mars... the facts
1. In the western world, the planets and moons that make up our solar system are named after the ancient gods of Greece and Rome. Mars – also known as The Red Planet – gets its name from its colour, visible to the naked eye in the night sky. This red hue reminded the Romans of Mars, their bloodstained war god.
2. The two small moons of Mars have Greek names – Phobos (Fear) and Deimos (Panic) - after the two mythological characters who accompanied the Greek war god Mars. Phobos turns out to be rather well-named, since it is slowly closing in on Mars and will probably crash into it in about 50 million years.
3. Mars itself might be more accurately called The Rust Planet, since its red colour is thought to derive from the oxidization (rusting) of iron-rich rocks and dust, abundant on the surface. Millennia of such rusting have produced the ‘red desert’ landscape familiar to us from the Martian lander photos.
4. The month of March is named after Mars.
5. In comparison with Earth, Mars is about half as big, one and a half times further out from the Sun, and takes twice as long to complete its orbit.
6. Mars is in fact the third smallest planet, after Pluto and Mercury. It has a radius of 3396 kilometres, compared to Earth’s 6378. Mars is the fourth planet from the Sun, the next one outwards after Earth, at about 230 million kilometres’ distance, compared to Earth’s 150 million. The Martian ‘year’ – the time it takes the planet to orbit the Sun once – is 687 days, or about 23 of our Earth months.
7. While it takes about 3 days for a spacecraft to fly from Earth to our moon, it takes about 6 months to fly from the Earth to Mars.
8. Though its reddish colour might make it look warm, Mars is in fact much colder than Earth. Temperatures vary from a chilling –6 degrees Celsius during the Martian ‘summer’ (the period in its orbit when it is closest to the sun) to a mind-boggling -129 degrees Celsius in the winter.
9. This cold is partly due to the very thin atmosphere on Mars, which holds in little of the heat it receives from the Sun. This atmosphere is mainly composed of carbon dioxide, and the average pressure is low - about 7 millibars – or 1% of what we experience on Earth. Even this slight pressure, though, is enough to sustain the extremely strong winds and huge dust storms which can cover the entire planet for months.
10. Because Mars is much less heavy than the Earth, it has a much lower gravity. Human beings standing on Mars would weigh only about two-fifths of what they weigh on Earth, so that they could perform big ‘space jumps’ like the lunar astronauts.
11. Though relatively small, Mars boasts some of the most spectacular geographical features in the solar system. The Valles Marineris – the so-called ‘Grand Canyon of Mars’ – is actually a vast system of canyons, located just south of the Martian equator. The Valles Marineris is about 4000 km long, and up to 600km wide and 10 km deep – 50 times longer, 20 times wider, and 6 times deeper than its earthly counterpart. In fact, the Valles Marineris is as long as the United States itself, spanning about a fifth of the entire distance around Mars.
12. Though relatively small, Mars boasts some of the most spectacular geographical features in the solar system. Just west of the Valles Marineris is a region of Mars called the Tharsis Uplift. This is a bulge on the surface of the planet, about 10 kilometres tall at its highest point and about 4000 km across, covering almost 25% of the surface area of Mars. This region is home to much of Mars’ violent volcanic activity, and is crowned by Mons Olympus (‘Mount Olympus’ – mythic home of the ancient Greek gods), the single largest mountain ever discovered in the Solar System. At its highest point Olympus Mons is 24 km high, about three times higher than Mount Everest. Olympus Mons is a ‘shield’ volcano, formed, like the Hawaiian Islands on Earth, by lava forcing its way up through weak points in the planet’s crust.
13. Most Earthly biologists think that life could evolve elsewhere in the universe only in the presence of liquid water. Mars is now a dry and dusty planet, with its water locked up as ice, mixed with frozen carbon dioxide (‘dry ice’), at the north and south poles. But images of certain surface features – such as eroded channels and layered terrain – have convinced many scientists that billions of years ago Mars had liquid water, including floods and river systems, and perhaps even large lakes and oceans. Such findings increase the possibility that living organisms evolved on Mars. Evidence of these creatures might survive as fossils below the Martian surface.
14. The Mars Meteorite was originally thought to contain such fossil evidence – traces left by ancient microscopic Martian bacteria. Although there is still much disagreement about the meteorite, most scientists now think that it does not, in fact, contain fossils of once-living creatures, or even their ‘footprints’. The meteorite does, however, contain chemical compounds commonly produced by living creatures, which strengthens the possibility that living organisms once existed on Mars.
15. The Mars Meteorite is thought to have come to Earth as the result of a large meteor or comet crashing into Mars millions of years ago. The resulting massive impact would have thrown vast amounts of rock out of Mars’s atmosphere and into space. Floating around the Solar System in the following millennia, pieces of debris would have eventually fallen into the gravitational pull of different planets, including Earth.
16. Since Mariner 4’s first successful fly-by in 1965, Earthly craft have visited Mars over a dozen times, including:
- Mars 2, the first spacecraft to land on Mars in 1971.
- Viking 1 and Viking 2, in August and September of 1976.
- And, after a gap of 20 years, The Mars Pathfinder, which landed successfully in 1997.
17. To date, only American and Russian missions have attempted to reach Mars, but all that is about to change, with the first of a series of European space missions currently heading towards the Red Planet.
18. The European Space Agency, with its multinational management, billion-Euro budgets, and ‘state-of-the-art only’ approach to space technology, is currently gearing up to challenge NASA as the world’s leading space explorer.
19. The Mars Express is ESA’s first interplanetary mission. Launched on 2 June 2003 from Kazakhstan, the Mars Express is an orbiter-and-lander package designed to reach Mars on Christmas Eve 2003. Once there, the orbiter craft will begin high-resolution remote imaging of the planet’s surface, mapping everything from the composition of rocks to weather patterns.
20. Beagle 2 is the name of the Mars Express lander. In keeping with ESA’s ‘only-cutting-edge-technologies-need-apply’ attitude to their missions, this British-built vehicle has the highest instrument-to-mass ratio of any space vehicle yet built. While Beagle 2 will contribute to the orbiter’s task of mapping geographical and atmospheric conditions, it will also have the specific task of attempting to find traces of ancient Martian life.
21. Beagle 2 will land in a region called Isidis Planitia, a large, flat basin where scientists hope that traces of life may be preserved. Its delicate instruments will search both for indirect evidence of life, such as the presence of below-surface water; and more direct evidence, such as the existence of complex, carbon-based residues. It is distinctly possible that the first concrete evidence of life on other planets will be brought back to Earth by a piece of British hardware!
22. NASA have developed Martian Climate Models on computers. One of their goals is to 'grow' human compatible living conditions on Mars one day (imagine that!). There are various theories about what it would take, if it's possible at all. They are adapting the climate models for weather on Earth to test their theories. Some preliminary data is already available. As it's customary to invite climate modellers from around the world to participate in such a process climate modellers are now itching to get their hands on some detailed Martian input data and run their models on Martian conditions. (Source: Atmosphere Modelling Group @ NASA Ames Research Centre.)
23. On August 27th 2003, the orbits of Mars and Earth brought them closer together than they had been for almost 60,000 years. The last ‘people’ to see the Red Planet this close (a mere 56 million kilometres!), and this large in the night sky, would have been cave-dwelling Neanderthals.
24. Although Mars is now gradually moving further away, and so shrinking in our night sky, it is still the brightest object in its part of the heavens, and so easy to spot. Looking to the south-east after nightfall, Mars can be seen as a large, reddish-coloured star sitting in the constellation of Aquarius, low to the horizon.
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