Red it is! NASA’s New Horizons mission, which flew past Pluto last July, is on its way to another asteroid that bears a colorful resemblance to the dwarf planet.
Observations made with the Hubble Space Telescope suggest that 2014 MU69, a small icy asteroid in the Kuiper Belt about a billion miles (1.6 billion km) beyond Pluto, is as red, if not redder, than Pluto. Of course, Pluto isn’t actually red the way we think of red. It’s more pink or brown, colors caused when hydrocarbon molecules such as methane in its atmosphere react with the ultraviolet part of sunlight to create more complex molecules called tholins that have a reddish-brown appearance. These drift down to the surface and “paint” the surface red.
What’s exciting about the news is that this is our first hint of the surface properties of this remote object which New Horizons will survey during a flyby on Jan. 1, 2019. We are only beginning to know this new target, estimated at 27 miles (45 km) across, and so far away that it orbits the sun once every 293 years.
In other Pluto news, the New Horizons mission team has spied a handful of potential clouds in images taken with probe’s cameras. “If there are clouds, it would mean the weather on Pluto is even more complex than we imagined,” said Alan Stern, principal investigator for the mission.
Scientists already knew from telescope observations that Pluto’s icy surface below that atmosphere varied widely in brightness. Data from the flyby not only confirms that, it also shows the brightest areas (such as sections of Pluto’s large heart-shaped region) are among the most reflective in the solar system. And brightness, which equals freshness, indicates surface activity.
While Pluto shows many kinds of activity, one surface process apparently missing is landslides. Surprisingly, though, they’ve been spotted on Pluto’s largest moon, Charon, itself some 750 miles (1,200 km) across. “We’ve seen similar landslides on other rocky and icy planets, such as Mars and Saturn’s moon Iapetus, but these are the first landslides we’ve seen this far from the sun,” said Ross Beyer, a science team researcher from Sagan Center at the SETI Institute and NASA Ames Research Center, Moffett Field, California.
Once again, being small, bitter cold and far from the sun doesn’t preclude more activity that anyone could have expected.