I am going to factcheck this claim using the SIFT method.
This claim was posted by an anonymous user claiming that Earth will get a second, “mini”, moon citing an article by CBS News which is a long standing news company with a slightly left lean. Upon reading the article they state that Earth will be getting a second “moon” starting on September 29th 2024 and ending November 25th 2024. The asteroid, dubbed 2024 PT5 by the Asteroid Terrestrial-impact Last Alert System, an asteroid monitoring system funded by NASA who initially spotted the asteroid, will orbit the earth in a horseshoe shape for two months, then get pulled back into space. To check the claim, I found multiple articles published by space.com, National Geographic, and phys.org which restated the same things CBS reported on. While this anonymous claim was relatively correct, there is a slight caveat. This moon is only here for 2 months, so it isn’t a permanent change to anything which isn’t how the original poster made it sound. National Geographic interviewed Thomas Statler, the lead scientist for solar system small bodies at NASA who said that; “To become a second moon, the asteroid would have to be gravitationally bound to our existing Earth-Moon system and make multiple circuits around it. These conditions currently don’t apply to the asteroid, which was recently dubbed 2024 PT5.” So while this claim isn’t exactly incorrect, it is slightly misleading and overexaggerated. Nevertheless, this is a super cool and unique thing for us to be experiencing!