NASA astronaut Terry Virts posted this image to Twitter on April 13, 2015 with the text, "Remnants of #Joalane still churning away in the moonlit Southern Indian Ocean, with the Milky Way rising behind it."

NASA astronaut Terry Virts routes cables during a spacewalk on the International Space Station as the sun begins to peak over the Earth's horizon, on Feb. 21 2015.

Nasa Astronauts posted this image to twitter, Feb. 23, 2015, with the caption, "#London eyes #Paris across the channel, with #Brussels peering in" #AstroButch"

Astronaut Barry "Butch" Wilmore posted this photo on Twitter on Feb. 9, 2015, with the caption "Spiral of lights BURSTING from Earth! Spain looks like it is floating away from Africa."

Italian astronaut Sam Cristoforetti posted this photo on Feb. 2, 2015, from aboard the International Space Station, with the caption "??The Gulf of St. Lawrence has become one of my favorite places. Look at these amazing cloud patterns!"

Italian astronaut Sam Cristoforetti posted a photo on Twitter on Jan. 17, 2015, with the caption "And a look from above into the eye of the cyclone!" The image, taken from the International Space Station, shows lightning in the center of Cyclone Bansi.

NASA Astronaut Barry E. Wilmore captured this picture of Italy at night from aboard the International Space Station and posted it on Twitter on Jan. 4, 2015 with the caption "Italy and Aegean Sea in the distance ... a night to remember!"

NASA Astronaut Barry E. Wilmore captured this picture of the Nile River Valley at night from aboard the International Space Station and posted it on Twitter on Jan. 4, 2015 with the caption "A sparkling Nile river valley and delta Egypt … fabulous!"

Astronaut Reid Wiseman posted this photo to Twitter on Sept. 2, 2014 from the International Space Station with the caption, "My favorite views from #space just past #sunrise over the ocean."

Astronaut Alexander Gerst posted this photo to Facebook from the International Space Station on July 29, 2014 with the caption, "Probably a river in Kazakhstan or slightly west of it."

Astronaut Alexander Gerst posted this photo to Facebook from the International Space Station on Aug. 19, 2014 with the caption, "I believe this is where Pacman was invented. Irrigation in the Mid-Western USA."

Astronaut Alexander Gerst posted this photo to Facebook on Aug. 30, 2014 from the International Space Station with the caption, "Wolkenwirbel", which means "cloud vortex" in German.

Astronaut Reid Wiseman posted this photo to Twitter on Aug. 23, 2014 from the International Space Station with the caption, "Cool eddies off the coast of #England in the late afternoon. #EarthArt".

Astronaut Reid Wiseman posted this photo to Twitter on Aug. 8, 2014 from the International Space Station with the caption, "#EarthArt - Australia style."

Astronaut Reid Wiseman posted this photo to Twitter on Aug. 29, 2014 with the caption, "We just got a new 800mm lens, it'll be a great weekend. #EarthArt, the sands of Africa".

Astronaut Reid Wiseman posted this photo to Twitter on Aug. 6, 2014 from the International Space Station with the caption, "Gorgeous view of #Chicago and #Detroit around 3am on Wednesday morning."

Astronaut Alexander Gerst posted this photo to Facebook from the International Space Station on July 9, 2014 with the caption, "Land use in South Africa - you can see where water is available."

Astronaut Alexander Gerst posted this photo to Facebook from the International Space Station on Aug. 19, 2014 with the caption, "Oil fields near Midland, Texas."

Astronaut Alexander Gerst posted this photo to Facebook on Aug. 16, 2014 from the International Space Station with the caption, "Looking for rain clouds in the Sahara Desert, this is all you get #BlueDot".

Astronaut Reid Wiseman posted this photo to Twitter on Aug. 9, 2014 from the International Space Station with the caption, "Houston all the way to Galveston at 4am."

Astronaut Reid Wiseman posted this photo to Twitter on Aug. 16, 2014 from the International Space Station with the caption, "Hold on @BradPaisley, we don't usually like leaks at the launch pad ;) Here is Florida from the space station."

Astronaut Reid Wiseman posted this photo to Twitter on Aug. 16, 2014 from the International Space Station with the caption, "Unreal #EarthArt not clouds. These spirals are Pacific Ocean currents in sun glint."

Astronaut Alexander Gerst posted this photo from the International Space Station to Facebook on June 25, 2014 with the caption, "I like this view of Buenos Aires. Can you spot the airport?"

Astronaut Alexander Gerst posted this photo to Facebook from the International Space Station on Aug. 18, 2014 with the caption, "Picturesque, but only a tiny display of cosmic destruction power. (Barringer Crater, USA)"

Astronaut Alexander Gerst posted this photo to Facebook from the International Space Station on July 27, 2014 with the caption, "Irrigation in the Sahara Desert looks like a challenging task from up here..."

Astronaut Alexander Gerst posted this photo to Facebook from the International Space Station on Aug. 27, 2014 with the caption, "Floods in northern India".

Astronaut Alexander Gerst posted this photo to Facebook on Sept. 3, 2014 from the International Space Station with the caption, "Quite excited, I get to "phone home" tomorrow, to my hometown, Kunzelsau."

Astronaut Reid Wiseman posted this photo to Twitter on Aug. 7, 2014 from the International Space Station with the caption, "A nice after dinner view of the snowcapped Andes looking northwest."