Mars

Mars profile

In early cultures Mars was considered threatening and aggressive - probably because its reddish color reminded of fire and blood. The Greeks and Romans even named their gods of war after it. Some facts about our neighboring planet Mars.

Is there life on Mars?

The first real knowledge about our neighboring planet came from the Dutchman Christiaan Huygens. He observed the sky with telescopes and drew the first map of Mars in 1659.

Huygens already raised the question of life on the Red Planet. The belief in Martians persisted until the middle of the 20th century. As late as 1920, for example, the serious magazine "Scientific American" described a sophisticated signaling system using searchlights and solar reflectors for contacting Martians.

Scientists did not get more real impressions of the Red Planet until 1965, when the Mariner 4 spacecraft transmitted images to Earth that showed only a barren, desolate planet.

Our neighboring planet

Mars is on average about 70 million kilometers farther away from the sun than the earth. In its orbit, it comes closest to Earth every 16 years - about 56 million kilometers.

In August 2003, Mars and Earth came as close as 55 million kilometers. It will not reach this record proximity again until the year 2208.

It is cold on Mars, with violent dust storms blowing across its surface at wind speeds of up to 400 kilometers per hour. The temperature fluctuations are extreme: between minus 125 and plus 35 degrees Celsius, in places within a single day.

There is no dense atmosphere that could allow for more balanced temperatures similar to those on Earth. The atmosphere consists mainly of carbon dioxide and is extremely thin, since Mars has only about one third of the gravitational pull of Earth.

Mars also has something like seasons, albeit of uneven length. Especially in the northern half of the planet, they temporarily provide somewhat more tolerable climatic conditions - a crucial point for future Mars explorations by humans.

Water occurs in the arctic regions of Mars in the form of ice. Near the pole, these ice deposits lie open on the surface. In the south, the pole is additionally overlain by thick frozen layers of carbon dioxide.

Towards the mid-latitudes, water ice can only persist underground under protective dust layers. Scientists suspect larger deposits of liquid water deep in the Martian interior.

Landscapes billions of years old

Presumably, Mars was formed in a similar way to Earth. For this reason, researchers hope to gain new insights into the history of the Earth's formation by comparing rock samples.

Huge chunks of matter accumulated in the course of billions of years due to gravitational influences. The possibly still today liquid inner planet core could have 1500 to 1800 kilometers of diameter.

Many scientists assume that Mars is still volcanically active today, contrary to earlier assumptions. This volcanism could also have periodically transported water to the surface, and the volcanic heat could allow groundwater deposits at greater depths. Future missions, however, still have to prove these underground water deposits.

Volcanic eruptions, along with meteorite impacts, are likely to have shaped the surface structure. One sensational landmark is Olympus Mons, a huge extinct volcano 500 kilometers across at its base and with a crater diameter of 80 kilometers.

At a height of about 26 kilometers, it is the highest point on Mars and the highest known volcano in the solar system. Mount Everest would fit inside it a good three times.

Another natural wonder on Mars is Valles Marineris - a huge canyon system 7000 meters deep and 4000 kilometers long. In comparison, the Grand Canyon of the Earth seems rather small.

Mars has two moons

The Martian moon Phobos (Greek: fear) orbits Mars at a distance of 9400 kilometers in a time of seven hours and 39 minutes. This makes it faster than the rotation of Mars, which means that it moves from west to east as seen from Mars, unlike any other celestial body.

The second Martian moon, Deimos (Greek: terror), orbits the Red Planet at a distance of 23,500 kilometers in 30 hours and 18 minutes.

Both moons, named after the men of the Greek god of war Mars, were discovered in 1877 by the American astronomer Asaph Hall, or more likely guessed - it was probably not possible to see the faint objects orbiting so closely around Mars really well with the telescopes of the time.

Both moons are rather small, they remind of cosmic chunks. Phobos is 26.6 kilometers across at its widest point. Deimos is only about half that size.

Some Mars data compared to Earth

Mars is much farther away from the Sun than the Earth. While our blue planet has an average distance of 149.6 million kilometers to the sun, Mars has 227.9 million kilometers. Accordingly, the Red Planet needs longer for one orbit around the sun, namely 686.98 days on average, compared to the 365.25 days of the Earth.

Mars also takes a little longer to rotate on its own axis than Earth: about 24 hours and 37 minutes compared to about 23 hours and 56 minutes.

In terms of size, Earth has quite a bit ahead of its neighbor. While the equatorial diameter of our planet is 12,756 kilometers, Mars' is only 6794 kilometers.

There are also big differences in the composition of the atmosphere. Earth's atmosphere consists of 78 percent nitrogen, 21 percent oxygen, 0.93 percent argon and 0.035 percent carbon dioxide.

The Martian atmosphere, on the other hand, consists of only 0.3 percent oxygen, 2 to 3 percent nitrogen, 1 to 2 percent argon and 95 percent carbon dioxide.