The largest canyon in the Solar System cuts a wide swath across the face of Mars. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth’s Grand Canyon in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris remains unknown, although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled. Recently, several geologic processes have been identified in the canyon. The above mosaic was created from over 100 images of Mars taken by Viking Orbiters in the 1970s.
On 27 August at 9.51am GMT the Earth is a mere 56 million kilometres away from Mars, and small telescopes will reveal a red disc with dark markings and white ice caps. For experienced observers, the vital statistics at this time are: magnitude -2.9 and diameter: 25.11 arc seconds. Around this date, Mars rises at about 8.30pm in the constellation of Aquarius, the Water Bearer (see the diagram below). Helpfully, the Moon is new on the 27th, leaving the sky perfectly dark for observing. Opposition (when the Earth is aligned directly between the Sun and Mars) occurs the following day, on 28 August at 5.58pm. http://www.bbc.co.uk/science/space/myspace/nightsky/observingnotes.shtml
It won’t quite be close enough to see the details in the Ulli’s picture though
that image is awesome!.. gonna go dig my telescope out and have a looky at mars i seen it the other day while night fishing, mates reckoned it was a star but i was positive it was mars. i didnt know mars was in full view till the day after when i heard bout it on the radio