Quadrantid Meteor Shower 2012 - peaks January 3-4

The annual Quadrantid Meteor Shower peaks on January 3rd and 4th, with the possibility to deliver a great show for viewers across North America. The Moon will interfere in the early stages of viewing, but despite that, the shower should be a good one.

Meteor showers typically are strongest after midnight, when the Earth's 'front face' is moving directly into the meteor stream as the Earth moves in its orbit around the Sun. In addition, many meteor showers have a peak where the meteor stream is strongest. This year, North America is well positioned for the Quadrantid peak. For those of us on the west coast of the US, the peak should start around 11:00 pm on Tuesday January 3rd, and continue into the morning hours of Wednesday the 4th. You can read more about the meteor shower peak in an excellent article from the American Meteor Society. The Quadrantid 'radiant' is near the handle of the Big Dipper, which will be high in the sky in the morning hours.

Viewing the shower is easy. From 11:00 pm until 2:00 am (west coast time), face east as the radiant rises and climbs into the night sky. Later in the night, after 2:00 am, the Moon will be low and then set, and the best view will be directly overhead, ideally lying on your back in a dark location with a sleeping bag and warm clothing - it will be cold! In San Francisco, I find that I can see many meteor showers from my own backyard, despite being in a big city. The two important things to do are (a) find a location where streetlights and houselights are not shining in your eyes, and (b) allow for 10-15 minutes to fully dark-adapt to the night sky, and then you can expect to see meteors. If you just look outside for 1 or 2 minutes and don't see any, you should not be surprised. Meteor viewing requires patience and a little bit of planning. But the investment of time is worth it, because meteors are such beautiful cosmic things. I wish you clear skies and good viewing!

Image courtesy EarthSky.

A Beautiful Evening Pairing of the Moon and Venus

The young crescent Moon will be paired up with the brilliant evening "star" Venus on Monday evening, creating a stunning visual in the sunset sky. The monthly cycle of the Moon always brings beautiful patterns as the daily travel of the Moon along the ecliptic brings it near to other objects. But when the Moon is paired with Venus, the next-brightest object in the sky, the view is riveting, especially when we have clear skies and a view to the west. I saw a similar pairing last month while traveling in Southern California, a magnificent Moon-Venus pairing in the glow of sunset to the west while out walking in the warm November air. This time, I'll be watching from the cool coast of San Francisco, but the view should be no less impressive. If skies permit, look west and enjoy this spectacle, all the more impressive if you view through binoculars or a telescope.

As the Moon passes through the Zodiac constellation Capricorn, it will also pass near Neptune on the 27th, then onward along the ecliptic into Aquarius and near Uranus on the 29th, heading toward a fly-by of Jupiter in Aries on January 1st. You'll need a telescope to see Neptune and Uranus, but not Jupiter, the other dominant object in our night sky right now.

Image courtesy Sky & Telescope Magazine.

The Longest Night and the Early Morning Darkness

Winter Solstice brings us a long night, but not the latest sunrise. That comes in a couple weeks, for reasons too complex to explain here. The advanced student can follow this link to the EarthSky blog, or this one to Astroprofs. With the late sunrise, around 7:20 am this week in San Francisco, we have plenty of darkness in the morning to see the waning crescent Moon pass by some very fine morning stars and by the planet Mercury.

Morning skies offer a particularly beautiful view of the heavens, as the atmosphere is generally calm and often the sky clears as moisture and dust settle. Some of the bright urban lights that were glowing in the evening are switched off late at night.

The Big Dipper is high in the north-east by early morning as winter starts, and the brilliant winter constellations and stars punctuate the view overhead and to the west.

Weekdays I don't usually have time for a full viewing session early in the morning, but that doesn't stop me from stepping outside for a brief look around the sky. Try this for yourself when you first get up. You'll be impressed with the view, even in a big city like San Francisco.

Image courtesy of Sky & Telescope.

Geminid Meteor Shower 2011

The Geminids peak the nights of December 13th and 14th this year, one of the better meteor showers of the year. Unfortunately for 2011, most of the Geminids will be nearly invisible due to the very bright Moon that dominates the late night and early morning sky, when the Geminids are at their best.

The effect of a bright Moon on a meteor shower was vividly illustrated to me during the Total Lunar Eclipse a few days ago. I was at Ocean Beach on the west coast of San Francisco for the eclipse in the early morning hours. Facing west, Gemini was directly in front of us, dominating the western sky. As the brightness of the Moon faded, we began to notice meteors -- we were seeing some very early Geminid meteors, facing the radiant directly. I was very surprised at the stark contrast in meteor visibility from Full Moon before the eclipse started, to an ever-increasing amount of meteors over a very short period of time as the Moon, in effect, when through all of its phases in about 60 minutes. It reaffirms for me the huge difference a moonlit night makes when watching a meteor shower.

