Topline
An asteroid the size of a building will pass close by Earth later tonight, though experts say it doesnât pose any threat to the planet.
Key Facts
A 250-foot asteroid will pass by Earth on Friday, coming within 4.1 million miles of the planetâabout 17 times further than the Moonâwhile traveling about 26,719 miles per hour, according to NASAâs California-based Jet Propulsion Laboratory.
NASA classifies all asteroids that come within 4.6 million miles of Earth, and are larger than 492.126 feet (150 meters) as a âpotentially hazardous object,â so although this asteroid is expected to make a close approach, it doesnât meet the size requirement to be deemed potentially hazardous, and âposes no hazard to our planet,â a JPL official told Forbes.
The last time this asteroid, called 2024 CJ8, passed by Earth was in 2020, and the next time will be on Aug. 29, 2028, though this yearâs approach is the closest itâs ever been to Earth, according to NASAâs estimates.
Itâs expected to pass by Earth at 8:25 p.m. EDT, and although it wonât be visible to the naked eye, NASA offers a virtual asteroid tracker to watch where in the solar system asteroids are in real time.
Big Number
More than 1.3 million. Thatâs how many asteroids NASA estimates are in the solar system.
Key Background
Asteroids are rocky objects made up of the leftover remains from when the solar system was formed about 4.6 billion years ago, according to NASA. Theyâre smaller than planets, but orbit the Sun like planets do. In more recent years, NASA has upped its efforts to protect Earth from coming into contact with asteroids. The agency performed its first Double Asteroid Deflection Test in 2022, which changed the orbit of an asteroid. It sent a spacecraft into space, which hit the asteroid and shortened its orbit by a little over 30 minutes. In another effort to defend against potential asteroid approaches, NASA also sent a spacecraft on the mission OSIRIS-REx, which explored a large near-Earth asteroid named Bennu. The spacecraft collected samples from Bennu and dropped them off in the Utah desert in September 2023, and the findings suggest Bennu may be a fragment of an ancient ocean world. More research is being done on Bennu because scientists think it may collide with Earth in 2182. Though the exact area is unknown, Bennu has a one-in-2,700 chance of hitting a Texas-sized portion of Earth in 2182.
Surprising Fact
The spacecraft that was a part of OSIRIS-Rex is now on a new mission called OSIRIS-APEX, in which it will study the physical changes of another asteroid named Apophis. The spacecraft wonât return until 2029.
Tangent
Asteroid 2024 CJ8 wonât be the only one passing by Earth this weekend. It will be accompanied by the much smaller asteroid 2024 EQ, which is 69 feet wide, making it the size of an airplane. Itâs expected to come within an even closer approach to Earth, reaching about 1.65 million miles of the planet. Asteroid 2024 EK4 is also expected to pass by Earth this weekend. The bus-size asteroid is 32 feet wide, and is predicted to come within 2.5 million miles of Earth.
Further Reading
NASA scientists calculated the exact date an asteroid could hit Earth with the force of at least 24 nuclear bombs. Thankfully, it’s a long way off. (Business Insider)
Next Five Asteroid Approaches (Jet Propulsion Laboratory)