Spectacular image captures International Space Station crossing in front of the sun during astronaut spacewalk

Astronauts were performing a spacewalk outside of the International Space Station as it passed in front of the sun last week — and a NASA photographer captured the exact moment it happened. The resulting image is breathtaking. 

A composite image made from seven frames taken by NASA photographer Joel Kowsky shows the silhouette of the ISS last week as it transited the sun at about five miles per second, or about 18,000 miles per hour. The images, which feature the sun as a glowing orange backdrop to the orbiting laboratory, were taken from Nellysford, Virginia, NASA said in a statement Monday. "This was a fun one to chase down today," Kowsky tweeted after snapping the rare photos.