Relatively speaking, exposed ice is in limited quantities.
Researchers used Rosettas VIRTIS infrared tool to study the comets top layer and determine its composition.
This is the result of fast condensation over each comet rotation of just over 12 hours.
They likely formed slowly over time and are only occasionally exposed through erosion, said Gianrico.
Earlier this week, the researchers announced the imminent demise of Rosettas lander, Philae.
However, scientists have now had to declare the Philae lander dead after failing to revive the lander.
source: www.techworm.net
