How’s the Weather in Jezero Crater? According to Perseverance: Cold

On February 18th, 2021, the Perseverance rover landed in the Jezero crater on Mars. Shortly thereafter, it powered up some of the scientific instruments it will use to conduct science operations and search for potential evidence of past life. One such instrument is the Mars Environmental Dynamics Analyzer (MEDA), which turned on for 30 minutes and issued the rover’s first weather report from Mars.

The forecast? Bitter Cold! Basically, the temperature was lower than what you’d expect on a harsh and windy winter’s night here on Earth! According to the data the rover sent back, which was received by mission controllers at 05:25 P.M. EST (08:25 P.M. PST), the local temperature around the Octavia E. Bulter landing in the Jezero crater was -20 °C (- 4 °F) when MEDA started recording, then dropped to -25.6 °C (-14 °F) within 30 minutes.

The MEDA instrument weighs roughly 5.5 kg (12 lbs) and contains a suite of sensors designed to analyze the weather on Mars by recording dust levels and six atmospheric conditions – wind speed and direction, atmospheric pressure, relative humidity, air temperature, ground temperature, and radiation (from both the Sun and space). The system wakes itself up every hour and goes to sleep independently after recording and storing data.

On Feb. 19^th, MEDA powered up for 30 mins and sent the instrument’s first data points back to Earth, which allowed NASA engineers to piece together the first weather report from Mars. Dr. Jose Antonio Rodriguez-Manfredi, an engineer with the Centro de Astrobiología (CAB) at the Instituto Nacional de Tecnica Aeroespacial (INTA) in Madrid, is also the principal investigator of the MEDA instrument. As he related in a recent NASA press release:

“After a nail-biting entry descent and landing phase, our MEDA team anxiously awaited the first data that would confirm our instrument landed safely. Those were moments of great intensity and excitement. Finally, after years of work and planning, we received the first data report from MEDA. Our system was alive and sending its first meteorological data and images from the SkyCam.”

The MEDA instrument is similar to the Rover Environmental Monitoring Station (REMS) aboard the Curiosity rover, which provides similar daily weather and atmospheric data from its position inside the Gale Crater. Developed by the CAB with contributions from the Finnish Meteorological Institute (FMI) and NASA’s Space Technology Mission Directorate (STMD), MEDA builds on the REMS autonomous weather capabilities with some added features and updates.

These provide MEDA will greater overall durability and allow it to obtain additional temperature and radiation readings from the surface and atmospheric readings for elevations up to 30.5 m (100 ft). After comparing radiation and dust readings from MEDA with readings obtained by the REMS, engineers found that atmospheric conditions in the Jezero crater were cleaner than they were in the Gale Crater – located roughly 3,700 km (2,300 mi) away.

A subsequent report, based on data collected on April 3rd and 4th (Sol 43 and 44) showed a temperature high of -22 C (-7.6 F) and a low of -83 C (- 117.4 F) in Jezero Crater. In addition, MEDA’s sensors measured wind gusts at around 10 m/s (22 mph) and air pressure readings of 718 Pascals (7.18 millibar) – less than 1% of Earth’s atmosphere – placing it well within the 705-735 Pascal range predicted Martian climate models.

These readings are part of a larger effort to characterize Mars’ atmosphere and weather patterns, which will shed light on how the planet underwent significant changes in its climate over time. As Manuel de la Torre Juárez, the deputy principal investigator for MEDA at NASA’s Jet Propulsion Laboratory (JPL), declared:

“We’re very excited to see MEDA working well. MEDA’s reports will provide a better picture of the environment near the surface. Data from MEDA and other instrument experiments will reveal more pieces of the puzzles on Mars and help prepare for human exploration. We hope that its data will help make our designs stronger and our missions safer.”

So far, scientists have learned a great deal about Mars’ climate and the magnitude of its annual dust storms thanks to the many landers, rovers, and orbiters that have analyzed it in the past few decades. However, there are still many factors that scientists don’t fully understand that would help them predict future storms (such as dust lifting and transport and how small storms evolve into planet-encompassing ones).

Over the next year, MEDA will provide valuable insight into Martian weather patterns by measuring temperature and dust cycles, how dust particles interact with light, solar radiation, local winds, and cloud formations. Thanks to these weather reports, engineers now have atmospheric data from three locations on the planet – the Jezero Crater, the Gale Crater, and Elysium Planitia (where the InSight lander is stationed).

This trio and the data they are collecting will enable a deeper understanding of Martian weather patterns and atmospheric phenomena. This information could prove to be crucial when it comes time to plan for future missions. For example, they will help the Perseverance team determine when atmospheric conditions are optimal for flights using the Ingenuity Mars Helicopter.

These will also assist in the design of the planned NASA-ESA Mars Sample Return mission, which will retrieve samples collected and cached by the Perseverance rover. Last, but not least, the temperature, radiation, and weather data provided by MEDA will help prepare astronauts for future crewed missions to Mars (currently planned fr the 2030s) and inform the design of habitats for science operations on the surface.

For more information on Perseverance rover’s instruments and their purpose, check out the NASA mission page.

Further Reading: NASA