27 March 2009

My Astronomy Manifesto

I was honored to be one of the blog contributors for the "100 Hours of Astronomy" event. I wrote my philosophy on astronomy - not exactly a manifesto but still, a statement of intent. I hope you like it!

16 March 2009

Get involved: Earth Hour

On March 28th cities around the world will take part in "Earth Hour 2009" and you should too. This has grown from a small event that reached a few million people to a global event that should touch billions this year in a global effort to reduce light pollution by turning off unnecessary lights for an hour. It is good for the environment and of course, from my point of view, it is a way to start turn back the effects of light pollution - or at least enhance awareness of the problem as the International Dark Sky organization is doing.

The main task is to turn off unnecessary lights for an hour at 8:30 pm on Saturday evening March 28th. Around the globe, people will do this at 8:30 pm local time and if enough people do this we might be able to see an actual increase in star viewing because of a bit more darkness!

Here in San Francisco a small but growing group of concerned citizens are working to raise awareness of light pollution and are looking into reasonable alternatives for the City of San Francisco to lower light levels and use outdoor lighting more intelligently - and bring the stars and galaxies back to our parks and backyards - while at the same time actually improving safety.

Check the Earth Hour website for more details on happenings around the globe. And check back on my blog for more information about local San Francisco events including a star party that I will be joining. Click here for photos from an interesting National Geographic article on light pollution.

15 March 2009

Venus in the evening and the morning: a rare event indeed

During the month of March we will have a very rare opportunity to see our nearest planetary neighbor, Venus, when it is at its closest approach to Earth and when it will be visible both in the morning and evening skies. This is indeed a rare event, something which happens every 8 years.

It takes a lot of factors to make it possible to see a planet both at sunset and sunrise. Without going into too much detail, planets and the Moon are all located along the "ecliptic", the band in which the moon and planets all move each month and year in their journey through the Solar System. Because they are on this band, it is very difficult for an evening object (something you see just after sunset) to also be visible early the next morning before sunrise. Because of the unusual geometry of this particular alignment ("conjunction") of Venus, we have the possibility to see it twice in the same day from March 20th through the end of the month. You will need to invest some time to locate the extremely slender disk of Venus and you will be helped substantially using binoculars, but the sight should be impressive and it is one of those unique astronomy challenges that really gets me excited. You will want to use a detailed chart and the advice of a professional astronomer such as Tony Flanders of Sky & Telescope Magazine. Best of luck!

14 March 2009

Join me for 100 Hours of Astronomy

When I get a chance to speak to a group about astronomy, be it a group of friends at a party or the radio audience of KFOG in San Francisco, I am always hoping to ignite a spark of interest in people. I want for friends and neighbors to take a minute to connect with the world around them. In this year, the International Year of Astronomy, I am increasing my outreach to ensure that anyone who meets me knows about my passion for astronomy and gets a little bit of it for themselves.
One way this will be happening soon is during the "100 Hours of Astronomy" event being put on by amateurs and professionals around the globe from April 2nd through 5th. You will be able to find me on the evenings of Thursday April 2nd and Friday April 3rd at Lands End in San Francisco along with other enthusiasts showing off the wonders of the night sky. Think of it as a giant Star Party for everyone who wants to get involved. I'll set up each evening in the parking area just above the Sutro Baths. I hope to see you there.

12 March 2009

Get involved: GLOBE at Night

Here is a way to try out something that will broaden your horizons and get you to see the stars in a whole new light (pun intended!) - while also working with thousands of other observers around the world. The GLOBE at Night project is attempting to raise awareness on the issue of light pollution and is gathering data from around the world - - including your backyard. The project website invites you to take a very close look at the constellation Orion between March 16th and 28th and note how many of Orion's stars you can see by comparing your view to star charts on the website. I've never done this myself so I am looking forward to taking my kids out when the skies are clear over San Francisco. The whole thing should take about 5 minutes but the lessons learned will stay with you for a lifetime.

Happy Viewing!

04 March 2009

Was that the biggest Full Moon of the year in January?

I am sometimes asked questions about astronomy themes that people hear in the popular media. In January friends sent me links to articles about the "biggest full moon of the year" and they made special efforts to get out and see this particular full moon. What was all the fuss about? Was it worth it?

First this thought: I am as captivated as anyone with the Moon. It is our closest neighbor and it has so many things to offer if you are ready to put in the time to study it. Most amateur astronomers put their telescopes away when the Moon is full, but in fact there is much to see using a simple telescope or binoculars such as the beautiful, large craters Tycho and Copernicus, or the large seas such as the Sea of Tranquility (also known as Mare Tranquillitatis, where Apollo 11 landed).

Back to the "biggest moon" discussion: As the Moon makes its 29 1/2 day journey around the Earth, the path it follows is an ellipse. The average distance from the Earth is about 240,000 miles, but the actual distance of the Moon from the Earth at any given time in its orbit can range 12,000 miles closer or 12,000 miles more distant from the Earth. These two extremes are called perigee and apogee respectively, and when the Moon is at perigee it appears about 15% larger (from our Earth-bound point of view) than it does at apogee.

When the popular press reported the "biggest Full Moon of 2009" they were accurate, but the fact is that every lunar cycle (every 29 1/2 days) the Moon goes through at least one cycle of perigee and apogee and therefore it is, at some point on its monthly journey, as big as the biggest Full Moon was in January -- but the phase will be different each month, from near Full ("gibbous") to First Quarter to Crescent to New Moon and so on around the cycle. The next perigee is on April 1st when the Moon will be in the phase of First Quarter. So I strongly urge everyone to get out on April 1st to see the "biggest First Quarter Moon of 2009." You won't be let down!