Mars weather is proving turbulent and varied over the Perseverance rover’s landing site in Jezero Crater.
NASA agency Rover Perseverance It contains several weather sensors, collectively called the Mars Environmental Dynamics Analyzer (MEDA), that cover the rover’s neck and surface; Some of them are also inside. Scientists have now released a MEDA weather report for the project’s first 250 Martians (Martian days, each about 40 minutes longer than an Earth day), and the results describe a surprisingly dynamic atmosphere near the surface of the Red Planet.
MEDA, built by Spanish scientists led by José Antonio Rodríguez Manfredi of the Center for Astrobiology in Madrid, includes five button-sized sensors that routinely measure Mars air temperature at four different heights to create a vertical temperature profile; Two wind speed sensors. and additional sensors to measure radiation, dust, humidity and air pressure.
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The Red Planet’s northern hemisphere spans spring into early summer, and the results focus on the “atmospheric surface layer (ASL)”—the lowest layer of Earth’s atmosphere. Mars atmosphere that touches the surface of the planet. Heat and mass in the form of dust are exchanged between the surface and the ASL, with each region influencing the other.
Perseverance has measured the average air temperature in Jezero to be minus 67 degrees Fahrenheit (minus 55 degrees Celsius), but this can vary by 90 to 110 degrees Fahrenheit (50 to 60 degrees Celsius), especially between day and night. Air pressure also fluctuated, daily and significantly more on a seasonal basis, as carbon dioxide warmed at the poles in the “heat” of early summer, boosting the thin atmosphere.
“The pressure and temperature of the Martian atmosphere fluctuate with the periods of the Martian solar day… yet the daily cycle of sunlight is greatly affected by the amount of dust and the presence of clouds in the atmosphere,” said report co-author Agustín Sánchez-La Vega, from the Planetary Sciences group. University of the Basque Country in Spain, at statment.
As the sun’s daytime temperature at the surface warms and the atmosphere decreases, pockets of air begin to rise, creating mild turbulence that leads to some noticeable fluctuations in temperature. The disturbance stops in the evening as the sun It sinks toward the horizon and solar heating decreases, allowing the air to settle, at least for a short time.
Then, Perseverance often measures the instability returning to the ASL at the equivalent of around 2 a.m. Martian local time. Similar instability returns have also been witnessed by NASA InSight landerwhich ended its mission in December after four years on the Red Planet. MEDA has now confirmed that this is caused by the warm surface of the local terrain, boosted by winds at gentle speeds of 6.5 to 13 feet (2 to 4 meters) per second driven by differences in surface temperature.
Speaking of winds, MEDA measured the daily wind cycle, with strong southeasterly gusts of 82 feet (25 m) per second around midday, weaker winds of 23 feet (7 m) per second in the afternoon, and a reversal of wind direction at night , and no wind at all between 4 a.m. and 6 a.m. local time.
previous results They showed how perseverance revealed dust devils passing over the rover and an accompanying change in air pressure.
“Dust devils are more abundant in Jezero than anywhere else on Mars, and they can be very large, forming whirlwinds over 100 meters high. [330 feet] in diameter, Ricardo Hueso, of the Planetary Sciences group at the University of the Basque Country, said in the release. [their size and abundance] But also to reveal how these whirlwinds work.”
Understanding the atmosphere of Mars today is important not only because of scientific curiosity. It can also affect the missions that land on the planet. In addition, the 10 sample of cans Left on the ground by Perseverance as it rolls around Jezero Crater, it will be continually exposed to atmospheric conditions for many years; A future mission to retrieve it is currently scheduled to land on the Red Planet in 2031.
The results are published Jan. 9 in the journal Natural Earth Sciences (Opens in a new tab).
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