'ASTEROID'S 'CLOSEST FLYBY' 400 YEARS

IF ONLY a hippopotamus will do this Christmas, Santa has the space rock for you.

A small asteroid flew safely by Earth last Saturday, [Dec 22] according to the folks at NASA. And it looks just like the mighty hippo in new radar images.

The asteroid, called 2003 SD220, is also making its closest approach to Earth in more than 400 years and won't be any closer until 2070, NASA officials said.

It last flew by Earth on Christams Eve of 2015.

''Do you want a hippopotamus for Christmas?'' officials with NASA Jet Propulsion Laboratory wrote on Twitter last Friday. ''You're in luck. Hippo-shaped asteroid 2003 SD220 flew safely past Earth on Saturday, 22, at a distance of 1.8 million miles [2.9 million kilometers] .

The new radar images revealed that that asteroid 2003 SD220 is nearly a mile long [1.6 kilometers]  and has a shape to that of the exposed portion of a hippopotamus wading in a river.'' JPL officials said in a statement.

The asteroids size and close flybys of Earth  make it potentially hazardous asteroid to watch for NASA, but it poses no impact threat to our planet, agency officials said.

The radar images were taken between Dec 15 and Dec 17 by scientists with NASA's JPL, Golodstone antenna in California, Arecibo Observatory in Puerto Rico and the  National Science Foundation's Green Bank Telescope in West Virginia.

The Gladstone and Arecibo instruments bounced microwave signals off the asteroid that were then picked up by the Green Bank Telescope to create detailed radar images of the rock's size and shape.

The new images also confirm key details about asteroid 2003 SD220, NASA added.

They show that the asteroid rotates just once every 12 days - an oddly slow spin for a space rock. It also has a wobbly motion that NASA officlals likened a badly thrown football [or perhaps meandering hippo?']

''Known as 'non-principal axis' rotation, it is uncommon among near-Earth asteroids, most of which spin about their shortest axis,'' NASA officials said about of the asteroids motion.

By refining asteroid 2003 SD220s rotation, size and shape, the new radar images will help scientists understand how it formed and evolved over time, researchers said.

The observations were funded by NASA's Near-Earth Object. Observations Program, which regularly tracks potentially dangerous asteroids for the Planetary Defense Coordination Office that oversees the Agency's Planetary Defense Program.