Although the meteors will be diminished for the Geminid Meteor Shower in 2011, I'll still take a look, since a big shower like this has plenty of bright meteors that pierce the night despite moonlight. If you want to read more about the Geminids, check out this interesting article about the Geminids radiant, from Earth Sky, from the LA Times, or this one from NASA Science News.

Image courtesy EarthSky.

Total Lunar Eclipse 2011 - in San Francisco

Saturday morning, we will witness a Total Lunar Eclipse visible from western North America and regions across the Pacific Ocean. In San Francisco, we will have a dramatic early morning spectacle of the fully eclipsed Moon setting on the Pacific just as dawn breaks. As with any total lunar eclipse, the Moon's surface will be completely covered by the dark 'umbral' shadow of the Earth, but it will remain visible, taking on an eerie appearance of rusty red, or deep grey, or a mix of colors. Every eclipse is a little bit different, so we wait in anticipation to see what happens Saturday morning.

The circumstances of this eclipse are outlined in detail in this informative Sky & Telescope article, and this excellent NASA Science News article.

The timeline for San Francisco (and the entire pacific time zone) are: start of eclipse at 4:45 am, start of totality at 6:05 am, and end of totality at 6:57 am. The glow of the dawn sky will emerge in the eastern sky shortly after 6:00 am, so the Moon will be in total eclipse as the sky begins to brighten, and by the time the Moon exits the total phase, the sky will be fully lit in advance of the sunrise at 7:13 am.

What does all this mean to the casual viewer? You will experience the best views and the most drama from 4:45 am until 6:30 am, when the Moon gradually changes from full to completely eclipsed, and the skies are dark enough to appreciate the beauty and subtlety of the lighting and color of the lunar surface. And as the Moon's brightness is attenuated as the Earth's shadow creeps across the surface, the backdrop of stars will begin to shine more brightly by contrast, revealing the wonderful winter sky at its best, with the constellations Taurus, Orion and Auriga around the Moon, and some of the most beautiful, bright stars in the entire night sky punctuating the skyscape.

I welcome the public to stop by Ocean Beach on the west coast of San Francisco for an early-morning star party, where I and others from the San Francisco Amateur Astronomers (SFAA) will have telescopes set up for public viewing. We will set up at the beachwalk just across from the Beach Chalet restaurant on Great Highway, starting around 4:30 am. But heed the advice of Deborah Byrd in this EarthSky article, and wear very warm clothes. You'll be glad you did, as the winter chill is quite intense just before sunrise.

Viewing all 5 Visible Planets in one night

As the nights grow longer and the skies darker, we have the chance for the next few weeks to see all five planets visible to the naked eye in a single night. Of course, there are seven planets in our Solar System (not including Earth), but two (Uranus and Neptune) are just too faint to see without optical aid. However, the rest (Mercury, Venus, Mars, Jupiter and Saturn) are spread around the entire sky, adding a lot of brightness to our already-shiny Autumn and Winter skies. This article in the science blog EarthSky is an excellent guide to help you find each planet. Of course, to find Jupiter and Venus you need little guidance because they are so bright, but Mercury, Saturn and Mars will be easier to find with some assistance from a sky map.

And if you are ready to look deeper and see all 7 in one night, here is a chart to guide you to Uranus and Neptune. They are both just west of Jupiter, in the constellations Pisces and Aquarius.

Image courtesy NASA.

Saturn Returns

Saturn has returned to the morning sky, rising higher each day shining in the east before sunrise. It is near the bright blue giant star Spica, in the constellation Virgo, and this week is graced by a visit from the Moon, creating a beautiful grouping on the morning of November 22nd.

Saturn and Spica are an interesting pair to compare. They are a contrast in color, with Spica shining a deep blue, and Saturn with a yellow-white tinge. Spica is 260 light years away, distant compared to many other bright stars in the evening sky, but being a giant star, it emits enough light to be the 15th brightest star in our night sky. Saturn is 80 light minutes away, a giant planet by Solar System standards, but due to its distance it never shines as bright as other Solar System objects such as Venus and Jupiter. But Saturn still captivates all who see it through a telescope because of its impressive ring system, making it a welcome target for any star gazer.

Image courtesy Sky & Telescope Magazine

Leonid Meteor Shower 2011

The Leonid Meteor Shower peaks on November 17th, bringing fast meteors to the late night sky. This shower is generally a good one for stargazers, but the glare of the waning Moon will hide some of the fainter meteors. Nonetheless, a meteor shower brings all kinds of meteors, faint and bright, long-tailed streaks and short blips of light, so with some commitment and a dark sky, you will be rewarded with at least a few good meteors if you take some time to look.

