by a group called Asteroid Terrestrial Impact-Last Alert System (ATLAS). This moon entered Earth’s orbit on Sept. 29 and is expected to remain until Nov. 5.
Past mini-moons have indeed been reported to be “space junk.” But ATLAS has proven this mini-moon to be a real asteroid. The Earth’s gravitational pull caught this asteroid. Jacqueline McClearly, an assistant professor of Physics at Northern University explained how asteroids can be brought into the earth’s atmosphere.
“Perturbations – little kicks from Jupiter's gravity, the sun’s gravity, Earth’s gravity – can sometimes knock an object a little bit closer so that it falls in towards the Earth,” McCleary said in an interview with Northeastern Global News.
This temporary “fly-by” will not be visible to a human’s naked eye. According to CNET, the absolute magnitude of the 2024-PT5 is 27.593. This size is 300,000 times smaller than the real moon. The magnitude creates a dimmer asteroid, not allowing a person to view the moon with a normal telescope. Only a larger telescope would do the trick.
Mini-moons are not rare. They occur every year and some asteroids revisit Earth as well. According to CNET, the NXI asteroid from 2022 is meant to come back in 2051. It’s a constant phenomenon and researchers say they always revolve around the planet.
What do NASA scientists say? Unlike some other researchers, NASA scientists had an assumption that this asteroid was a chuck of rock ejected from the moon’s surface. But, from analyzing the asteroid's motion, their assumption was quickly ruled out. They also said that the asteroid won’t complete a full orbit and will depart from Earth instead. By 2055, the mini-moon will pass by again.
According to NBC, mini-moons are either short or long in size. Short mini-moons tend to last for hours or even months but they do not complete the full orbit. On the other hand, long mini-moons last for one year and they complete circling the entire orbit.
Scientists can also gain a lot of information from mini-moons. Scientists hope to learn the surface composition and the speed of rotation of the current mini-moon. This analysis will help in discovering the origin of this asteroid. The analysis will also help them in researching other asteroids that might visit Earth again. Based on their research, scientists will determine whether they are dangerous to our planet or not.
