Mercury disappearing from View

Mercury is today setting 26 minutes after the Sun has disappeared below the horizon . Actually when the Sun does set,  Marcury is only 4.4 degrees above the horizon so it is safe to assume that it is pretty much impossible to see Mercury from Sydney at the moment.

Mercury 19 April 10 (Click to Enlarge)

It has being very interesting watching Mercury recently. If you look at the daily chart above which shows when planets are visible, you will see that tonight only 10% of Mercury is lit by the Sun. This is in contrast to the other planets which  all are over 90 %  illuminated. Does anyone know why Mercury is the only planet to have so little illumination unlike the others?

On April 27. Mercury will not be illuminated by the sun at all until May 1 when the Sun slowly begins to shine on the planets surface again. On the first day of May, Mercury will be rising in the east just 15 minutes before the Sun.This will change quickly over the first week of May as Mercury will rise one hour ahead of the Sun on the 7th of May.

So Mercury is not visible in the evening at the moment but it will not be long before we will see Mercury again in the early hours of the morning.

If you are interested in seeing what Mercury would look like tonight, have a look at the picture above.

~ by sydneystargazers on April 19, 2010.

One Response to “Mercury disappearing from View”

  1. This picture will demonstrate why Mercury is only illuminated 10% (taken from a new iPhone app called SolarWalk). As you can see, Mercury is relatively in line between us and the sun, hence we are only seeing the edge of its illuminated face. A large amount of the illuminated face of Venus is visible to us due to its angle between us and the sun. For the planets behind us, the sun bounces off them and straight back at us, so we’ll see the entire illuminated face. hope this helps.

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