In an exciting astronomical event, Earth is set to gain a temporary “mini-moon” as a small asteroid is captured by our planet’s gravitational pull. Scientists report that this celestial visitor will arrive on September 29 and remain in orbit for approximately two months before escaping back into space.
The asteroid, designated 2024 PT5, was first detected by NASA’s Asteroid Terrestrial-Impact Last Alert System (ATLAS) on August 7. According to a study published in the Research Notes of the American Astronomical Society, the asteroid originates from the Arjuna asteroid belt, which contains rocks that travel in orbits similar to that of Earth. Occasionally, these asteroids come relatively close, with 2024 PT5 approaching within 2.8 million miles (4.5 million km) of our planet.
Dr. Jennifer Millard, an astronomer and host of the Awesome Astronomy podcast, explained, “If an asteroid like this is moving at a relatively slow speed of around 2,200 mph (3,540 km/h), Earth’s gravitational field can exert a strong influence, enough to trap it temporarily.” The asteroid is expected to enter orbit on September 29 and is projected to depart on November 25. However, it will not complete a full revolution around Earth; instead, its trajectory will be slightly altered by our planet’s gravity.
Measuring approximately 32 feet (10 meters) in length, 2024 PT5 is notably smaller than Earth’s moon, which has a diameter of about 3,474 km. Due to its small size and dull rock composition, it will be virtually invisible to the naked eye and will require professional telescopes for observation. “You’ll be able to look out for lots of wonderful pictures online of this little dot moving past the stars at great speed,” Dr. Millard added.
While mini-moons are rare, they have been observed before, with some making return visits. The asteroid 2022 NX1, for example, became a mini-moon in both 1981 and 2022. Researchers anticipate that 2024 PT5 will also return to Earth’s orbit in 2055.
“This story highlights just how busy our solar system is and how much there is out there that we haven’t discovered,” Dr. Millard noted. “There are tens of thousands, if not hundreds of thousands, of objects out there that we haven’t discovered, emphasizing the importance of monitoring the night sky.”
As excitement builds for this cosmic event, skywatchers are encouraged to stay informed for the latest images and updates on 2024 PT5’s journey through our solar system.
