NASA's Mars rover Curiosity has for the first time used the camera on its arm to take photos at night, illuminated by white lights and ultraviolet lights on the instrument.

Scientists used the rover's Mars Hand Lens Imager (MAHLI) instrument for a close-up nighttime look at a rock target called "Sayunei," in an area where Curiosity's front-left wheel had scuffed the rock to provide fresh, dust-free materials to examine.

The site is near where the rover team plans to begin using Curiosity to drill into a rock in coming weeks. The images of the rock Sayunei and of MAHLI's calibration target were taken on Jan. 22 (PST) and received on Earth Jan. 23.

The MAHLI, an adjustable-focus color camera, includes its own LED (light-emitting diode) illumination sources. Images of Sayunei taken with white-LED illumination and with illumination by ultraviolet LEDs are available online here and here.

"The purpose of acquiring observations under ultraviolet illumination was to look for fluorescent minerals," said MAHLI Principal Investigator Ken Edgett of Malin Space Science Systems, San Diego.

"These data just arrived this morning. The science team is still assessing the observations. If something looked green, yellow, orange or red under the ultraviolet illumination, that'd be a more clear-cut indicator of fluorescence."