Size and Distance. Apophis is about 1,100 feet (340 meters) in width. It’s expected to safely pass close to Earth β within 19,794 miles (31,860 kilometers) from our planet’s surface β on April 13, 2029. This will be the closest approach to Earth by an asteroid of this size that scientists have known about in advance.
Apophis is classified as an S-type, or stony-type asteroid made up of silicate (or rocky) materials and a mixture of metallic nickel and iron. Radar images suggest it is elongated and possibly has two lobes, making it look something like a peanut. Much more will be learned about this asteroid’s structure following its close flyby of Earth in 2029.
