Do you know that from September 29 to November 25, the moon won’t be the only celestial being （天體）that orbits （繞行）the earth? If you look up into the space using a high definition telescope（高畫質望遠鏡）, you will in fact see a mini moon, an asteroid named 2024 PT5. An asteroid（隕石） is a small rocky object that travels around the sun. After November 25, this mini moon will leave the earth‘s gravitational pull（地心引力） and fling back into the outer space. Even though we can’t see it with our naked eye since it’s only the size of a school bus, I personally think it’s so comforting to know that besides the moon, our planet will have a new companion for two months in this vast universe. And this asteroid will return to earth’s orbit again in 2025 and 2055. Scientists are interested in getting to know more about asteroids because they contain minerals （礦物質）and water that could be useful to humans in the future in our space exploration.