Thursday, November 17, 2011

Venus Visibility

Venus's visibility is high. Venus is the brightest object in our skies (apart the sun and the moon). Since Venus's orbit is inside the Earth's orbit, Venus is never far away from the Sun (distance in the apparent skies), so it is visible either before sunrise in the east or just after sunset in the west. When Venus is in its largest distance from the sun (which is about 44 degrees from the sun), it will be visible for 2-3 hours. Venus is so bright, that it can be mistaken for an airplane, and often is seen as a diamond and not just as a point. Venus is so bright that it can be seen in the midday. In order to do so, you should know where Venus is (quite easy with today's smartphone apps) and stand in the shade so the sun will not disturb you. It is also a good idea to check when Venus is near the moon and try to locate the moon first. You will see a very bright white dot against the blue of the skies like in the photo below (which was taken when the moon was nearby as well). The following photos were taken around noon.
Venus and the Moon
Venus and the Moon Venus is the white dot in the clouds
While the clouds give some atmosphere to the photo, here is another example from the same day, where Venus is not behind any clouds. In this photo you will see that Venus looks brighter than the moon . Although the moon is brighter than Venus, Its total brightness is distributed over a larger area. Venus's brightness is concentrated in a single dot.
Venus and the crescent moon
Venus and the crescent moon

When evening falls, Venus become much more visible (Its brightness does not change, but it is easy to see it against the darker background). The next photo (click on the photo to enlarge it) shows the very thin moon crescent and bright Venus about 30 minutes after sunset. I've also marked the very pale dot of Mercury in the middle!
Venus, Mercury and the crescent moon
Venus, Mercury and the crescent moon