The Mars Phoenix Lander has a lidar used in meteorological research of Martian weather. A lidar is basically a radar which uses lasers instead of radio waves. It is used to study particles floating around the Martian atmosphere. It also gives an unintentional laser light show. While it’s pretty bare-bones, it’s somewhat awe-inspiring in that it’s millions of kilometers away on another planet.
In other news, the lander has been able to get a tiny bit of water in the dirt sample that had previously been stuck on the scoop (apparently not all of the water ice sublimated away during the delay) and the Phoenix mission has been extended by 30 days, which gives extra time to fully utilize all of the ovens in the TEGA instrument and allows more extended observations of the weather changes near the Martian north pole. And there is also the good news that they won’t have to worry about a possible short circuit dooming the mission as long as they don’t overheat the instruments.