Could the earth really be Mars?

Mars fact sheet

Is there life on Mars?

The first real insights into our neighboring planet come 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 into the middle of the 20th century. In 1920, for example, the reputable Scientific American magazine described a sophisticated signaling system with headlights and sun reflectors for contacting Martians.

The scientists only got more real impressions of the Red Planet in 1965. When the space probe Mariner 4 radioed images to Earth, they only showed a barren, desolate and desolate planet.

Our neighboring planet

Mars is on average about 70 million kilometers further from the sun than the earth. On its orbit, it comes closest to the earth every 16 years - around 56 million kilometers.

In August 2003 Mars and Earth approached within 55 million kilometers. It will not reach this record level again until 2208.

It's cold on Mars, and huge dust storms move 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, sometimes within a day.

There is no such thing as a dense atmosphere that could allow more balanced temperatures, as on Earth. The atmosphere is made up mostly of carbon dioxide and is extremely thin, as Mars has only about a third of the gravitational pull of the Earth.

There are also seasons on Mars, albeit of unequal length. Especially in the northern half of the planet, they temporarily ensure somewhat more bearable climatic conditions - a crucial point for future human explorations of Mars.

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

Towards the middle latitudes, water ice can only hold itself under protective layers of dust in the subsurface. Scientists suspect larger deposits of liquid water deep inside Mars.

Landscapes that are billions of years old

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

Huge chunks of matter clumped together over billions of years due to gravitational influences. The inner planetary core, which may still be liquid today, could have a diameter of 1500 to 1800 kilometers.

Many scientists suspect that, contrary to earlier assumptions, Mars is still volcanically active today. This volcanism could periodically have brought water to the surface again and again and the volcanic heat could enable groundwater to be found at greater depths. Future missions still have to prove these underground water resources.

In addition to meteorite impacts, volcanic eruptions may also have shaped the surface structure. A sensational landmark is Olympus Mons, a huge extinct volcano 500 kilometers in diameter at its base and a crater 80 kilometers in diameter.

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

Another natural wonder on Mars is the Valles Marineris - a huge canyon system 7,000 meters deep and 4,000 kilometers long. In comparison, the Grand Canyon looks rather small on earth.

Mars has two moons

The Martian moon Phobos (Greek: fear) orbits Mars 9400 kilometers away in a time of seven hours and 39 minutes. This makes it faster than the Martian rotation, which means that when viewed from Mars, it moves differently from all other stars from west to east.

The second Martian moon, Deimos (Greek: horror), orbits the red planet 23,500 kilometers away in 30 hours and 18 minutes.

Both moons, named after the men of the Greek god of war Mars, were discovered or guessed at by the American astronomer Asaph Hall in 1877 - one could probably not really see the faint objects circling so close to Mars with the telescopes of the time.

Both moons are rather small, they are reminiscent of cosmic chunks. The diameter of Phobos is 26.6 kilometers at its widest point. Deimos is only about half the size.

Some Mars data compared to Earth

Mars is much further away from the sun than the earth. While our blue planet has an average distance of 149.6 million kilometers from the sun, Mars is 227.9 million kilometers. The red planet needs correspondingly longer to orbit the sun, on average 686.98 days, compared to the 365.25 days of the earth.

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

In terms of size, the earth has a lot ahead of its neighbors. 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. The 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.