27 May 2009

Blue Neptune

A first for me: Early this morning before sunrise was the first of three conjunctions between Neptune and Jupiter. The rare "triple conjunction" started this morning with a close passage of Jupiter near Neptune in Capricorn. The separation was less than half a degree (less than a moon-width) and the difference visually between giant Jupiter and its four moons and blue Neptune was dramatic. Neptune looks essentially like a dim blue star through binoculars -- and is invisible to the unaided eye.

I had never taken the time to look for Neptune in the past. Because it is so dim and nearly impossible to resolve to anything but a pinpoint of light, I had never been motivated to seek it in a field of dim stars. But with Jupiter as my guide, it was an easy find and a magical moment to see those two solar system objects in one field of view. The alignment of two very distant planets - one 450 million miles away, the other almost 3 billion miles away - in a compact cluster less than half a degree apart was nothing short of remarkable. Now that the two planets have lined up once, they will soon reverse course and move in retrograde motion across the sky and will have the second conjunction on July 13th. Then they will return to prograde motion and have their final conjunction on December 20th. This long slow process is rare indeed, but as Jupiter speeds eastward away from Neptune after December 20th, it will soon arrive near to Uranus and will have a triple conjunction with Uranus starting in June 2010. I'll be sure to catch that one as well - because - yes, because I haven't ever seen Uranus either!

25 May 2009

Moon passing through Gemini and Leo

As we transition from spring to summer, during the early phases of the lunar cycle the Moon's path appears to jump out of the western twilight sky fairly steeply toward the zenith. Gemini is the zodiac constellation that appears highest in the sky compared to the 11 other constellations of the zodiac. Thus in springtime when the Moon passes through Gemini, it appears fairly high in the western sky. This week you can see the Moon on its journey first through Gemini, then briefly across Cancer, then into Leo and a flyby of Saturn.

I am fascinated by the daily lengthening of the minutes and hours of sunlight at this time of year. Each day the sun rises a minute earlier and sets a minute later. It's very interesting to watch the transition from sunset to dark moving later and later each evening. In addition to the timing of sunset, the location is also changing. The sun sets quite far north of west and the point of sunset continues to move north until the summer solstice.

15 May 2009

Jupiter in the morning

Jupiter and the Moon are going to share the southern sky during the early morning hours the next few days. If you are up before dawn look south-east for the waning Moon and bright Jupiter. On the 17th the two will have a close encounter that should be a pretty sight for the naked eye or through binoculars.

12 May 2009

Get Involved: the Search for Extraterrestrial Intelligence (SETI)

Astronomers, whether professional or amateur, inevitably ask themselves "are we alone in the universe?" It's a natural question to ask when you spend a lot of time looking into the sky, whether in pursuit of scientific research or in a backyard enjoying the view of a deep space object in a telescope. The term "Search for Extraterrestrial Intelligence" (abbreviated SETI) is the name for a collection of worldwide projects that are studying the universe and gathering data in the hope of answering the question "are we alone?"

Here in the Bay Area, the SETI Institute is hard at work on a broad range of scientific pursuits that support the mission of SETI, "to explore, understand and explain the origin, nature and prevalence of life in the universe. We believe we are conducting the most profound search in human history - to know our beginnings and our place among the stars." The SETI Institute is building a massive array of radio telescopes in Northern California, the first phase of which is already listening for signals of intelligent life every day.

The Director of SETI, Jill Tarter, recently was honored with the TED Prize given in February at the TED Conference. The prize brings visibility to the project and is propelling forward a major initiative to bring together a global community of technologists using social networking methods to collaborate on SETI. There is a blog on the TED website where you can follow the progress of the SETI Institute.

I am captivated by the work of the scientists and visionary leaders at the SETI Instititute and encourage others to get involved by learning about the Institute, becoming a member of TeamSETI, or volunteering in a greater capacity to support their efforts. And put your computer to work on the SETI@Home project.

11 May 2009

Near-Earth Astronomy: Iridium Flares

For quite a while I have been captivated by the sight of the International Space Station (ISS) whenever it is visible in the evening or morning sky. It is a big object, about 100 meters across and highly reflective. In the sky it looks as bright as Venus but it moves as swiftly as an airplane and in a very beautiful arc across the sky. Last week I was introduced to another near-earth satellite, actually a group of satellites known as Iridium Satellites. These are a collection of 66 communications satellites that circle the globe from a higher orbit than the ISS, but nonetheless light up quite brightly when viewed from just the right orientation. When sunlight glints off the antenna panels they create a very bright beam of light known as an "Iridium Flare."

I had never taken the time to look for one of these flares so I consulted a website known as Heavens Above (also permanently linked from this blog). There you can enter your location on a Google map and get a listing of the next 7 days of Iridium Flares. I did this and yesterday saw an amazingly bright flare from my front steps.

Iridium Flares are very localized events - that is, when a flare is visible at a particular moment and in a particular location, you won't see it nearly as bright (or at all) 10 or 20 miles away. So if you want to see one, take the time to carefully select your location on the map and then jot down the exact times and locations of the next few flares in your neighborhood. They are indeed impressive and you will be glad you took a moment to see one. They are astronomy - from my point of view - because you are looking carefully at the sky and seeing something that is outside of our own atmosphere.

07 May 2009

Thursday Nightlife at the California Academy of Sciences

I spent most of this evening in Golden Gate Park at the California Academy of Sciences. Several months ago they initiated a new program called Nightlife. From the Academy of Sciences website:

Every Thursday, the Academy is transformed into a lively venue filled with music, provocative science, mingling, and cocktails, for visitors 21 and older. Activities and performers change week to week.

The event has been selling out week after week and tonight was no exception. I am so impressed that literally thousands of San Franciscans show up to take in the science, the music, the food and drink, and the company of friends and neighbors. The Living Roof was my primary haunt because of the clear skies over San Francisco. The view was great this evening and there were three amateur astronomers on the roof with telescopes showing off Saturn and the nearly full Moon. Although I don't work for CAS, I could not help myself but to talk with guests while they waited in line to look through the telescopes. I shared my insights of the night sky, of what to look for in the telescope, of how far away these celestial objects are, and so on. I really enjoy doing this for people who show an interest in the sky - to enhance their experience and to impart some new knowledge of the universe.

No surprise, I am enrolling in the training program to become a volunteer at the CAS :-)