Northern Spring on Mars

Astronomical spring came to planet Earth's northern hemisphere this week (and autumn to the
south) with the equinox on March 20th. But on Mars, northern spring began on January 22nd. Still in
northern springtime, the Red Planet currently has a similar appearance to this composite of images
from previous years taken by the long-lasting Mars Global Surveyor spacecraft. The sprawling dark
region near picture center is Syrtis Major, with the whitish Hellas impact basin just below, in the
southern hemisphere. The four seasons on Earth each last about 90 earth days, while Mars' larger and
more eccentric elliptical orbit results in seasons that are longer and vary more widely in length -
from about 140 to 190 martian sols.