Get a sleeping bag, comfortable chair or pad, and enjoy the sight late on the night of Thursday 17th into the morning of the 18th. The radiant of this eclipse, the constellation Leo the Lion, is above the horizon after 9 pm and high in the sky after midnight, and although the namesake constellation appears to be the "source" of the meteors, in fact the Leonids will be visible in every direction, so the best view is to simply look straight overhead. I'll give it a go from my backyard here in San Francisco, a nice way to close out my birthday :-)

This excellent article in The Universe Today provides a lot more backgound information, as does this article from National Geographic.

Image courtesy Stardate.org.

An Asteroid Makes a Near-Earth Approach - YU55

We have a special event coming our way, literally. An asteroid by the name of YU55 will speed near Earth on Tuesday 8th, perhaps even becoming visible for those with a good telescope and a clear view to the west. David Perlman's article in the San Francisco Chronicle includes some very helpful information how to find this, as does Kelly Beatty's writeup in Sky and Telescope.

Track of asteroid YU55

This is a fairly rare fly-by of an asteroid. There are 1000s of "Near Earth Objects" (NEOs) being tracked. Tiny objects like meteors are commonplace, impacting Earth daily, and causing no harm as they burn up in the atmosphere. But the NEOs are larger, potentially causing considerably greater harm if they were to collide with Earth. Happily, all NEOs that are being tracked at this time are not on a collision course with us. YU55 will pass quite close by cosmic measures, within the orbit of the Moon. At 1/4 mile in size, an impact by YU55 would cause major damage on Earth, but we need not worry. And the next close fly-by of an asteroid is not expected until 2028, with a similar 'miss by a mile' outcome. Sleep well!

Jupiter at Opposition -- closest approach for 2011

The Autumn evening sky is being dominated by one bright, shiny object: the planet Jupiter, which will be a highlight for several months in our skies. On October 28th, Jupiter reaches "opposition" in which it is in a line with the Earth and Sun (and no, that is not what has been causing the recent earthquakes in the San Francisco Bay Area!).

Image Courtesy NASA

When Earth travels around in its orbit, approximately every 13 months we have a close encounter with Jupiter. When we do, the gas giant looks impressive with or without a telescope. Without a telescope, Jupiter is extremely bright, easily 50 times brighter than the brightest stars in the sky right now. It rises due East just after sunset, and remains visible the entire night. Through a small amateur telescope, Jupiter is a fine target, easy to locate and impressive with bands across its disk and the four Galilean moons shining brightly. Now is the time to get out a telescope or binoculars and share the brilliance of Jupiter with someone.

KFOG Broadcast - October 25, 2011

I was a guest on a live broadcast with the KFOG Morning Show today, talking about Jupiter, things to see in the Autumn night sky, the Pleiades, meteor showers, and the Bay Area Science Festival. The DJs on the Morning Show are an interesting group, and the conversation is always lively. Click here to listen.

The Changing Sky: Mira, a Variable Star

When observing the night sky, I enjoy the slow changes of the seasons and the stars as they arrive into the evening sky. The Moon and planets change their positions regularly, sometimes quite quickly. And transient events such as meteor showers and eclipses bring some drama to the sky. But the backdrop of stars is supposed to be constant and unchanging. And that brings me to the motivator for this blog post, the variable star Mira.

Stars have billion-year life cycles, so for us to witness a star's brightness changing over days and weeks is a rare thing. Astronomers study this special class of stars that regularly vary in brightness, and there is an association, the American Association of Variable Star Observers (AAVSO) that collaborate on research in this field. There's even a cool iPhone app that developer John Rachlin introduced me to. It's called Variable Stars, and it is free.

Mira is a well known variable star, and lately it has been changing its brightness very fast and over an extreme range, so that this star that is normally invisible to the naked eye is suddenly visible in the evening sky. I stepped outside this evening and found it near Jupiter, just a "thumb and a little finger away" as described by astronomy writer Tony Flanders in this Sky & Telescope article. I'm pleased to have found this special star that is now 1000s of times brighter than usual. If you feel up for a challenge, try to find it tonight.

Image courtesy of Sky & Telescope Magazine.

Orionid Meteor Shower 2011

The Orionid Meteor Shower peaks for the next two mornings, October 21 and 22, as the Earth passes through a debris stream left by Halley's Comet. Like all annual meteor showers, the Orionids occur at the same time each year because the Earth, in its 365-day trip around the Sun, passes through areas of increased debris, leading to a much more focused period of time with meteors flying into Earth's atmosphere and creating those beautiful streaks of light that magically light the sky for a moment and then vanish without a trace.

