On Feb. 10, asteroid 2006 DP14 zipped by Earth at six times the distance of the moon or 1.5 million miles (2.4 million km). One night later, astronomers used the 230-foot (70-meter) Deep Space Network radar antenna at Goldstone, Calif. to beam radio waves at the fleeing space rock and “take pictures” of it by measuring the returning radio echoes. At the time, the asteroid had receded to 11 times the moon’s distance.
Imagine their pleasant surprise when they discovered it was shaped like a giant space peanut.1,300 feet (400 m) long by 660 feet (200 m) wide. By the way, the headline refers to a famous rhyme by Andre the Giant in the movie The Princess Bride.
Radar movie shows asteroid 2006 DP14 rotating. The images were gathered over 2.5 hours and shows details as small as 60 feet across
Each lobe was probably a separate asteroid at one time. Circumstances allowed them to migrate toward one another through their mutual gravitational attraction, creating what astronomers call a “contact binary”. Ten percent of near-Earth asteroids larger than about 650 feet (200 m) have contact binary shapes. This tells us that there were times and places in the solar system (and may still be) where asteroids moved slowly enough relative to one another to join together. Just a hunch, but maybe it happened routinely in the solar system’s youth, helping to build the planets and larger asteroids.
As a little experiment to show the 2006 DP14’s topography and peanut shape more clearly, I apply a blur filter in Photoshop to the original image.
While this sounds counterintuitive, blurring removes the confusing pixelation and lets us see the essentials more clearly. At least to my eye. What do you think?
Radar is the best technique yet for resolving asteroid shapes, surface details and rotation rates. It can also pinpoint a space rock’s position with great precision, improving the accuracy of asteroid orbit calculations much farther into the future. This is critical to determining if a near-Earth object might become a collision threat or if will safely miss our planet.