The Dynamic Albedo of Neutrons (DAN) instrument is an experiment mounted on the Mars Science Laboratory's Curiosity rover.

It is a pulsed sealed-tube neutron source and detector used to measure hydrogen or ice and water at or near the Martian surface.

DAN was provided by the Russian Federal Space Agency,[1][2] funded by Russia[3] and is under the leadership of Principal Investigator Igor Mitrofanov.

[7] On August 19, 2015, NASA scientists reported that the DAN instrument on Curiosity detected an unusual hydrogen-rich area, at "Marias Pass," on Mars.

The hydrogen found seemed related to water or hydroxyl ions in rocks within three feet beneath the rover, according to the scientists.