Post by rducasey on Mar 2, 2007 19:13:02 GMT -5
Just noticed while I was walking this huge star in the western sky. Looked it up and it is Venus. Look out to the west about an hour after sunset.
The night sky this week.
Venus
Appearing as a brilliant star-like object, our sister planet adorns the evening sky low above the western horizon about one hour after sundown. The planet is now virtually full (85-percent sunlit), and through a telescope displays a tiny disk 12 arcseconds across.
For such a dazzling naked eye sight, Venus is one of the most profoundly disappointing sights in the telescope. The planet's surface is perpetually obscured by an extremely thick atmosphere, so any observations will be limited to details discernible in its rather bland covering - slightly brighter or darker areas, or irregularities in the terminator.
It has been found that the top of the atmosphere lies around 250 miles above the surface, and that the upper clouds have a rotation period of only 4 days. The upper clouds lie at an altitude of 45 miles, and there are several definite cloud-layers, though below 20 miles the atmosphere is relatively clear and calm. The atmosphere's main constituent is carbon dioxide, accounting for over 95 percent of the whole; most of the rest is nitrogen. The clouds are rich in sulfuric acid; at some levels there must be sulfuric acid "rain" which evaporates before reaching ground level.
Finder map - one hour after sunset, looking west.
The night sky this week.
Venus
Appearing as a brilliant star-like object, our sister planet adorns the evening sky low above the western horizon about one hour after sundown. The planet is now virtually full (85-percent sunlit), and through a telescope displays a tiny disk 12 arcseconds across.
For such a dazzling naked eye sight, Venus is one of the most profoundly disappointing sights in the telescope. The planet's surface is perpetually obscured by an extremely thick atmosphere, so any observations will be limited to details discernible in its rather bland covering - slightly brighter or darker areas, or irregularities in the terminator.
It has been found that the top of the atmosphere lies around 250 miles above the surface, and that the upper clouds have a rotation period of only 4 days. The upper clouds lie at an altitude of 45 miles, and there are several definite cloud-layers, though below 20 miles the atmosphere is relatively clear and calm. The atmosphere's main constituent is carbon dioxide, accounting for over 95 percent of the whole; most of the rest is nitrogen. The clouds are rich in sulfuric acid; at some levels there must be sulfuric acid "rain" which evaporates before reaching ground level.
Finder map - one hour after sunset, looking west.
