Mars returns after extended absence

Published 2:39 pm Monday, November 23, 2009

Once every two years the earth catches up with the red planet, Mars, allowing skywatchers a close-up view of earths third closest celestial neighbor. From now and continuing throughout the winter, Mars will be a conspicuous sight in our night sky being outshone only by the star Sirius, the planets Jupiter and Venus, and the moon.

Of all the planets in our solar system, Mars has aroused the most interest among the general public, mainly because of speculation that life may exist there. This is because Mars is the planet most like earth in terms of its terrain, surface temperature and atmosphere, and the fact that (through telescopes) ice caps are clearly visible at its poles indicating the presence of liquid water.
While no evidence of life has yet been found, Mars is the only planet in our solar system other than earth that could support life. Mercury and Venus (being much closer to the sun than earth) are too hot, while the outer planets, Jupiter, Saturn, Uranus and Neptune, are made up of liquid and metallic hydrogen and have no solid surface.

Mars is also the only terrestrial planet whose surface can be examined with an ordinary telescope (Venus is covered by clouds and Mercury is obscured by the sun). Mars surface features include prominent ice caps at its north and south poles, dry river beds (running water was once present on Mars), a 3,000 mile long canyon (Valles Marineris), and a 15-mile high volcano (Olympus Mons). Olympus Mons is by far the tallest mountain ever discovered being twice the height of Mount Everest.

Dark markings on Mars surface are easily observed under good observing conditions with a moderate sized telescope. Some of these markings are permanent features while others change due to shifting sands and violent dust storms.
Like our own moon, Mars is covered with craters from meteorite impacts, but unlike the moon (which has no weather), many of the smaller ones have been eroded away or covered by sand or molten lava (weather, volcanism and plate tectonics have erased the evidence for 99.99% of earths craters).
Mars has a 24-hour day and a 22-month year. The temperature at the equator may reach a pleasant 50 degrees F. while at night drop to 100 below zero as the thin Martian atmosphere (less than 1% of earths) retains little heat. The gravity on Mars surface is 38% of earths gravity, so if you weigh 200 pounds on the earth, you would weigh 76 pounds on Mars. Going there to lose weight, however, is not an option!
Mars is the only planet upon which it is reasonable to expect that human beings may actually land, and it is possible that both the moon and Mars will be colonized within the next several centuries. However, at its closest point, Mars is 150 times the moons distance, so colonization of Mars by humans will be difficult and dangerous and may never actually happen.
This month, Mars will rise shortly after 10 p.m. in the east/northeast exhibiting an unmistakable reddish color (due to iron oxide dust on its surface). As Mars rises, Jupiter will be setting so between midnight and just before dawn (when Venus rises), Mars will be the brightest object in the sky with the exception of Sirius. Sirius is a dazzling blue-white star located well to the south just below the feet of Orion. Because of the dramatic contrast in color between Mars and Sirius, there is no possibility of confusing one for the other.
The local astronomy club will be on hand at FENCE after sunset tomorrow (Saturday, November 14th) with telescopes set up to show you the many wonders of the night sky including the Andromeda Galaxy, Jupiter with its Gallilean moons, and if you stay late enough the newly arriving and mysterious red planet.
We hope you will join us!