The name Orionids tells us that the meteors in this shower appear to emanate from the constellation Orion, the beautiful winter sky constellation. But like the best meteors in any shower, you won't see Orion until after midnight as it rises out of the east. Meteor showers are best observed between midnight and sunrise, when you are viewing meteors entering our atmosphere on the 'front face' of the Earth. Given that sunrise is quite late this time of year, take advantage of that and get up just ahead of dawn's light, around 6:15 in the San Francisco Bay Area.

Image courtesy of Earth Sky.

Brilliant Moon and Jupiter

The Full Moon dominates the night sky this week, lighting the Autumn landscape and making its presence known as the soft grey glow of moonlight washes out all but the brightest stars in the sky. But even as the stars take a back seat in the night sky, the giant planet Jupiter shines steadily next to the Moon, undiminished by the intense glow of our nearest celestial neighbor.

Jupiter is nearing "opposition" in which it is at its closest approach to Earth for 2011. That means that it is also at its brightest, outshining all other celestial bodies in the night sky right now, except the Moon. For the next few nights as the Hunter's Moon passes near Jupiter, your attention will be drawn to the dazzling brightness of the largest planet in the Solar System. And once the Moon has moved into Last Quarter phase next week, Jupiter will remain steadfast in the evening sky, waiting for you to find it in binoculars or a small telescope. Take a moment and look up close if you have not seen Jupiter up-close. It's a worthy (and easy) target.

Image courtesy of Sky & Telescope Magazine.

Get Involved: Star Parties and Astronomy Lectures

There are many ways to get involved with astronomy. No matter where you live, you can find local clubs and events using the Night Sky Network website. Just about anywhere you go, you'll find a friendly astronomy club ready to welcome a new guest or member.

In the San Francisco Bay Area, we have a wealth of resources. As a member of the San Francisco Amateur Astronomers (SFAA), I always recommend the monthly lectures at the Randall Museum in the City, open at no charge to the public (next lecture on October 19th). The California Academy of Sciences has an excellent lecture series, the Benjamin Dean Lecture Series, focused on astronomy topics (next lecture on October 17th). And in the greater bay area, you'll find things happening at The Lawrence Hall of Science in Berkeley, the Chabot Space and Science Center in Oakland, Foothill College (lead by award-winning Professor Andrew Fraknoi) in Los Altos Hills, and more.

I take part in a few specific events. One of my favorite places to show off the night sky is at the weekly NightLife event at the Cal Academy in Golden Gate Park, every Thursday night. When the skies are clear, I can be found on the Living Roof showing off the skies with a trusty laser pointer, alongside Academy staff with telescopes pointing at the Moon, Jupiter, or other objects of interest. It is an excellent place to have fun and learn some new things about the night sky.

On November 5th, I'll be working with Tucker Hiatt of Wonderfest during the Bay Area Science Festival with a star party on Mt. Tamalpais in Marin County. We're calling the event "Nekkid-Eye Nightscape," and it will follow a lecture called The Milky Way as Dark Matter Laboratory. Tucker and I will give an introduction to the night sky, showcasing the best and the brightest objects in the Autumn Sky. After the lectures, the SFAA will be there with wonderful telescopes to show off the night sky up-close and personal.

I hope to see you at an event sometime soon!

Mars passes through a star cluster, the Beehive

Our fellow planets in the Solar System are on the go, always wandering from place to place in the sky. The rocky planets (Mercury, Venus, Mars) move quickly, due to their closer proximity to the Sun, and their motion from day to day can be noticeable to the naked eye. The gas giant planets (Jupiter, Saturn, Uranus, Neptune) move more gradually but are nonetheless regularly moving against the backdrop of stars.

Mars, being our 2nd-closest Solar System neighbor, can appear to move quite considerably against the backdrop of stars from one night to the next. This week, it will pass through the constellation Cancer and in doing so, travel through one of the most well-known star clusters in the heavens, the Beehive Cluster. This will be a fine site even in city skies, but you will need binoculars to truly appreciate the view. Use the diagram to find this spectacle in the early morning sky, looking due east (just as I can see when I walk out my front door in the morning). Enjoy!

Image courtesy of Sky & Telescope Magazine.

