The scientists learned much about the comet’s landscape. Dr. El-Maarry described its surface as very dark — reflecting just 3 to 4 percent of the sunlight that hits it. The darkness comes from a dearth of ice at the surface and an abundance of organic molecules.
Some areas are bare rock; others are smooth terrains buried in dust. “You can think of something like a sea of sand being surrounded by cliffs,” Dr. El-Maarry said.
The rocks are cracked with fissures.
“Anywhere we can see that surface and we have good enough resolution, we see fractures everywhere,” Dr. El-Maarry said.
— Kenneth Chang, Rosetta Mission Ends With Spacecraft’s Dive Into Comet
This description is both lonely and beautiful. Imagine that dark desert, framed with broken cliffs, hurtling through the black of space.