It looks like a giant bowling pin.
NASA’s New Horizons spacecraft has sent back its closest view of the most distant world humanity has ever visited, Ultima Thule, a snapshot taken on December 31. From half a million miles out, Ultima still appears fuzzy, but the irregularly-shaped object is becoming increasingly clear.
The day prior, New Year’s Eve, Ultima was just comprised of a few pixels — so this is a notable improvement.
“Even though it’s a pixelated blob still, it’s a better pixelated blob,” New Horizons project scientist Hal Weaver said Tuesday at mission headquarters, located at Maryland’s Johns Hopkins Applied Physics Laboratory.
Scientists estimate that Ultima is about 22 miles long by 9 miles wide (35 by 15 kilometers). It’s spinning through space — from our perspective — like a propeller blade, Weaver said.
New Horizons, however, has already successfully flown just 2,200 miles from Ultima’s surface, precisely at 12:33 a.m. ET on January 1, 2019. Data from these close-up images are now traveling through the solar system, so the fuzzy “blob” will get profoundly detailed over the coming days, revealing the surface of this distant world.
Scientists at New Horizons’ headquarters are abuzz: Successful mission updates, which show the craft is safe and operating well, have been met with roaring cheers and standing ovations.
And for good reason. Ultima lies in a far-off group of objects, called the Kuiper Belt, that ring the solar system. Temperatures here approach absolute zero (minus 460 degrees Fahrenheit), which is as cold as it gets. Scientists suspect that these ancient objects have been preserved in relatively pristine condition since the beginnings of the still-forming solar system, some 4 billion years ago.
Seeing Ultima, then, is like witnessing our solar system origins, long before the first life even evolved on Earth.
“The Kuiper Belt is just a scientific wonderland,” Alan Stern, principal investigator of the New Horizons mission, said on Sunday.
From the latest image, it still remains unclear if Ultima is actually two objects that are closely orbiting one another, or a single mass. But as of Tuesday morning, New Horizons scientists were betting on a single object.
“My money is on the single body,” said Weaver.
We’ll soon find out.