Artist impression of what a dustdevil would look like for humans standing on Mars, by Ron Miller
The principal investigator is Javier Gómez- Elvira, Center for Astrobiology (Centro de Astrobiología), Madrid, Spain.
The Rover Environmental Monitoring Station, or REMS, will record information about daily and seasonal changes in Martian weather. It will measure wind speed, wind direction, air pressure, relative humidity, air temperature, ground temperature, and ultraviolet radiation. The REMS instrument is designated to work for 5 minutes of each hour during Curiosity’s 98 week (nominal) mission.
Information about wind, temperatures and humidity comes from electronic sensors on two finger-like booms extending horizontally from partway up the main vertical mast holding the ChemCam laser and the Mastcam.
Each of the booms holds a sensor for recording air temperature and three sensors for detecting air movement in three dimensions. Placement of the booms at an angle of 120 degrees from each other enables calculating the velocity even when the main mast is blocking the wind from one direction.
The boom pointing toward the front of the rover, Boom 2, also holds the humidity sensor inside a downward-tilted protective cylinder. Boom 1, pointing to the side and slightly toward the rear, holds an infrared sensor for measuring ground temperature.
The pressure sensor sits inside the rover body, connected to the external atmosphere by a tube to a small, dust-shielded opening on the deck. Electronics controlling REMS are also inside the rover body.
The ultraviolet sensor is mounted on the rover deck. It measures six different wavelength bands in the ultraviolet portion of the electromagnetic spectrum, including wavelengths also monitored from above by NASA’s Mars Reconnaissance Orbiter. No previous mission to the surface of Mars has measured the full ultraviolet spectrum of radiation.
The REMS investigation will strengthen understanding about the global atmosphere of Mars and contribute to the mission’s evaluation of habitability. The data will provide a way to verify and improve atmosphere modelling based mainly on observations from Mars satellites.
On Mars significant fractions of the Martian atmosphere freeze onto the ground as a south polar carbon-dioxide ice cap during southern winter and as a north polar carbon-dioxide ice cap during northern winter, returning to the atmosphere in each hemisphere’s spring. At Curiosity’s landing site, far from either pole, REMS will check whether seasonal patterns of changing air pressure fit the existing models for effects of the coming and going of polar carbon-dioxide ice.
Monitoring ground temperature with the other weather data could aid in assessment of whether conditions have been favorable for microbial life. Even in the extremely low-humidity conditions anticipated in the landing area, the combination of ground temperature and humidity information could provide insight about the interaction of water vapor between the soil and the atmosphere. If the environment supports, or ever supported, any underground microbes, that interaction could be crucial.
Ultraviolet radiation can also affect habitability. The ultraviolet measurements by REMS will allow scientists to better predict the amount of ultraviolet light that reaches Mars’ surface globally in the present and past. Ultraviolet light is destructive to organic material and the reason that sunscreen is worn on Earth.
REMS was build in Spain and will be monitored from the Centro de Astrobiología (Center for Astrobiology) in Madrid, with Javier Gómez- Elvira, an aeronautical engineer, as the leading investigator. The whole Spanish team is about 40 researchers — engineers and scientists together.
The team plans to post daily weather reports from Curiosity.
Air temperature around the rover mast will likely drop to about minus about minus 90 degrees Celsius (130 degrees Fahrenheit) on some winter nights and climb to about minus 30 Celsius (about minus 22 Fahrenheit) during winter days. In warmer seasons, afternoon air temperature could reach a balmy 0 degrees Celsius (32 Fahrenheit ).
The Centro de Astrobiología is affiliated with the Spanish National Research Council (Consejo Superior de Investigaciones Científicas) and the National Institute for Aerospace Technology (Instituto Nacional de Técnica Aerospacial).
Spain’s Ministry of Science and Innovation (Ministerio de Ciencia e Innovación) and Spain’s Center for Industrial Technology Development (Centro para el Desarrollo Tecnológico Industrial) supplied REMS. The Finnish Meterological Insitute developed the pressure sensor.