Perseverance rover releases first detailed weather report

Martian weather turns turbulent and varied over the landing site of the Perseverance rover in Jezero Crater.

NASA’s Perseverance rover is littered with various weather sensors, collectively called the Mars Environmental Dynamics Analyzer (MEDA), that cover the rover’s neck and deck; some are also housed in its interior. Scientists have published a MEDA weather report for the project’s first 250 sols (Martian days, each about 40 minutes longer than Earth’s), and the results describe a surprisingly dynamic atmosphere near the surface of the Red Planet.

Created by Spanish scientists led by José Antonio Rodriguez-Manfredi of the Center for Astrobiology in Madrid, MEDA includes five button-sized sensors that routinely measure the temperature of Martian air at four different altitudes to create a vertical temperature profile; two wind speed sensors; and additional sensors to measure radiation, dust, humidity and atmospheric pressure.

Related: Perseverance rover spots Ingenuity helicopter resting on sand dune (pictured)

Spanning the Red Planet’s northern hemisphere from spring to early summer, the results focus on the “surface atmospheric layer (ASL)” — the lowest layer of Mars’ atmosphere that comes into contact with the planet’s surface. There is an exchange of heat and mass in the form of dust between the surface and the ASL, with each area affecting the other.

Perseverance has measured that the average air temperature in Jezero is minus 67 degrees Fahrenheit (minus 55 degrees Celsius), but it can vary from 90 to 110 degrees Fahrenheit (50 to 60 degrees Celsius), especially day and night . Atmospheric pressure also fluctuated, both daily and, more markedly, seasonally as the carbon dioxide frost at the poles sublimated at the onset of the summer “heat,” reinforcing the thin atmosphere.

“The pressure and temperature of the Martian atmosphere fluctuate depending on the periods of the Martian solar day … after the daytime cycle of sunshine, the amount of dust and the presence of clouds in the atmosphere have a big influence,” Agustin, co-author of the report. Sanchez-Lavega of the Planetary Sciences Group at the University of the Basque Country in Spain, the statement said.

As the daytime sun warms the surface and lower atmosphere, the air pockets begin to rise, creating mild turbulence that results in some of the observed temperature fluctuations. The turbulence stops in the evening as the sun dips towards the horizon and solar heating drops, allowing the air to settle, at least for a short time.

Perseverance then frequently measured the instability returning to ASL at around 2am local time on Mars. A similar returning instability was also witnessed by NASA’s InSight lander, which ended its mission in December after four years on the Red Planet. MEDA has now confirmed that this is the result of the terrain’s warm surface, amplified by winds of 6.5 to 13 feet (2 to 4 meters) per second due to differences in surface temperatures.

Speaking of wind, MEDA measured the daily wind cycle: a strong southeasterly wind of 82 feet (25 m) per second around noon, a weaker wind of 23 feet (7 m) per second in the afternoon, a change in wind direction. at night, and from 4 to 6 am local time there is no wind at all.

Previous results showed how Perseverance detected dust swirls passing over the rover and the change in barometric pressure that accompanied them.

“Dust plumes are more numerous at Jezero than anywhere else on Mars and can be very large, forming swirls over 100 meters high. [330 feet] in diameter,” Ricardo Hueso, also of the Planetary Sciences Group at the University of the Basque Country, said in a statement. “With the help of MEDA, we were able to characterize not only their general aspects. [their size and abundance] but also to understand how these vortices operate.

Understanding the modern atmosphere of Mars is important not only because of scientific curiosity. This can also affect missions landing on the planet. In addition, the 10 sample canisters left on the ground by Perseverance as it rolls around Jezero Crater will be exposed to the weather continuously for years; a future mission designed to retrieve them is currently due to land on the Red Planet in 2031.

The findings were published on 1 January. 9 in Nature Geoscience (will open in a new tab).

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