Happy Anniversaries, Spirit and Opportunity

Just to point out that January marks two anniversaries for some of the most captivating extraterrestrial exploration performed in the last couple decades, Space.com reminds us that the Mars rovers Spirit and Opportunity each celebrate the turn of their 4th years on the red planet this month:

Two robots the size of golf carts were given 90 days to squeeze as much science as possible from the barren, dust-swept terrain of Mars. After that, scientists expected nothing more from them than death.

Nearly four years after their warranties expired, however, the Mars
Explorations Rovers (MERs) "Spirit" and "Opportunity" continue to play productively in the red dirt.

Spirit celebrates its fourth anniversary of Martian work on Jan. 4, the day it landed in 2004, followed by Opportunity on Jan. 25. Those four Earth years since landing convert to 2.25
Martian years, or 1,422 Martian days called "sols."

I have to guess that many of us have desktop wallpapers made from the images sent back by these two workhorse robots. The success of these projects in expanding our vision of our solar system cannot be overstated. Bravo to all involved! Link to the story, via Slashdot.

Link to JPL Mars Rovers website.