Observing Twilight into Dusk

The minutes after sunset are some of the most beautiful, as the last rays of sunlight have disappeared and the sky begins its daily transition from bright blue to dark night. Looking west after sunset in the early days of Fall, you quickly find Arcturus shining due west, at first looking almost like an airplane that is moving very slowly. But soon you realize that this is a star, the third-brightest in the heavens. It is bright enough to shine clearly through the glow of twilight. The colors of the sky are changing rapidly during twilight, and the brightest stars soon emerge. In late September, you can easily find the fifth-brightest star in the heavens, Vega, directly overhead, guiding you to its neighbors Deneb and Altair in the Summer Triangle. And looking back toward the western horizon where Arcturus is shining, you can soon find the red supergiant star Antares shining low to the left (south-west) of Arcturus.

Later this week, the young Moon arrives in the twilight sky and passes near Antares. Find a nice western horizon, get comfortable, and enjoy the evening show that is pleasant, relaxing and beautiful to see.

Image courtesy of Sky & Telescope Magazine.

Autumnal Equinox: what do you see?

Friday September 23rd is the start of Fall here in the Northern Hemisphere, an event that has a specific moment, in this case 2:05 am on the West Coast. What happens at this moment? Can you 'see' an Equinox?

The two Solstices of the year, in December and June, get much more fanfare because they mark more dramatic transitions, both in the weather and in the slow change of the seasons. The longest day and shortest day of each year are much easier to understand. But the balance points in the equation of Earth's orbit, the Equinoxes, get much less attention because there is much less drama. But for me, there is a lot going on. From an observational point of view, there are three things to look for.

1. Sunrise is precisely due East and Sunset precisely due West, the two days of the year this happens.

2. The Sun is above the horizon 12 hours and below the horizon 12 hours (give or take a few minutes owing to the bending of light around the horizon as experienced at Sunrises and Sunsets).

3. The Sun's height in the sky at local noon, as measured in degrees above the southern horizon, is 90 degrees minus your latitude on Earth. For example, in San Francisco, we are about 38 degrees north of the equator, so the Sun's height at local noon is 90 - 38, or 52 degrees above the horizon.

There is a fourth, more subtle effect that happens around the time of the Equinox. The length of the day is changing most rapidly around this time. From the Summer Solstice to the Winter Solstice, the length of the day is continually reducing. On the Equinox, it is 12 hours, but from one day to the next the length changes about 2 1/2 minutes, around 16 minutes during the full week. That is noticeable, and if you get up at the same time each day, you are certainly aware of the changing light of the morning (or lack of light at this point in time).

The combination of the Earth's annual circuit around the Sun, the tilt of the Earth's axis, and the slightly eccentric orbit of the Earth around the Sun all contribute to very interesting effects that are most pronounced around the interesting transition points of Equinoxes and Solstices. Take a moment this Friday to appreciate what you are observing in the sky around you.

KFOG Podcast - Sep 16, 2011

Today's discussion with KFOG's Irish Greg features (a) the Milky Way in the Autumn Sky, (b) Fireball across Southern California, (c) new planets being discovered, and (d) the Supernova in the Pinwheel Galaxy. As always, it's good fun and in exactly 8 minutes, you'll be a more informed citizen scientist. Click here to listen.

Seeing the Supernova in the Pinwheel Galaxy

This week we can witness, first hand, a supernova that was just discovered in the Pinwheel Galaxy. A supernova is an explosion that marks the end of the life of a star, and usually these fiery events emit a great deal of light, brighter than anything else in the region for a short period of time. In this case, the star was a white dwarf of similar mass to our own Sun, but located 21 million light years away in a relatively-close galaxy. It is brightening and will be visible at its peak this weekend. However, you will still need patience and some kind of optical aid (telescope or binoculars) to see this.

The Pinwheel Galaxy (also known as M101) is located near the Big Dipper, quite high in the sky after sunset, so use the handle of the Big Dipper to help you located the Pinwheel Galaxy. Supernova discoverer Peter Nugent of Berkeley explains how to find the Supernova in this short video. To set expectations, the supernova will be a bright spot of light, similar to a star, so don't expect to see a vast region of glowing gas and colors, but nonetheless, you can be assured that the light you are seeing has been traveling for 21 million years directly from one of the most violent, cataclysmic places in our universe, at a moment just after a star's life has ended and new matter has been created. That is a good thought to ponder as you search for the supernova.

Good luck, and leave a message if you find it!

Big Astronomy Events in 2011 and 2012

Much of the time, I enjoy astronomy as a day-to-day hobby, taking in the sky often and enjoying the slowly changing view of the heavens. Sometimes, however, big events come along and obligate the observer to be present at a specific moment in time -- and also have the good luck of clear skies. We have a three such events in the coming year, and the San Francisco Bay Area is a good base from which to see these events.

