Saturn, the Lion, the Moon

Saturn is visible high in the evening sky for the coming months. The ringed planet is a gem to see through a telescope so if you have a telescope now is the time to get it out and take a look at one of the most impressive sights in all of the universe.

Saturn, like all the other planets and the Moon, travels around the Solar System in a path called the Ecliptic. This path extends through twelve constellations known as the Zodiac. Saturn, which takes nearly 30 earth-years to travel around the Sun once, spends about two and a half years moving through each sign of the Zodiac and is presently moving gradually eastward through Leo the Lion. This constellation is a favorite for many because its shape is quite distinctive and resembles a Lion in the sky with its furry mane and head pointed to the west and its tail and hind quarters to the east. As you can see in the diagram, Saturn is below the constellation and to the left (east) of the bright star Regulus.

Cosmic Juxtaposition: Pleiades, Mercury and Moon

The next three evenings present a visually stimulating lineup of objects near and far in a juxtaposition that is just right for binoculars. You will need a clear western horizon so I have my fingers crossed that conditions permit this at Ocean Beach in San Francisco, but wherever you are, the diagram shows the close alignment of Mercury and the Pleiades star cluster and the daily motion of the Moon through this configuration. On Saturday 25th the challenge will be to spot the very young Moon. On Sunday 26th the sight of all three things in one binocular-field-of-view. And if you get a weather trifecta and see this three nights in a row, then Monday 27th you will have seen just how far the Moon *and* Mercury move in 48 hours - and I think the results will surprise you.

Happy Viewing!

A Dawn Spectacle: Moon Occults Venus on Wednesday April 22

Wednesday morning in the pre-dawn skies we have a rare opportunity to witness a very unique spectacle, an occultation of the planet Venus by the Moon. Think of it as an eclipse of Venus, a brief time when the Moon's orbit blocks out brilliant Venus for about an hour. From here in San Francisco the Moon and Venus will just be rising above the eastern horizon around 5:00 am and by approximately 5:11 am the Moon will close in and cover the planet. As the Moon rises and the earliest light of dawn arrives, the Moon will reveal Venus again at approximately 6:05 am. For more information, click on the image.

I am particularly fond of this special event for it was during an occulation of Venus that I first became interested in astronomy as a young boy. So my advice is to take a few minutes to experience this rare and impressive sight. It might just move you too.

April Mornings above Golden Gate Park

The next few mornings promise rewarding sights if you are up before sunrise. For me, this is the view when I go out to get the morning newspaper. I have a good south-eastern view and I find the waning Moon to be an engaging beacon above the trees of Golden Gate Park. As the Moon rises later each day, it sweeps past three planets now visible in the morning sky, Jupiter, Venus and Mars, and it appears lower and lower each day until it is lost in the glare of the Sun at the end of next week. The illustrations show how much the Moon moves from one day to the next -- a little over 12 degrees. Why is that? You just need some simple division to get the answer yourself: The Moon travels 360 degrees in each orbit around the Earth, and it takes 29 1/2 days to circle the Earth once (from our Earth-bound perspective)

Watch This: 400 Years of the Telescope

A new astronomy documentary has arrived and is being featured on PBS this week. In the Bay Area you can see the new film "400 Years of the Telescope" on KQED Channel 9 on Tuesday April 14th at 9:00 pm. From the "400 Years" team, here's what you can expect:

In 400 Years of the Telescope, viewers take a visually stunning journey from Galileo's first look at the cosmos in 1609, to today's thrilling quests to discover new worlds and glimpse the formation of the first stars after the Big Bang. Writer and producer Kris Koenig traveled the globe, interviewing leading astronomers and cosmologists against a backdrop of the world's greatest observatories, to create a vivid film that presents the human quest of the past 400 years to understand the structure and nature of the universe. 400 Years of the Telescope is an official product of the International Year of Astronomy 2009.

San Francisco Star Parties - photos

On April 2 and 3 as part of the "100 Hours of Astronomy" event, I took part in two of three nights of star parties in San Francisco. It was fun and I enjoyed meeting new people and sharing the sky with them. I'll be posting more of this on the "100 hours" website next week. Meanwhile, here are two photos (courtesy of Rick Prelinger) that he took with a simple camera phone and a time lapse exposure. With a bright moon directly overhead, the scene was lit exclusively by moonlight (well, ok, with the exception of some headlights in the parking lot) and looks strangely surreal but the images capture the essence of the star party. You can see some stars in the images. Very cool!

San Francisco Star Parties - for 100 Hours of Astronomy

The San Francisco Amateur Astronomers are sponsoring three upcoming star parties over the duration of the "100 Hours of Astronomy" event this week. For those of you in San Francisco stop by Lands End on April 2-3-4 to take in the sky and meet local astronomy enthusiasts. The events starts at 7:30 (just at sunset) but come anytime until 9:30. Some of the SFAA members might stay past 9:30. The area for telescopes will be at the north end of the parking lot where the Lands End trail starts. I hope to see many people there. Be sure to dress warmly - it gets very cool there in the evening.

If you live outside of San Francisco, check the "100 Hours" website for other events happening in your area.