NASA's Mars Exploration Rover Opportunity has been exploring the Red Planet for more than a decade, and just last year set a new record for traveling farther than any other off-world rover in history.
The rover has driven more than 25 miles on the surface of Mars and during its travels it has taken countless selfies and panoramas, but perhaps the most stunning images in its collection are of this blue Martian sunset, which NASA has compiled into this stunning movie, shown in the Vine below.
Opportunity has been exploring a region near Mars' equator, where an average temperature on a summer day can reach up to 70 degrees Fahrenheit. Not bad for a planet more than 140 million miles from the sun. However, without any clouds and only a thin atmosphere to help insulate the planet, after the sun sets, Mars temperatures readily drop to minus 100 degrees Fahrenheit.
And the blue sun in the stunning sunset above is a chilling reminder of the cold temperatures that will follow. The reason that Mars' sky appears red during the day and ignites with a brilliant blue during sunset is because of the red dust drifting through the thin atmosphere.
"The blue color comes from the way Mars' dust scatters light. The blue light is scattered less, and so it stays near the sun in the sky, while red and green are all over the sky," said Mark Lemmon, an associate professor of planetary sciences at Texas A&M University, in a university state mtn. "On Earth, blue light is scattered all over by gas molecules, but there are not enough of these on Mars, which has less than 1 percent of Earth's atmosphere, to accomplish this."
Check out this 50-second video of the Martian sunset: