Mars may appear to have seasons, but they’re much more complex than you might realize. Due to its thin atmosphere and lack of oceans, its climate changes rapidly between seasons.
Mars weather can vary daily and even over short distances. Cloud cover, precipitation and wind speed all play an integral part of its climate system.
Temperature
Mars’ climate can be extremely harsh, particularly at its polar regions. At the north pole temperatures can plummet as low as -125degC (-200 kelvins), leading carbon monoxide in the atmosphere to condense onto surfaces as dry ice that expands during wintertime only to shrink back during summer.
Mars lies further from the sun than Earth and receives less radiant heat; therefore its temperatures fluctuate more wildly.
Water can find it difficult to circulate in Mars’ atmosphere. Scientists suggest it could exist on Mars; however, keeping its contents liquid may prove challenging in such hostile conditions.
Scientists do not see it as beneficial to place liquid water on Mars for extended periods, according to studies.
NASA launched several rovers to better understand the weather on Mars. One, Perseverance, contains a meteorological instrument known as MEDA that will aid them.
This instrument can measure various atmospheric conditions, from temperature and wind speed to cloud cover and precipitation levels. It also records data related to these factors.
These rovers also measure dust levels, which is an indicator of air pollution, while taking pictures of landscape features like rocks and plants.
Mars weather can be extremely variable and fluctuate dramatically from day to day, and MEDA instrument onboard the rover is capable of measuring an array of conditions such as temperature and wind speed. Furthermore, it records information such as cloud cover, rainfall and snowfall for further study.
Humidity
Mars may appear dry and barren, but its atmosphere could actually contain humidity. Some scientists argue that if any atmospheric water condenses into puddles on Mars’ surface it could support life.
Liquid water is essential to life; however, some organisms – like lichens – can thrive even in extremely dry climates without needing liquid water for survival.
Scientists are conducting extensive studies of how various kinds of lichens adapt to life on Mars. Their goal is to ascertain if any variety can thrive there using only humidity as its sole resource.
Rummel claims that Mars can experience surprising moisture at night, sometimes reaching humidity levels between 80-100% or even higher.
Mars experiences higher temperatures during the day than Earth and this makes its air far drier.
Summer air around the equator tends to be dry while humidity levels during winter can drop as low as 70 percent.
Water vapor cannot remain in the air without an ideal temperature environment for its retention.
As these variations can make the weather on Mars much more unpredictable than on Earth, it is vital that scientists have access to an authoritative weather data source which allows them to make reliable forecasts about what the future of Mars weather might hold.
Researchers are in search of an accurate relative humidity sensor capable of collecting readings on Mars’ surface. One promising device designed by FMI that may do this is MEDA HS, installed aboard Perseverance when she arrived at Jezero Crater in February 2021.
Clouds
Clouds provide researchers with insights into planet’s weather conditions and climate shifts, and a recent data visualization by NASA illustrates their effects. A visual display shows how clouds change on Mars.
As is true for Earth, Mars features an atmosphere made up of various gases like oxygen, carbon monoxide, nitrogen and argon; however, due to the thin atmosphere on Mars it’s difficult for clouds to form on this world.
Accordingly, both NASA’s Perseverance mission and Curiosity rover scientists are conducting studies of Martian cloud formation. Their aim is to understand how clouds form under such harsh environmental conditions on Mars.
One thing the team of the rover has found interesting is the way clouds appear to form higher up than usual in the sky, producing so-called iridescent clouds which shine like stars when lit by sunlight. They resemble our familiar night-shining or noctilucent clouds here on Earth but with subtler hues.
Clouds seem to rise from behind the atmosphere to high altitude, then dip back down with an arch-shaped formation at their bases – this discovery should help us identify what types of clouds form on Mars’ skies.
We will search the MCS images sent back to Earth for these iridescent clouds and add them to our database of high-altitude Martian clouds, in order to gain more knowledge about the various kinds of clouds on Mars, what materials they’re composed of and their influence on climate conditions on the planet.
Rain
Rain is something we often associate with Earth, but it also falls on other Solar System planets. Carbon dioxide snows on Mars; liquid methane rains on Titan; diamond rain could even form on Neptune if there’s enough sulfuric acid present in its atmosphere!
Mars initially formed some 4.5 billion years ago with an atmosphere four times thicker than modern Earth, meaning water droplets would have been larger, heavier, and more intense than they are on our home planet today.
Two geologists conducted detailed modeling on how early Martian rain may have appeared, taking into account atmospheric pressures and gravity differences on each planet. They used similar models used here on Earth but adapted them to account for differences on Mars as well.
Scientists found that in certain conditions, ancient Martian rain may have lasted as long as a thunderstorm on Earth and transformed Mars more significantly than fog-like droplets. Furthermore, they calculated maximum size, terminal velocity, and intensity of each raindrop that fell on Mars.
Their findings indicate that Martian valley networks were likely sustained by large rainstorms at least 3.5 billion years ago; then around 3.8 billion years ago, rain became less regular and valleys dried out.
However, valleys remain on the planet today; they were likely formed by water once flowing through them and their dust is still rising from below the surface – possibly as a reminder of an earlier watery climate; it will require further investigation before an answer can be provided.
Snow
Mars is an inhospitable planet with no magnetic field and an uneven tilted axis of rotation that means its liquid water cycle differs significantly from that of Earth, meaning rain does not fall as often but instead comes in the form of snowfall.
Mars’ carbon dioxide-based ice formations, commonly referred to as dry ice, may cover several feet in winter on its surface. Instead of melting away into a liquid state like water would, sublimation occurs and converts directly from solid state into gaseous state; similar to how water freezes into snowflakes.
Scientists have not been able to capture images of falling snowfall on Mars due to orbiters and robotic rovers’ inability to peer through thick clouds, until NASA’s Mars Phoenix lander noticed first signs of snowfall from above – though it did not reach ground level.
New research suggests that small specks of water-ice might make their way down to Mars without getting frozen up by carbon dioxide and would then fall similar to they do here on Earth.
This research, recently published in Nature Geoscience, involves an analysis of planetary waves — or periodic fluctuations in temperature that occur throughout our atmosphere — which are present all over.
Atmospheric waves occur frequently and reach heights of 20 kilometers in all layers of the atmosphere, with each wave exerting an immense influence over cloud formation in Martian polar regions. When temperatures in these layers dip below -128 degrees Celsius, scientists’ calculations have demonstrated, small ice crystals begin forming within clouds.