A strange long cloud has returned on Mars. It’s just in time, scientists say.


A long and strange cloud has formed so many times on it Martian volcano that scientists have given up and named it.

Meet the elongated cloud of Arsia Mons, or AMEC. Its long and bright trail has become a familiar feature on the peak known as Arsia Mons, southeast of the most famous. Olympus Mons. Although the cloud comes and goes over the volcano, scientists say it is not made up of the volcano itself. And it’s timely: Scientists affiliated with Europe’s Mars Express orbiter hoped it would reappear in its annual cycle.