On New Year’s Day, NASA’s New Horizons probe streaked by a tiny world dubbed MU69, or Ultima Thule, the farthest object humankind has studied up close. With most of the data still on the spacecraft waiting to be transmitted, scientists are still getting to know this distant body. We know that it’s composed of two chunks of rock loosely stuck together. We know that it doesn’t have moons or rings that New Horizons might have careened into on its close pass. And we know Ultima Thule is red.
Carly Howett, a member of the New Horizons team, said that if you were standing on New Horizons as it sped past, Ultima Thule would appear red to the human eye and very dark. But with the aid of enhanced imagery, it’s also clear that some patches are redder than others, like the rim of the large crater known as Maryland.
That redness is likely caused by a mysterious class of compounds called tholins, the New Horizons team said Monday during a mission update at the 50th Lunar and Planetary Science Conference in Houston.
