Tonight and every night in the near future, you can see the planet Venus as the VERY BRIGHT star towards the west. If you have a really good telescope you can see that like Earth's moon, the appearance right now is that of a crescent, and not a sphere. So why is it that is so very hard to see the crescent shape with the human eye? It is for three reasons. First, the planet Venus always appears from Earth through a great amount of atmosphere - all of it horizontally with all of the curves that would result from trying to look through eyeglasses at a steep, nearly horizontal angle. Secondly, the light from the object Venus is as great as it is on the Moon - actually greater - but because it is crunched into such a small amount of space as opposed to the width of the Moon as seen from Earth, we see more light than shape. Third it is because of the very light of the yellowish clouds of Venus that we do not see clear shapes as we see in the basalt salts of Earth's moon but rather a fog of clouds. You would not want to live on Mars, because if you think the crushing pressures of living on the bottom of the ocean would be bad, the heat that would strain Shuttle tiles and the even worse crushing pressures on the surface of Venus would be even worse.
Even though I am one of those Republican types, I happen to believe in Global Warming and the idea that we are now reshaping the Earth by deforestation and by anything BUT Fossil Fuels in a way that will change the environment into something that will kill us all. The "proof in the pudding" is in watching temperature changes in and around our cities, where we have erected high rises and urban areas and so on, cutting down every tree in sight in the process, and changing the landscape into asphalt pavement. In cities I have studied, such as Phoenix, Denver, and San Diego - and other cities that have experienced tremendous growth, it is already clear that the pavement and asphalt in the place of what at one time used to be gravel and soil and trees is resulting in TREMENDOUS increases in local and eventually global temperatures. So perhaps the big problem with global warming is not in the smog of carbon-based engines, but rather in the landscape we have "intelligently" built without so much intelligent design.
Next to Mars. It appears in nearly everyone's sky overhead about midnight, and it remains as a very bright object all the way to the blue skies of the predawn minutes. What this means, of course, is that Mars is at "opposition." Two years ago, in the Summer of 2003, we heard all about "the closest approach between Earth and Mars in 60,000 years." Well, that was true. This is because in the August of 2003, Earth was near the outer point of its orbit of the Sun and Mars happened to be at the inner point of its own elliptical orbit of the Sun. Mars is now being "passed up" by Earth again, as it rotates the Sun once every two of our years, so thus, once again it appears out on a limb from us, with the Sun going one direction, and the Mars we are cutting in front of on the inside track as a "full" object on the other side. This happens about once every two years and a few months - the few months difference happens because Earth is moving, too.
Earth and Mars have many similarities, including nearly identical rotation periods approximating 24 hours, but honestly, as good as the fantastic idea of humans living on Mars would be, the truth is you would be much better off on Anartica. When you are right on the surface of Mars, you have some pretty comfortable and warm air at Noon approximating 57 degress, but within only an inch - getting worse with each passing foot because of the thin CO2-based air, the temperature decreases DRAMATICALLY and QUICKLY - so fast that Mars experiences windstorms not unlike Earth's Hurricanes in force, only because of rapid changes in temperature within a short distance. So tonight as you look into the sky, pray for all of the green men from Vulcan who might be staging their arrival from there!
I hate Astrology, and think it is just as nutty as a fruitcake - and as fruity, too. But Astronomy ... God I love it!