Just call it an interplanetary postcard.

On May 5,My Sister in law Reluctantly Climbed on Top NASA launched two, tiny, briefcase-sized satellites (called cubesats) to Mars, but at least one of them still has an eye for Earth. One of the Mars Cube One (MarCO) cubesats, nicknamed Wall-E, snapped a photo of Earth from more than half a million miles away.

SEE ALSO: Tiny satellites named Wall-E and Eva are about to take a trip to Mars. Will they survive?

Earth appears as a pale blue speck, and to its left is an even fainter speck: our moon.

NASA scientists weren't doing this for sport, but to see if the cubesat's antenna had unfolded -- and worked.

Original image replaced with Mashable logoOriginal image has been replaced. Credit: Mashable

The cubesats are following NASA's InSight lander to the red planet.

NASA wants to see if these small satellites can relay information from the lander -- a car-sized spacecraft that will study Mars' geology -- back to Earth as the probe lands on the Martian surface.

Mashable Light Speed Want more out-of-this world tech, space and science stories? Sign up for Mashable's weekly Light Speed newsletter. By clicking Sign Me Up, you confirm you are 16+ and agree to our Terms of Use and Privacy Policy. Thanks for signing up!

For NASA scientists, Earth's appearance as just a minuscule blue dot was reminiscent of an image the Voyager spacecraft sent back to Earth in 1990, from several billion miles away.

Original image replaced with Mashable logoOriginal image has been replaced. Credit: Mashable

"Consider it our homage to Voyager," Andy Klesh, Mars Cube One's chief engineer said in a statement.

"Cubesats have never gone this far into space before, so it's a big milestone," Klesh added. "Both our Cubesats are healthy and functioning properly. We're looking forward to seeing them travel even farther."

The cubesats -- formally called MarCO-A and MarCO-B -- have a ways to go.

They'll be subjected to the intense cold and radiation of deep space for six months, and it's unknown if the miniaturized satellites will be able to bear the extreme conditions.

Original image replaced with Mashable logoOriginal image has been replaced. Credit: Mashable

If they do make it to Mars and successfully relay information back to Earth, they will have demonstrated that perhaps small satellites may have a place in deep space as a part of a NASA mission after all.

Rather than building and launching bulky satellites into space, these small, cheaper spacecraft can accompany missions to land on other planets and moons, making hugely expensive space exploration considerably more affordable.

The two Mars Cube One satellites and InSight should arrive at Mars in November.


Featured Video For You
It takes absolute precision to construct Earth's largest telescope, which will peak into far-off alien worlds