05 July 2010

Star-and-Planet Drama

The evening sky over the next few weeks offers a study in the changes that take place in the sky along the path of the Moon and the path of the planets. This is exciting to watch and helps to unveil some of the intricacies of the Solar System, something you can see right from your own backyard. For quite a while now I have been particularly fond of sharing the path of the planets across the sky (the "Ecliptic") while conducting star parties and giving astronomy talks. I find that the ability to visualize this band across the sky is an important one for those who wish to have a basic understanding of the motion of the planets across the sky. And for several months the bright planets, a collection of bright stars, and the monthly sweep of the Moon across the sky have provided a perfect laboratory for learning. This month is no exception.

Shortly after sunset there is an excellent parade of planets and stars easily visible as the glare of dusk fades, starting with brilliant Venus in the west, and then in succession from west to south are Regulus, Mars, Saturn and Spica. These bright objects show the line of the Ecliptic.

At the end of this week there is a total solar eclipse (unfortunately not visible
from the San Francisco Bay Area). The eclipse comes at the middle of an Eclipse Season and as such, the Moon follows a descending path below the Ecliptic in the days that follow the eclipse, in particular from the 12th to the 17th of July. As it moves from day to day, it swoops just below the Ecliptic and makes a pleasant arc across the southern sky below Venus and Regulus, then Mars, then Saturn and then Spica.

And in addition, we are just coming into a period of time when fast-moving Venus has close encounters with the other planets and stars along the Ecliptic, starting with a close encounter of Regulus on the 9th of July. More drama to come in the next few weeks -- stay tuned!

1 comment:

Sidewalk Universe said...

This was a pretty pairing. Mars Saturn conjunction will be fun too!