Do you still remember the lunar eclipse two years ago? At that time the moon was not the only orange-reddish celestial object. Nearby – next to Jupiter – there was Mars in the sky, too. For many people, this was the first time they saw the two planets knowingly "live" – thanks to the attention that the lunar eclipse generated. Unfortunately, the Moon will not give us such a show again this year, but Mars is coming back. As since the beginning of mankind, it can be seen brightly shining in the sky every two years. That's because two Earth years are almost exactly as long as one Mars year, i.e. the time Mars needs for one orbit around the Sun. Only then will it shine again as a bright "star" in our night sky.
THE WARRIOR IN THE SKY, OUR FUTURE HOME?
What impression did a biennial, particularly bright, orange-reddish celestial body, which returns every two years, make on our ancestors? 5,000 or even 10,000 years ago, when humans did not yet live in light-flooded cities that outshine the starry sky, Mars must have been very striking. Every culture has located its gods in the sky and seen their images in the stars. The Greeks connected the red colour of Mars to the blood that is shed in wars. Such a bright, reddish star, which returned again and again, could only be the god of war.
Since those days, our view of Mars has changed, and the significance of our neighboring planet has changed as well, but it has not diminished. Mars is no longer a divine symbol, yet it holds a promise: The journey of mankind to the stars shall find its first goal there, and mankind itself may even find a second home. Our closest neighbour, the moon, was the first celestial body to receive a human visit almost 50 years ago. However, it orbits the Earth and is almost a part of it (in a cosmic sense) – but Mars is a completely different planet! It is a celestial body that orbits the Sun on its own, completely independent of the Earth-Moon-system. If we set foot on it, we have reached a new level of the adventure of space travel, only then will we really have left the sphere of influence of our home planet. This could allow our species to survive even if our ancestral home is destroyed by a cosmic accident or by ourselves, or if the number of people has become so large that the Earth's resources are not sufficient. All this hope is hidden in the orange-red dot in the sky. It is currently enlivened especially by the company SpaceX. Its founder, Elon Musk, has set himself the goal of developing a spacecraft that could fly people and material to Mars in sufficient quantity and in a reasonable time to allow for colonization.
Before humans can land on our neighbouring planet, every two years robotic missions dominate the headlines of the media. This is because a period of good visibility of Mars also means that it is particularly close to us, which has a positive effect on flight time and fuel consumption. Since the first successful landings of robots with the two Viking probes in the 1970s, Mars has been the target of many space missions. This year, several robotic scouts of mankind will set out to further unlock the secrets of Mars. Here is a brief overview: Mars missions planned for 2020.
For the fourth time, the USA is sending a "rover", a travelling science laboratory, which will be accompanied by a mini helicopter for the first time. This small drone will explore the path for the rover. In addition, the carbon dioxide in the Martian atmosphere will be used for the first time to produce oxygen, an important experiment before astronauts can visit the planet. China and the United Arab Emirates are each sending an "orbiter"; i.e. a satellite that orbits Mars, takes photos and acquires measurement data. Although the Chinese orbiter also includes a lander and a rover, they are mainly used to test technologies and promise few scientific results. The European-Russian contribution, a rover called Exo-Mars, unfortunately had to be postponed to the next launch date in two years due to technical difficulties. It was to search for traces of earlier life - just like the US rover "Perseverance" which is now starting.
MARS IN THE TELESCOPE
Mars is a worthwhile destination not only for space probes, but also for eartbound observation and photography. For centuries, the eye was the sharpest detector of (amateur) astronomers. Drawings of the planet were made, internationally compared and evaluated. When there was no Hubble telescope and no satellites constantly orbiting Mars, this work had scientific value.
Even today it is still a very special personal experience to see the solid surface and the weather on the probably most Earth-like planet in the solar system with your own eyes. Orange-coloured to dark-black desert areas, white ice pole caps, clouds and yellowish dust storms can be discovered on our neighbouring planet. Already with small telescopes from about 100mm aperture and about 200x magnification this can be achieved. But since a few years much more detail can be gained with new photographic detectors, CCD and CMOS cameras, and the so-called "Lucky Imaging", which almost eliminates the disturbing effects of the earth's atmosphere.
THE TELESCOPE EQUIPMENT FOR THE OBSERVATION OF MARS
In general a telescope should have at least 100mm aperture – more is better, because the planets are small and the highest useful magnification depends on the diameter of the telescope. As a guideline, the highest useful magnification is twice the aperture in millimetres.
Magnifications of 200x to 300x are worthwhile when observing Mars.
If our own Earth's atmosphere allows it, it is also possible to increase the magnification even further. The larger the aperture of a telescope is, the more details can be resolved. No wonder then that Schmidt-Cassegrains are so popular with planetary photographers: They combine a large aperture and focal length with a compact design, so that no extremely heavy and expensive mount is necessary to carry the telescope stably.
Azimuthal mount or equatorial mount
Whether you use an azimuthal mount, which can be set up in no time, or an equatorial mount, which is optimal for photography, remains a matter of taste on Mars – for planetary photography you can even use an azimuthal mount. The only important thing is that it has a tracking system: Then the planet remains in the field of view even at the highest magnification, and you can observe with complete relaxation.
High magnifications can be achieved with short focal length eyepieces
Orthoscopic eyepieces ("Orthos") are still the first choice for planetary observers because they need just a few lenses to show a bright, high-contrast image; modern wide-angle eyepieces such as the Morpheus eyepieces are not inferior to them and at the same time offer a more comfortable view with a larger field of view – but they also cost much more. With a good Barlow lens, the magnification can be further increased or brought to a value that matches the pixel size of a video module for planetary photography. For highest demands and magnifications you should use the Fluorite Flatfield Converter (FFC) / 3x-8x (#2458200 , € 730) .
Colour filters help to better highlight delicate details
For surface details on Mars, red and orange filters have proven their worth. A green filter helps in the hunt for fog fields and CO2 rime, while a blue filter shows surface details and the violet clearing. Changing the filter is particularly convenient with a filter slider or wheel.
Relaxed observation with binoculars
Relaxed observation is possible with a binoviewer (for example with our Baader MaxBright® II binoviewer). We use two eyes during the day, why should we do without them in the night sky?
Remember the Star Diagonal
Often a bad image is not due to the telescope, but to the simple star diagonal that is included. We offer a range of mirror and prism diagonals. There is also an especially interesting option if you are doing both photography and visual observations: With the Baader FlipMirror II Star Diagonal (#2458055 , € 228) you can switch from eyepiece to camera in seconds, and of course it can be combined with filter sliders / wheels.
About the author: Michael Risch
Michael has been interested in astronomy and spaceflight, since he saw the last moon landing as a child. In 1981, he became a member of the Association of Amateur Astronomers in the Saarland and, as a member of the board, accompanied the establishment of the Peterberg Observatory. As co-founder and first webmaster of www.astronomie.de, he contributed numerous ideas and reports on astronomical and spaceflight topics to the first German astronomy portal. He has been practicing planetary, comets, solar, deep sky as well as TWAN style photography, and has been on many long distance trips, among others to 7 total solar eclipses. As a long-time science editor, he has led "Northern lights and stars" trips to the Arctic Circle. Michael has published many of his own photos and articles in professional journals and has written chapters for the books chapters for the books Fotoschule (Photo School) and Extremfotografie (Extreme Photography) with his colleague Martin Rietze for "Color Foto".
At Baader-Planetarium he is part of the observatory project team and is booked for lectures in Germany and abroad. Furthermore, he is an expert consultant for observatories, domes, high end mounts, telescopes and much more.