Mars is one of the most popular planets in science fiction and has inspired generations of writers. It is also the only planet on which scientists have ground-based rovers and landers that transmit data.
Despite its thin atmosphere, which is less than 1% that of Earth, liquid water appears to have existed on the surface in the past, based on features like canyons and dry lakebeds.
It is a red planet
Mars is a planet in our solar system that is half the size of Earth. It is a rocky, terrestrial planet that is famous for its red color. This color comes from rusty iron that has oxidized on the surface of the rocks and dust.
Another reason why Mars is red is because of its thin atmosphere, which allows sunlight to reflect off the planet. This happens because of a phenomenon called Rayleigh scattering, which causes light that hits particles smaller than the wavelength of that light to appear red.
In addition, Mars experiences huge dust storms. These storms happen every year, and they can cover large areas of the planet and last for weeks at a time.
Because of the shape of Mars’ orbit around the sun, these dust storms tend to be oval shaped. This makes them bigger and more intense than the storms on many other planets.
The dust in these storms is a combination of iron oxide and oxygen. When it combines with oxygen, it produces a red color that’s what gives the planet its nickname “red”!
When viewed from space, the planet appears to be a brighter red than it is when seen from Earth. This is because Mars has more light coming from its two brightest stars, Aldebaran and Betelgeuse.
NASA has a fleet of orbiters and rovers exploring Mars from space. These include the 2001 Mars Odyssey, Mars Reconnaissance Orbiter and MAVEN. These robotic explorers have found a lot of evidence that Mars was a wetter, warmer, thicker and more dense world billions of years ago.
It has a thin atmosphere
Mars has a thin atmosphere, less than 1% of Earth’s pressure. This makes it more difficult to live on the planet.
The atmosphere of Mars is mainly carbon dioxide, with small amounts of nitrogen, argon, oxygen and other gases. It also contains trace amounts of methane and ozone.
This thin atmosphere prevents water from evaporating into space. It also makes the planet’s surface hotter than it would be otherwise, so it can be hard to grow food even in a greenhouse on Mars.
It’s likely that there was liquid water on the Martian surface at some point, but for reasons that are still unclear the atmosphere has thinned to a point where it is now unable to support life. This is a problem that can have serious consequences for future human exploration of the planet.
One of the most obvious effects of a thin atmosphere is that sound travels slower than it does on Earth. Researchers have recently found that low-pitched sounds on Mars travel at 240 metres per second, while higher-pitched sounds hardly move at all.
Another way that a thin atmosphere affects sound is that it causes it to spread over a shorter distance. This means that it’s easier for a person on Mars to hear other people.
The Martian atmosphere also has a tendency to lose gas, which is causing the planet’s climate to change. This process has been observed by a NASA spacecraft called MAVEN, which is tracking the planet’s loss of gases. The MAVEN team tracked the rate at which argon, which is a noble gas that can’t be sequestered in rocks, was lost to space. This was due to a physical process that removes the gas from Mars by interacting with the solar wind.
It has polar ice caps
Mars has polar ice caps that are made up of frozen water and carbon dioxide gas. The ice caps change with the seasons on mars, becoming much larger in the winter and shrinking during the summer.
The north polar cap is composed of ordinary water ice and the south polar cap is composed of dry ice (carbon dioxide). It’s not very thick, but it covers a huge area.
During the winter, the temperature on mars is so cold that carbon dioxide freezes and forms dry ice. This ice is only a few meters deep in the north and eight meters deep in the south, but it covers a massive area.
In the summer, when the temperatures are warmer, the dry ice melts and disappears into the atmosphere. This leaves channels of ghostly spiders carved in the surface.
A new study suggests that liquid water may have been present beneath the Martian south polar cap for hundreds of thousands of years, but scientists haven’t known where this water was. Now, a team of scientists has used spacecraft laser altimeter data to identify subtle patterns in the upper surface of the polar cap and show that these patterns match predictions about how a body of liquid water would change its shape.
The researchers also showed that the dry ice on the south polar cap is about three times as enriched in deuterium, an isotope of hydrogen, as is water on Earth. This is the first independent evidence for liquid water beneath Mars’s south polar cap.
It has dunes
In a story straight out of science fiction, a plucky rover on a mission roves through a desert sea of wind-whipped dunes. The dune field may look like a bleak landscape, but it’s not the only feature on Mars that’s changing.
Scientists have found an ancient dune field on Mars that has lasted for billions of years. The dune field is tucked away in a canyon on the planet, and the scientists say it’s unlike anything else on Earth.
The dune field consists of large, ancient sand dunes that were preserved in Gale Crater and are thought to date back about 1 billion years. It’s a unique find that allows us to learn about how Mars has evolved over time and how it was affected by the weather.
Astronomers have also found evidence that the planet’s climate and atmosphere has remained consistent over time. This is because palaeo-dunes in the widest part of Valles Marineris, known as Melas Chasma, are similar in size and shape to sand dunes formed today on the planet.
This could indicate that the Martian climate has changed little over time, and that the major wind directions that drive sand dunes on the planet have not changed much either.
Researchers have also discovered that some dunes on Mars are shaped like barchans, which are crescent-shaped dune fields. These barchans can be formed in any size from finger-length dunes on the ocean floor to stadium-sized dunes in the deserts of the Earth.
The new findings are significant because they reveal how air flow affects ripples and dunes on Mars, which doesn’t have the same density of air as Earth. This means that a shift in the flow of air can control the size of dunes and ripples at all but the smallest scales.
It has dust devils
Mars has dust devils – tornado-like whirlwinds that form in a thin atmosphere on warm summer afternoons. Scientists have captured pictures, collected weather data and even recorded seismic and magnetic signals emitted by these winds.
These swirling dust vortices whirl over the surface of mars – and now, for the first time, scientists have captured their sounds using microphones on a martian rover. By chance, the Perseverance rover in Jezero crater stumbled across one last September – and it was full of sound.
While these storms aren’t as strong as tornadoes, they’re still powerful enough to push debris up into the air – and this could potentially be dangerous for any terrestrial technology that is sent to mars.
They are formed by air being drawn into a narrow column of air rising through surrounding cooler air. That allows the air to rotate more quickly than it would without the narrowing column.
On Mars, this air is much more stable than on Earth because the planet’s lower atmospheric pressure causes it to be pushed with only about 1% of its normal force. This air then lifts up grit particles into the air, making them appear like a dust devil.
It also leaves dark marks on the Martian surface because it scourps the light-toned dust that covers most of Mars, exposing the underlying darker material beneath. On a geological scale, these tracks tend to disappear within days or weeks of their formation.
By combining the sounds, images and other data from the rover’s SuperCam camera and sensors, scientists were able to determine that the towering whirlwind was at least 118 meters high and 25 metres wide. It swept directly over the rover at about five metres per second and was moving at about 12 mph (19 kph).