Mars is a planet that has fascinated people for centuries. It has a rusty red appearance, unusual moons and is one of the most explored bodies in the solar system.
Like Earth, Mars has seasons, polar ice caps, volcanoes and canyons. The planet also has a thin atmosphere made of carbon dioxide, nitrogen and argon.
1. What is Mars?
Mars is the fourth planet from the sun, and it orbits once every 687 Earth days. It is a rocky world with canyons, volcanoes and craters all over it. Red dust covers much of the planet, just like it does on Earth. Sometimes the dust winds up and blows into a big dust storm.
It has a very thin atmosphere, consisting of carbon dioxide, 1.93% argon and 1.89% nitrogen along with traces of oxygen and water. The atmosphere is so thin, in fact, that it can be seen with the naked eye.
Scientists have found that the atmosphere of Mars has changed over time. It used to be much thicker and could have been a good place for life to live.
But that was long ago, 3.5 billion years. There are many features on Mars that show evidence of a watery past, including ancient river valley networks and deltas, lakebeds and even rocks that were formed in liquid water.
A few scientists have even imagined that Mars might be a suitable place for life. For instance, Percival Lowell believed that he had seen a network of long, straight canals on the Red Planet.
This idea has been largely disproved, however. The canals he thought he saw were just geological features, not a sign of life or civilization.
In the early 1960s, robotic spacecraft began observing Mars. The first of these was the Mariner 4 mission, which launched in 1964. It discovered many of the planet’s features, including volcanoes and big canyons. Then, in 1971, the Mariner 9 mission took a closer look at the surface and mapped out 80% of the planet’s surface. It also found that there were two natural satellites on the planet, called Phobos and Deimos.
2. What is Mars’s surface like?
Mars is the brightest planet in the Solar System and is often referred to as the “Red Planet.” Its red color comes from the iron oxide that reflects light back to the surface. Its surface is also dotted with large craters.
The surface of Mars is rocky and largely void of vegetation. There are many channels, plains and canyons on the Martian surface that were probably formed by water erosion (water wearing away the surface).
Although today Mars is a cold, dry and sterile planet with a thin atmosphere, it has been known to have liquid water at some point in its history. Geological evidence suggests that this was the case billions of years ago when Mars had a much denser atmosphere and likely sustained oceans or seas.
However, due to the thin atmosphere and the cold temperatures, it is unlikely that liquid water can exist on Mars’s surface now. Atmospheric pressure is extremely low on the planet, with an average pressure of less than 1% of Earth’s and a maximum pressure of only 30 Pa on Olympus Mons, the largest volcano in our solar system.
Because of the thin atmosphere and cold climate, it is difficult for the heat from the Sun to reach the planet’s surface. The temperature of the surface of Mars varies greatly from place to place. The lowest temperature occurs at the planet’s polar caps in winter, and the highest is found during summer.
The surface of Mars is also covered with a thick layer of oxidized iron dust that is constantly kicked up by giant dust storms that can last for months. These dust storms are the most violent in the Solar System and can cover the entire planet.
3. What is Mars’s atmosphere like?
Despite being the farthest planet from the Sun, Mars has a relatively thin atmosphere. It’s made up of about 99% carbon dioxide, 3% nitrogen, 1.6% argon and small amounts of other gases. It also contains traces of oxygen, carbon monoxide, water, methane and other gases, along with a lot of dust that hangs in the air and colors Martian skies tan.
Although the amount of carbon dioxide in the atmosphere on Mars is very small, it’s a poisonous gas at high concentrations. So it’s best to stay away from it if you can.
In addition to the carbon dioxide, Mars has trace amounts of other gases, such as acetylene, neon, krypton, and methane, among others. These gases are produced by photochemical reactions, but they don’t make up a large portion of the atmosphere.
The amount of trace gases is relatively low because most of them have been stripped out by solar winds, which strip away the atoms in the top of the atmosphere. However, these winds do produce a small amount of ozone in the upper layers of Mars’s atmosphere.
This ozone is a result of water vapor. Water vapor is a very strong greenhouse gas that absorbs heat from the sun. Ozone is a weaker greenhouse gas that reacts with sunlight to form water vapor.
It’s important to remember that the amount of water vapor in Mars’s atmosphere is a tiny fraction of the amount that would be necessary for liquid water to persist on the surface of the planet. This means that if we ever found water on Mars, it would be trapped in the very thin atmosphere of the planet and not be able to escape into space.
4. What is Mars’s interior like?
The interior of a planet is usually invisible from the surface, but thanks to new data from a spacecraft on Mars, scientists can now reveal what it looks like inside the Red Planet. The first direct seismic observations from a lander aboard the planet, presented in three studies published today in Earth Science, help researchers map for the first time what makes up a planet’s internal structure.
A molten core sits beneath the cold surface of the planet, and that’s likely where most of the earthquakes on Mars occur. Seismic waves from those quakes, called marsquakes, vary in speed and shape when traveling through different materials within the interior of the planet.
These variations give seismologists an opportunity to map the internal structure of Mars and learn more about how rocky planets like Mars and Earth formed.
In addition to the molten core, a solid crust and mantle are likely present, with the crust being about half as thick as Earth’s. The mantle is about twice as thick, and it stretches down about 969 miles (1.560 kilometers) below the surface.
The crust and mantle of Mars also have a thin upper layer, which is thought to be made up of peridotite, a form of rock that includes silica. This layer is about 12 miles (19.3 kilometers) deep and may contain sublayers that extend down about 23 miles (37 kilometers).
The mantle is largely made of peridotite, which contains more silica than basalt, but it is also composed of rock that contains varying amounts of magnesium, iron and sulfur. The crust is probably a mix of peridotite and basalt, as well as other types of rock that are common in the crusts of the Earth and moon.
5. What is Mars’s surface like?
Mars is a large, red, rocky planet. It is shaped like a ball and it has a thin atmosphere that protects it from the Sun. It has clouds, winds, a roughly 24-hour day, seasonal weather patterns, and polar ice caps.
Its surface is mainly made of rock and dust. It has a red color, which is caused by sand-blasted gravel on the surface that is rich in Si and Fe oxide.
The surface of Mars is dotted with craters, canyons, and volcanoes. It is covered with a layer of dust, which also gives it its red color.
Many scientists believe that there was water on Mars in the past. They have found geological evidence of streams, lakes, and rivers on the surface, but these are too young to be seen by humans today.
This is because the atmosphere of Mars is too thin for water to persist as a liquid. It also does not have an ozone layer like Earth’s, which prevents harmful ultraviolet radiation from reaching the surface of the planet.
A large portion of the Martian surface is sterile desert. The rest is composed of rocky debris.
Mars’s northern hemisphere is much more plain than its southern hemisphere, which is dominated by ancient cratered highlands. These craters may have been formed by a planetary collision four billion years ago, which was one-tenth to two-thirds larger than the Moon’s impact basin.
The northern plains of Mars are more smooth at kilometer (mile) scales than the south, and they contain large amounts of lava flows. These flows can be traced back to eruptions in the ancient era, which suggests that Mars once had water.