A is a ‘dirty snowball†of ice and rocky debris, typically a few miles across, that orbits the Sun in a long ellipse. When close to the Sun, the warmth evaporates the ice in the nucleus to form a coma (cloud of gas) and a tail. Named for their discoverers, comets sometimes make return visits after as little as a few years or as long as tens of thousands of years.
Mars Express achieves 25,000 orbits
Mars Express achieves 25,000 orbits by Erica Marchand Paris, France (SPX) Mar 28, 2024 Celebrating a significant milestone, ESA's Mars...