Midnight Sun on Mars by Phoenix

Phoenix is still working hard on the surface of Mars, scraping and digging into the frozen regolith, preparing samples for the next TEGA bake. This next sample to be dropped into one of the eight on board ovens will intensify the excitement for the confirmation of water ice (in abundance) on the Martian surface. The Phoenix Mars lander has been working on the Red Planet for 57 Sols (a.k.a. Martian days) since it landed on May 25th, the robot has pretty much operated as planned, exceeding all expectations (to be honest, I was relieved it touched down in one piece, anything else was a bonus!). But today, the lander releases a stunning image from its Surface Stereo Imager that really brings the whole mission into perspective: Martian midnight Sun…

I remember looking toward the horizon on a frozen Arctic night, beginning another all-nighter at the world’s most northerly university, UNIS. I was with my friend and colleague Gareth Thomas and we had decided to return to the office to put some extra hours into our project. This was back in 2002 and we were exchange students in the Norwegian town of Longyearbyen, on the archipelago of Svalbard studying the upper polar atmosphere and magnetospheric physics (all great fun, especially when the aurora put on a show). However, that night holds a special memory for me. For the first time, I realised that I was looking at the Sun, hanging above the mountains on the horizon at the dead of night, midnight. It was an eerie experience, but it was an amazing one. As we were located so far north (78° north), the Earth’s tilt suddenly had a practical reality, it gave us 24 hour light during summer and 24 hour darkness in winter.

It probably comes as no shock that Mars also experiences 24-hour night/day during the winter/summer as the Red Planet also has a similar tilt on its axis. The Phoenix mission planners had deliberately picked Martian summer so the polar temperatures would be a little less harsh on the robotic explorer. But Phoenix has spent some time documenting the summer polar phenomenon, midnight Sun, when it hasn’t been carrying out excavation tasks, producing the stunning series of pictures seen above. From Sols 46 to 56, Phoenix has directed its Surface Stereo Imager to the horizon between 10pm and 2am to capture the lazy sunset and sunrise. The Sun never drops below the horizon.

Over the next few days, commands will be sent to the lander to monitor the northwestern horizon for dust devils. Observations of these short-lived, small-scale weather events will help the Phoenix team piece together the climates of the polar and equatorial regions. Similar surveys have been carried out by NASA’s Mars Rover Spirit just south of the equator. Students from Arizona and California will then analyse the images to see if dust devils are present. Interns from all over the US hope to participate in the project throughout the summer.

Source: Phoenix mission site