1. Total Lunar Eclipse, December 10th, 2011.

This Lunar Eclipse will peak on Saturday morning, December 10th, just before sunrise here in San Francisco, meaning that if the skies are clear, the best view will be at the coast, where the Full Moon will be entering Total Eclipse just as it is setting over the Pacific. This will be impressive!

2. Annular Eclipse of the Sun, May 20th, 2012.

An Annular Eclipse, also called a "Ring of Fire" eclipse, happens when the Moon's disk fits "inside" the disk of the Sun, creating a ring of sunlight in the sky. It's not the same as a Total Solar Eclipse, but still a beautiful natural phenomena, one worth a trip to Northern California to see. The viewing path can be seen on the map in this link, and will pass near Redding and Mt. Shasta in Northern California. I'll be organizing a road trip with the San Francisco Amateur Astronomers (SFAA) to see this spectacle.

3. Transit of Venus, June 6, 2012.

A transit of a planet in front of the Sun is a rare and unusual event. This is one of a pair of transits of Venus, the first of which occurred in 2004, paired with this one in 2012. Then we have a 100-year gap until the next pair of transits of Venus. It will be a daytime event, of course, because we are going to see the tiny disk of Venus cross directly over the Sun's disk.

- - - - - - - - - - - -

I'll write about each of these events as the time draws nearer, so for now the main thing is to mark your calendar and do a bit of background reading by following the links in this blog post.

Image courtesy of NASA.

Seeing the Milky Way in City Skies

Summers bring pleasant viewing and a wealth of richness in the heavens. As the Summer Triangle rises and dominates the night sky, two of my favorite Zodiac constellations, Scorpius and Sagittarius, are visible deep in the southern sky. These big, bold constellations combine with the Summer Triangle to guide the urban star-gazer to the Milky Way.

For anyone who has seen the spectacle of the Milky Way in dark skies, you know just how profound this band of light looks as we view our own galaxy from within. And I know how disappointing it is after a few days in dark skies, to return to the city and realize that the beauty of the Milky Way is missing. But don't despair, for even in urban settings, you can still see many of the wonders of the Milky Way. To do this, you need to use a telescope or binoculars. Using Scorpius and Sagittarius as your anchor on the southern horizon, and the Summer Triangle high above, point the telescope or binoculars into the sky and move slowly from the south slowly overhead. You are looking into the Milky Way, and with the magnification and light-gathering of a telescope or binoculars, you cut through the glow of the city lights and enhance the light from space. And that will be a rewarding moment under the sky. No need for a fancy star chart or an iPhone app. All you need is a sense of wonder and a comfortable chair.

Perseid Meteor Shower 2011

Every Summer, the Perseid Meteor Shower raises the hopes of those interested in the night sky. Being one of the biggest meteor showers of the year, coupled with the fact that it takes place in the middle of Summer, it's not surprising that many look forward to it. However, some of the best viewing of the Perseid Meteor Shower in 2011 will be washed out by the Full Moon which coincides with the peak of the shower on August 12th and 13th.

However, all is not lost. Meteor showers vary in the duration, some lasting only a day or two with a clear peak moment, while others are spread over a longer period of time. Luckily, the Perseids are a longer-duration meteor shower, starting in late July and continuing through mid-August. Although the best viewing is on August 13th, the rate of meteors is already dramatically increasing by August 9th, and at that point in time this year, the Moon will not completely wash away the meteors. In fact, the Moon will be setting in the early morning, giving the dedicated meteor chaser an hour or two to see some fine Perseids before the first light of dawn. So my advice is to look on this schedule:

Early morning Tuesday August 9th: From 1:30 until 5:00 am.

Early morning Wednesday August 10th: From 2:30 until 5:00 am.

Early morning Thursday August 11th: From 3:30 until 5:00 am.

Early morning Friday August 12th: From 4:30 to 5:00 am.

These times are for San Francisco. The start time depends upon when the Moon sets, a bit later each morning. The end time depends upon the time of your local sunrise which may vary based upon your location. Use this website to determine your local conditions. In San Francisco, sunrise is shortly after 6:00 am, so I recommend viewing until 5:00 am at which time the first light of dawn will begin to interfere with viewing of meteors.

As is the case with every meteor shower, you need to get yourself in as dark a location as you can. In a big city, that means away from streetlights and in a spot with a big view of the sky. The meteors will appear to emanate from the East, but they will cross the sky in all directions, so your best view is lying on your back looking up. Get some blankets, stay warm and enjoy.

Image courtesy National Geographic.

Daytime Astronomy: Sunspots

Summer nights are short, making it more challenging to enjoy the night sky. But days are long, and the Sun often provides some fireworks to make things interesting. Right now, the Sun is moving into a period of maximum solar activity. Maximum solar activity comes as part of an 11 year cycle in which we observe peaks and valleys in the number and size of Sunspots, with the next peak in 2012.

