How Astronauts Shoot Night Photos of Home

By Norman Chan

The coolest photography rig off the planet.

A challenge that all astrophotographers face when taking photos of the night sky is the constant rotation of the planet. As Earth rotates at around 1000 miles per hour around its axis (at the equator), the stars above are moving ever so slightly as well, relative to where you're looking at them. And moving subjects make for blurry photographs, especially when shutter speeds have to be low to capture light at night. This is actually the same problem that astronauts aboard the International Space Station face when pointing cameras back down to Earth. Astronaut Chris Hadfield's amazing photos cities at night are possible not just because he's using a top of the line Nikon DSLR and 180mm zoom lens--that camera has to be stabilized in some way to compensate for the ISS travelling at a speed of 17,000 miles per hour. And a regular tripod just won't do.

Astronauts instead use something called a NightPod, a programmable motorized rig that helps astronaut photographers track subjects over long exposure times at night. It was installed by European Space Agency astronaut Andre Kuipers last February. The rig is fairly automatic--astronauts input the ISS's orbit and attitude/orientation, and the rig tracks a subject for as long as needs be to take the shot. The results speak for themselves: city lights and road traffic can be clearly seen in the photographs, where the width of one frame can span dozens of miles. The goal is to use NightPod imagery to study a multitude of scenarios, including urban pollution, volcano activity, and brush fires.

Of course, NightPod doesn't have to be pointed at Earth. NASA already has plans to use the rig to take better stellar photographs.