Mars Rover Snaps Rare Night Photo with LED Lights

A Mars rover just turned into a nighttime photographer, lighting up the dark Martian surface with nothing more than the equivalent of a few dinner candles.

NASA's Curiosity rover captured its first nighttime photo on December 6, using tiny LED lights normally reserved for peeking into shadowy drill holes during the day. The rover's camera team wanted a closer look at a particularly smooth drill hole and decided to schedule a nighttime photoshoot on the Red Planet.

The image required a five-second exposure, making it about 300 times dimmer than a typical Martian daytime shot. That's equivalent to shooting in conditions eight or nine stops darker than normal, according to Tex Kubacki, who leads camera operations for Curiosity's Mastcam.

What makes this photo special goes beyond its rarity. The white LED lights actually produce more accurate colors than daytime photography on Mars. Sunlight on Mars has a reddish tint from all the dust in the atmosphere, which affects how scientists see the true colors of rocks and soil.

The rover's camera setup is simpler than what you'd find in a basic DSLR. It has a fixed aperture at f/10, no mechanical shutter, and essentially operates at ISO 100 with only exposure time as a variable. The team took multiple shots at different exposure times just to make sure they got a good image.

Those LEDs aren't powerful by Earth standards. Each of the four white lights puts out just 450 to 715 millicandelas, less than a single candle and much dimmer than a standard flashlight. But in the pitch darkness of a Martian night, they're enough to illuminate the drill hole and surrounding surface.

The drilling method itself prompted this creative photography session. Curiosity's team recently changed how the rover drills into Mars, and the new technique usually creates rough, dusty holes that are hard to analyze visually. When they drilled into a rock nicknamed "Nevado Sajama" on November 13 and found surprisingly smooth walls, they saw an opportunity.

The Bright Side

This nighttime experiment shows how NASA scientists keep finding creative ways to squeeze more discoveries out of a rover that's been exploring Mars for over 4,700 Martian days. By thinking outside the box about when and how to use their tools, they're getting clearer, more accurate data about Mars than ever before.

Curiosity continues to surprise us with its imaging achievements, from beautiful day-night postcards to portraits of Earth as seen from Mars. Now it's adding nighttime photography to its resume, proving that even after years on the Red Planet, there are still new ways to see our neighboring world.