Posted on by Bob King

Earth Dodges a Bullet — New Radar Images of Asteroid 2014 SC324

Goldstone delay-Doppler images of 2014 SC324 obtained on October 25. The images span an interval of about 45 minutes and show considerable rotation by this object, which has an irregular and elongated shape. Credit: NASA/JPL

Looks like we dodged a bullet. A bullet-shaped asteroid that is. The 70-meter Goldstone radar dish, part of NASA’s Deep Space Network, grabbed a collage of photos of Earth-approaching asteroid 2014 SC324 during its close flyby last Friday October 24. These are the first-ever photos of the space rock which was discovered September 30 this year by the Mt. Lemmon Survey. The level of detail is amazing considering that the object is only about 197 feet (60-meters) across.  You can also see how incredibly fast it’s rotating – about 30-45 minutes for a one spin.

A cropped version of the photo to more clearly see the asteroid's shape. 2014 SC324 passed just 1.5 lunar distances from Earth last week. Credit: NASA/JPL
A cropped version of the photo to more clearly see the asteroid’s shape. 2014 SC324 passed just 1.5 lunar distances from Earth last week. Credit: NASA/JPL

In the cropped version, the shape is somewhat clearer with the asteroid appearing some four times longer than wide. 2014 SC324 belongs to the Apollo asteroid class, named for 1862 Apollo discovered in 1932 by German astronomer Karl Reinmuth. Apollo asteroids follow orbits that occasionally cross that of Earth’s, making them a potential threat to our planet.  The famed February 15, 2013 Chelyabinsk fireball, with an approximate pre-atmospheric entry size of 59 feet (18-m), belonged to the Apollo class.

Three classes of asteroids that pass near Earth or cross its orbit are named for the first member discovered — Apollo, Aten and Amor. Apollo asteroids like 2014 SC324 routinely cross Earth’s orbit, Atens also cross but have different orbital characteristics and Amors cross Mars’ orbit but miss Earth’s. Credit: ESA
Three classes of asteroids that pass near Earth or cross its orbit are named for the first member discovered — Apollo, Aten and Amor. Apollo asteroids like 2014 SC324 routinely cross Earth’s orbit, Atens also cross but have different orbital characteristics and Amors cross Mars’ orbit but miss Earth’s. Credit: ESA

Lance Benner and colleagues at Goldstone also imaged another Apollo asteroid that passed through our neighborhood on October 19 called 2014 SM143. This larger object, estimated at around 650 feet (200-m) across, was discovered with the Pan-STARRS 1 telescope on Mt. Haleakala in Hawaii on September 17.  Tell me we’re not some shiny ball on a solar system-sized pool table where the players fortunately miss their shot … most of the time.