SECRETS OF THE SOLAR SYSTEM

摘要

Comets date back to when the planets formed 4.6 billion years ago. They preserve a record of the more volatile material that was available for planet creation, including water and other simple compounds such as ammonia, methane and carbon dioxide. They also contain organic molecules that would have been available as ingredients during the still mysterious event that sparked the origin of life on Earth. The thinking is that comets will be the Rosetta stones that will allow us to decipher the mysteries of the early solar system and our origins - hence the name of the mission. Rosetta will be the first spacecraft to orbit a comet and map its surface as the pair of them travel closer to the sun. It will also launch a robotic lander to analyse the comet's surface (see main story).