The continent of Australia April 6, 2015. REUTERS/Scott Kelly/NASA

The Milky Way is seen September 28, 2014. REUTERS/NASA/Handout

Typhoon Maysak is seen as it strengthens into a Category 5 hurricane March 31, 2015. REUTERS/ESA/NASA/Samantha Cristoforetti/Handout

The big island of Hawaii February 28, 2015. REUTERS/NASA/ESA/Samantha Cristoforetti/Handout

Tropical Storm Bill in the Gulf of Mexico is seen approaching the coast of Texas in this picture from NASA astronaut Scott Kelly on the International Space Station taken June 15, 2015. REUTERS/NASA/Han

The continent of Australia April 6, 2015. REUTERS/Scott Kelly/NASA

The Milky Way is seen September 28, 2014. REUTERS/NASA/Handout

The Aurora is captured August 29, 2014. REUTERS/NASA/ESA/Alexander Gerst/Handout

ropical Storm Bill in the Gulf of Mexico is seen approaching the coast of Texas in this picture from NASA astronaut Scott Kelly on the International Space Station taken June 15, 2015. REUTERS/NASA/Han

North Korea and South Korea at night are seen in an undated picture. REUTERS/NASA/Handout via Reuters

The sun reflects off the water July 17, 2014. REUTERS/Alexander Gerst/NASA

Finger Lakes, New York, March 22, 2013. REUTERS/CSA/Col. Chris Hadfield

The Aurora Australis on an ascending pass west of Central America, September 18, 2011. REUTERS

The moon over layers of the Earth's atmosphere. REUTERS/NASA

The Nile and the Sinai Peninsula, March 20, 2013. REUTERS/CSA/Col. Chris Hadfield

Washington, D.C. with Andrews Air Force Base visible, March 22, 2013. REUTERS/CSA/Col. Chris Hadfield

An undated composite image shows the view taken from a mounted camera on the International Space Station. A total of 18 images were used to create the composite. REUTERS/NASA/Handout

Shiraz, Iran, March 20, 2013. REUTERS/CSA/Col. Chris Hadfield

Bushfires in Australia, January 2, 2013. REUTERS/Chris Hadfield/NASA

The space shuttle Endeavour is silhouetted against the backdrop of Earth's horizon prior to docking with the International Space Station, February 9, 2010. REUTERS/NASA

A large presence of stratocumulus clouds above the northwestern Pacific Ocean about 460 miles east of northern Honshu, Japan, January 4, 2013. REUTERS/NASA

Earth's airglow with an oblique view of the Mediterranean Sea area, including the Nile River with its delta and the Sinai Peninsula, October 15, 2011. REUTERS/NASA

Aurora Australis over the Indian Ocean, September 17, 2011. REUTERS/NASA

The India-Pakistan border appears as an orange line, August 21, 2011. REUTERS/NASA