In Jezero Crater on Mars, it is one minute before midnight. The two tiny moons of Mars, Phobos and Deimos, as well as the stars’ illumination allow you to faintly discern the outline of the impending delta. Nothing moves because the breeze is too weak tonight to even move a sand grain. Everything is tranquil and serene. Then, out of nowhere, a mechanical whirring sound from another planet appears, and a malformed head emerges from the shadows with five menacingly glinting eyes.
But don’t worry—this is just Perseverance going about its normal business, not a phantom monster or a furious Martian!
The majority of Perseverance’s operations typically take place throughout the day. This is due in part to the rover’s need for illumination when taking pictures or using auto-navigation, as well as the fact that there is more power available. Temperatures drop at night, which means more energy is required to keep things warm, leaving less time for science. You might be shocked by how much Perseverance accomplishes at night, though.
One of the reasons is that the Mars Environmental Dynamics Analyzer (MEDA) keeps collecting meteorological data at night. MEDA monitors turbulence bursts, winds associated with flows down the surrounding crater rim, variations in the quantity of water vapour, and variations in the amount of dust and water ice in the atmosphere at night.
Additionally, the SuperCam microphone routinely captures nocturnal three-minute sound recordings at extremely high frequencies, which provide valuable information regarding small-scale atmospheric turbulence.
The oxygen generating runs for the MOXIE (Mars Oxygen In-Situ Resource Utilization Experiment) are typically scheduled at night as well. This is primarily due to the lower air temperatures at night, which results in the densest air because density is related to pressure divided by temperature. As a result, MOXIE can manufacture more oxygen from Mars’ carbon dioxide atmosphere. The most recent MOXIE nighttime operation, which was planned to coincide with the monthly peak in surface pressure, produced 10.4 grammes of oxygen per hour, which is the greatest rate to date.
Nighttime operations are also possible with the Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) equipment. This is due to the fact that nighttime operation offers the lowest instrument noise and, consequently, the most sensitive detections.
At midnight, what about the five-eyed monster? That is the top of the articulated remote sensing mast positioning itself for Mastcam-Z to take images of Phobos (see image). This offers a measurement of the amount of dust in the overnight atmosphere using visible light, which may be compared to measurements of a similar nature obtained by staring at the sun during the day as well as to MEDA’s infrared observations of dust abundance during the night.
Life is quite busy! However, Perseverance isn’t the only one who works nonstop. Mars 2020 team members residing in Hawaii must report to work at 3am their time because rover operations shifts on Earth can begin as early as 6am Pacific Time. The Mars 2020 crew members in Europe, on the other hand, are unable to go to bed until their morning because rover operations can also begin much later in the day and end in the late evening Pacific Time. Perseverance might thus find solace in the fact that she is not alone in working the terrifying night shift!