23 August 2010

Perspective of the Solar System

After weeks of foggy skies in San Francisco, the sky has started clearing, yielding spectacular sunsets and sky shows at Ocean Beach. I have been writing about (but not seeing much of) the amazing sight of the planets dancing across the evening sky. With the clear skies, the view was great, showcasing Venus and Mars very close together, with Saturn just to the lower right and the bright Zodiac start Spica (in Virgo) just to the upper left.

This configuration traces a curve in the sky and if you have a clear southern horizon you can "connect the dots" from this cluster of stars and planets to the south where bright Jupiter dominates the sky. Beyond that, the Moon is slicing across the lower southern sky, providing the observer with a nice visual of the Ecliptic, the line of the planets, Moon and Sun. This is a great way to visualize the path of the planets in the Solar System when you look out from our Earth-bound perspective.

Over the coming months, Mars and Saturn and eventually Venus fade, but the giant planet Jupiter will be dominating the Fall skies.

11 August 2010

Perseid Meteor Shower 2010

The Perseid Meteor Shower reaches its peak this week and the timing is very good for a fine display of meteors. Every year when the Perseids come around, the biggest concern is the Moon. Its beautiful light is a welcome sight to many, but for amateur astronomers and anyone wishing to see more than a few meteors, moonlight can ruin an otherwise-perfect evening of viewing. This year the Moon is very young during the Perseids and sets not long after sunset, leaving a dark sky for the shower.

The Perseids peak on the nights of Thursday 12th and Friday 13th, with best viewing on Thursday night / Friday morning. You can get detailed information on the Sky and Telescope website or on numerous other web resources.

The best way to see the meteor shower is to find a dark location, give your eyes plenty of time to adapt to the darkness, and be prepared to stay up late (or get up early). Meteor showers are almost always best viewed after midnight when the Earth is powering directly into the meteor stream and the rate increases substantially. The Perseids appear to originate in the constellation Perseus which is in the east after midnight, but that does not mean you have to specifically look east to see the meteors. Lying on a blanket facing directly overhead gives you the most expansive view and you can see meteors coming from the east or passing overhead toward the west. Meteors are wonderful, fast, elusive wonders and you simply need to be warmly dressed, in a place where you can see as much of the sky as possible without light distractions, and patience. I wish you clear skies and a great night or two observing.

02 August 2010

Trio of Planets

The evening sky brings us a trio of planets in a close grouping this week. The bright beacon of light, Venus, shines brightly and moves quickly from night to night, especially by comparison to the slower-moving Mars and Saturn. The image shows the view on Sunday August 8th, so looking at this earlier in the week you will find Venus lower and to the right of the other two planets, and after the 8th you will see Venus glide to the upper left of the two planets. We are witnessing the motion of Venus along its orbit around the Sun, moving much more quickly from our vantage point on Earth than Mars and Saturn. Venus will continue to dominate the evening sky for many weeks to come.