The Very Special Christmas ‘Hippo’ Asteroid Is Set To Fly Past Earth On Its Closest Approach In 400 Years


If you look up at the sky on Saturday, December 22, you will be warmly greeted by the sight of asteroid 2003 SD220, also referred to as the “hippo” asteroid, and the approach of this asteroid will mark the closest it has been to Earth in 400 years. It won’t be this near to us again until 2070, so this Christmas asteroid is not one to be missed.

As Space report, the last time asteroid 2003 SD200 approached Earth during the holiday season was in 2015, but it wasn’t quite as close as it will be this year. According to a Twitter post from NASA’s Jet Propulsion Laboratory, the asteroid will be just 1.8 million miles away from Earth and, while still at a comfortable distance, will be viewable to Earthlings below it.

“Do you want a hippopotamus for Christmas? You’re in luck. Hippo-shaped #asteroid 2003 SD220 will fly safely past Earth on Saturday, Dec. 22, at a distance of ~1.8 million miles (~2.9 million km).”

This Christmas asteroid has been referred to as the hippo asteroid as radar images of the massive piece of space rock do make it look like a vast hippopotamus floating in space, or, as NASA have stated, “similar to that of the exposed portion of a hippopotamus wading in a river,” albeit a hippopotamus that stretches for an entire mile.

The stunning radar images of the Christmas hippo asteroid were snapped on December 15 and December 17 by scientists working at various locations, which include the National Science Foundation’s Green Bank Telescope in West Virginia, Arecibo Observatory in Puerto Rico, NASA’s Jet Propulsion Laboratory in Pasadena and the Goldstone antenna in California.

To attain these images, instruments from Goldstone and Arecibo used microwave signals that could be bounced off asteroid 2003 SD220, after which the Green Bank Telescope was then able to come up with extremely detailed images of the hippo asteroid’s very unique shape, as well as its size.

As Lance Benner of JPL explained, “The radar images achieve an unprecedented level of detail and are comparable to those obtained from a spacecraft flyby. The most conspicuous surface feature is a prominent ridge that appears to wrap partway around the asteroid near one end.”

The last observations of the hippo asteroid that were taken were in 2015, and thanks to new technology, this time around the details are 20 times clearer and more detailed than they were three years ago.

Because of both its size and its close proximity to Earth, NASA have asteroid 2003 SD220 on their watch list, but on this particular approach there is nothing to worry about and NASA have stated that there is absolutely no impact risk whatsoever to our planet when the hippo asteroid flies past us on December 22.