NASA Scientists Announce Earth Will Have a “Second Moon” This Sunday, But It Won’t Last Long.
“Second Moon” refers to asteroid 2024 PT5, which orbits the Sun as part of a small asteroid belt trailing Earth. This finding comes from a recent study published in the journal Research Notes of the AAS by experts Carlos de la Fuente Marcos and Raúl de la Fuente Marcos from Complutense University of Madrid, Spain.
Position of Earth, Sun, and Mercury on Sunday (September 29) when Earth has a “Second Moon.” (Photo: NASA/JPL).
The latest data from NASA’s Jet Propulsion Laboratory (JPL) Horizons system indicates that the appearance of the second moon will begin at 3:54 PM EDT (12:00 AM Hanoi time, September 29) and will end at midnight on November 25.
After a brief orbit around Earth, asteroid 2024 PT5 will continue its journey around the Sun as part of the Arjuna asteroid family.
2024 PT5 is not the first asteroid to be captured by Earth’s gravity to become a small moon. Scientists have recorded two previous instances, with one asteroid being captured for about a week, estimated to occur several times per decade. Longer captures, which are rarer, can last for years instead of weeks, allowing asteroids to complete one or more full orbits around Earth.
The fact that asteroid 2024 PT5 will only exist for a few weeks instead of billions of years is not the only major difference between this “small moon” and the actual Moon.
Even though this second moon will grace Earth’s night sky for at least half a month, 2024 PT5 will not be observable to the average skywatcher. However, professional astronomers are likely to capture images of this temporary appearance.
This is primarily due to the significant size difference between the two celestial bodies. While the Moon is estimated to have a diameter of 2,159 miles (3,475 km), 2024 PT5 is believed to be only about 10 meters wide. This means the Moon is over 308,108 times larger than the “moonlet” asteroid 2024 PT5.
“This object is too small and faint for ordinary telescopes and binoculars. However, it falls within the brightness range of telescopes typically used by professional astronomers,” concluded Professor Raúl de la Fuente Marcos. He advises users to employ a telescope with a diameter of at least 30 inches along with a CCD or CMOS detector for observation. “Using a 30-inch telescope and the naked eye will not suffice,” he stated.
