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Mars 2003 Observations
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| South is at the top. The phase of Mars is now clearly visible as it moves away from opposition into the evening sky. The dawn terminator is to the right (east). The colour rendition and contrast have been adjusted to resemble the visual impression of Mars in a small telescope. |
| South is at the top. The dark marking at about 10 o'clock and halfway from centre to edge is Solis Lacus. The dark area at about 2 o'clock is Mare Sirenum. The phase of Mars is beginning to be clearly visible as it moves away from opposition into the evening sky. The dawn terminator is to the right (east). The colour rendition and contrast have been adjusted to resemble the visual impression of Mars in a small telescope. Disk diameter 23.25 arcseconds. |
| The South Polar Cap (top) is shrinking rapidly and is now a small white patch. The prominent, V-shaped feature is Syrtis Major. The rotation of the planet in the 1h39m interval between exposures is obvious (Mars' rotation period is 24h 37m). |
In mid-October, Mars has risen above the south-east horizon after sunset, so one has to wait an hour or so for it to rise high enough in the sky to observe conveniently. On August 28th, Mars reached `opposition', which means that as viewed from the Earth, its orbit brought it exactly opposite the Sun in the sky. In mid-October, Mars appears at its highest in the night sky at around 2200 BST, when it is due south. From London, it reaches just over 20 degrees above the southern horizon at its highest.
Mars can be observed for some weeks near
opposition, although it will fade slowly as the Earth moves ahead
of Mars in its orbit and Mars gets further away. As we move into
October and November, it will rise earlier in the evening sky.
Through a small telescope, Mars appears as a distinct reddish, disc. The
red colour comes from rust - iron oxide - which makes up about 10 percent
of Martian soil.
One should also be able to make out the white, southern polar
caps, composed of solid carbon-dioxide and water ice, and observers
may be able to make out the difference in colour between the southern and
northern hemispheres of Mars: the predominantly
ancient cratered surface appears light red, while the smooth,
low-lying plains appear darker red.
In order to make out more detailed features, one needs to use a larger
telescope or have access to more sophisticated imaging equipment; steady
atmospheric conditions also help a great deal. At
University College London's observatory in Mill Hill, astronomers have
been observing Mars through the Fry 8-inch refracting telescope. Images of
the planet have been recorded using a low-light-level video camera; the
sharpest frames from the video footage are then selected and combined
together to give a higher-quality image which can be digitally
enhanced, enabling more surface
details to be made out. The images shown at the top of the page were obtained
in this way.
Observations made with the Fry 8-inch refractor, and recorded using a hand-held
digital camera, by Dr. Mike Dworetsky and Dr. Francisco Diego.
The view through a telescope
2003 August 7th
Dr. Mike Dworetsky observing Mars with the Fry Telescope at 01:44 UT.
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