Sunspots are areas on the surface of the Sun where magnetic fields have caused a disturbance in the normal flow of heat from the core of the Sun , and the areas appear black through Earth-based solar telescopes. These areas are "cooler" than the surrounding surface of the Sun (I'm not sure if the term "cooler" applies to the surface of a 10,000 degree star!), which means that Sunspots check in at about 5000 degrees. With a well filtered telescope, the areas look black by contrast to the extremely bright solar surface, known as the Photosphere. It's one of nature's truly fascinating phenomenon, and a wonderful thing to see directly through a telescope.

Our eyes are sensitive light sensors, and are completely overwhelmed when you look directly at the Sun. The heat from the intense radiation of the Sun can cause blindness in a matter of seconds. Fortunately we instinctly look away from the Sun and preserve our vision naturally. Experienced astronomers, however, can safely use solar filters on telescopes to cut the brightness of the Sun to the brightness of the Full Moon, and hence use a standard telescope with a filter to enable daytime astronomy. In San Francisco, you sometimes find a Sidewalk Astronomer showing off the Sun during the day. With the increase in Sunspots during 2011 and into 2012, I'll be out on the sidewalk doing this from time to time, and even if you don't have access to a solar telescope, you can check out Sunspots on the solar surface daily at the excellent website SpaceWeather.com. This website has some very amazing images of the Sun and other space-related "weather" items.

Remember: only view the Sun with properly designed filtering intended for safe solar viewing.

Image courtesy of SpaceWeather.com.

One Year on Neptune

We passed a landmark moment this month, the one-year anniversary of the discovery of the Blue Planet, Neptune -- one Neptunian-year, that is, which is 165 of our Earth-years. This gem of a planet is something that an urban astronomer has to work a bit harder to see, but once spotted it is a lovely blue point of light in the sky, a fine payoff for those with the persistence to track it down against the backdrop of stars in the heavens.

During its long trek around the Solar System, Neptune has periodic close encounters with other planets, as it did during the "Triple Conjunction of 2009" with Jupiter. However, this year it stands alone in the constellation Aquarius, more challenging to find because we don't get Jupiter as a beacon leading us to find the elusive blue planet. However, using this star chart, a pair of binoculars, a dark backyard location, and some patience, I am sure you can find it. I will be looking from time to time over the coming months as Neptune moves from the morning sky into the evening sky, scanning for its dim blue glow in the vastness of the night sky.

KFOG Podcast - July 8, 2011

Today was the final launch of the Space Shuttle. KFOG's Irish Greg and I talk about this historic event, about the wonders of the Summer night sky, and about upcoming Star Parties in the San Francisco Bay Area. All in 5 minutes! Listen here.

Moon in Descent

The Moon traces out a path across the sky that is slightly offset from the path of the planets and Sun (the well-known "ecliptic" path). The orbit of the Moon is inclined to the ecliptic by 6 degrees, meaning that at any given point in a month, the Moon might be found in the sky just at the ecliptic, or moving below the ecliptic (up to 6 degrees away from it), or above the ecliptic. As it travels in its 29 day journey around the Earth, the Moon passes through the ecliptic twice, once going down (descending node) and once going up (ascending node).

Since we just finished an Eclipse Season, the Moon's nodes are very near to the points in space where we have New Moon and Full Moon, enough that from the New Moon a few days ago, to the First Quarter Moon later this week, we see the Moon traveling past the descending node and moving well below the ecliptic. Visual proof of that this week comes in the form of Saturn and Spica (see image), both of which are nearly on the ecliptic. The daily change in location of the Moon shows us just where the Moon is in relation to the ecliptic, this week skirting just south (below) this imaginary line in space.

The Moon amid planets and star clusters

The morning sky this week will be rich with easy-to-spot celestial objects in the hour before sunrise. Find a good view toward the eastern horizon and use binoculars to enhance the view of Venus, Mars, the waning crescent Moon and two of the finest star clusters in the sky, the Pleiades and Hyades. I am looking forward to it!

Get Involved: Public Nights at Observatories, Stargazing at the Libraries and Museums

There are many ways to get involved with astronomy, and I want to provide some links to get you going places.

First, some places where I present astronomy. I am a regular at the California Academy of Sciences most Thursdays at their NightLife event. These are for adults-only (sorry, kids, they serve alcoholic beverages), and when the skies are clear, they have astronomers with telescopes trained on stars and planets, and me giving tours of the night sky. Stop by on a Thursday night and enjoy the Cal Academy, and journey up to the Living Roof for a personal tour from me.

