If you often find yourself watching Geneseo’s sunsets, you may have noticed that there’s an evening star setting with the sun. This is no star. This is the planet Venus.
As we reach the middle of August, Venus reaches its greatest eastern elongation. This means that Venus will appear brightest and look far enough from the sun for optimal viewing.
After looking west over the Genesee Valley on August 17 at 8:10PM for the sunset, Venus will be shining brightly until it sets at 9:45PM.
Elongation occurs when a planet is at its biggest angle between from the Sun when measured from the Earth, and happens every nine months. This can only happen with planets between the Sun and Earth, so you’ll notice this phenomenon with Venus and Mercury.
There are also two variations of greatest elongations: eastern and western. Eastern or western is denoted by the direction of the planet in reference to the Sun. If the planet is seen after sunset, it is in its eastern elongation, like Venus. If the planet is visible before sunrise, it is in its western elongation.
For another viewing opportunity, Mercury will be at its greatest western elongation on August 26 before the sun rises.