I make special presentations for organizations around the Bay Area, this week at the Marina Public Library as part of the IMBIBE series of events being put on by the Friends of the San Francisco Public Library. Come join me Friday night, June 17th, to see our nearest star (with its fascinating Sunspots) up close, and when the skies turn dark, a close up view of other celestial highlights.

Local observatories and science museums hold regular astronomical viewing nearly every weekend. Chabot Space and Science Center has viewing on Friday and Saturday nights through their powerful telescopes. The Peninsula Astronomical Society hosts viewing at the Foothill College Observatory in Los Altos Friday nights. And the Lawrence Hall of Science has viewing on Saturdays. Finally, my own club, the San Francisco Amateur Astronomers, hosts a monthly Star Party at Mt. Tam in Marin, along with a lecture at the Mountain Theater. I often give tours of the night sky at the Mt. Tam star parties.

There's no excuse if you live in the Bay Area. And if you are not in the San Francisco Bay Area, check the Night Sky Network to find a club and activities near you.

The Very Long-lasting Total Lunar Eclipse of 2011

On Wednesday June 15th, viewers in the eastern hemisphere will be treated to a very long-lasting Total Lunar Eclipse, a 100-minute marathon of an eclipse that will reveal the center of the Milky Way in the backdrop as the bright Moon is enveloped in the darkest part of Earth's shadow. Unfortunately for those of us on the other side of the Earth, including here in San Francisco, we will miss the entire eclipse. (But we will get a nice lunar eclipse later this year, on December 10th.)

As for June 15th, this particular Total Lunar Eclipse will be longer than most for two reasons, (a) the Moon passes nearly through the center of the Earth's shadow, and (b) the Moon is nearly at Apogee, when it is farthest from the Earth (and hence appears a bit smaller than usual and takes longer to pass through the Earth's shadow). For my colleagues in Germany, the Moon will rise already in mid-Eclipse, which is an outstanding sight that I have seen one time in the past. Moonrise will be at approximately 9:30 pm, and the Moon remains in total eclipse until approximately 11:00 pm. That would be something to enjoy from a spot with a good eastern horizon. For other locations around the world, use this chart from the NASA Eclipse Web Site to determine the timing for your location. I wish my friends on the other side of the world clear skies and happy viewing!

KFOG Podcast - June 10, 2011

KFOG's Irish Greg and I talk about Saturn and a Double Star, the Big Dipper and asterisms, a fun event where I'll be showing off the night sky, observatories that have public viewing nights, and a massive solar flare. Listen here. A good time is guaranteed!

Double Star and Planetary Close Encounter: Porrima and Saturn

Light-polluted skies allow us city dwellers to only see the brighter objects in the night sky. Luckily, there are plenty of bright objects to see, and for the next few weeks Saturn has a close-encounter with a fairly bright double star. It's time to get out your telescope and put it to work, for the reward will be worth it.

The double star, Porrima, is a double star system located about 40 light-years away, relatively close to the Sun in the grand scheme of things. The two stars orbit each other about every 170 years, and as they do so, the apparent distance that separates them changes (from our Earth-bound point of view). Right now, the two are well separated, meaning that with a telescope pointed at Saturn you will see the two stars as distinct objects. Only a few years ago, their alignment was such that you would have needed a very powerful telescope to see the two stars in the Porrima system as individual stars. Right now, if you put Saturn into view in a small to medium telescope, you will also get the Porrima system in your field of view as well.

The diagram (above) illustrates where to find Saturn and Porrima over the next few days, and this article from Space.com also provides insight and additional diagrams to help you see this sight.

So seize the moment and be an amateur astronomer for a night, making a fun discovery for yourself.

Twin Stars and Moon in the West

As the days lengthen and the sky stays lit well into the evening, many familiar constellations are rapidly slipping out of view. The bright twin stars of Gemini, Castor and Pollux, are fading fast and will soon be gone from the night sky. Enjoy a few days of this sight, with the addition of a fine young Moon in the sunset sky this weekend.

Eclipse Season: Three Solar and Lunar Eclipses all in a row

For most people it is a surprise to learn that Solar and Lunar eclipses are quite frequent events. Every six months we have an "Eclipse Season" in which we have two or sometimes three eclipses over the course of a few weeks, depending on the exact geometry of the Sun-Earth-Moon trio. June is one of these months, starting with a Partial Solar Eclipse (today), then a Total Lunar Eclipse mid-month, and finishing with a Partial Solar Eclipse (actually in July, but just hours after the end of June!).

Eclipses are indeed common for Planet Earth, but for a given fixed location on the planet, eclipses are less common. For example, the first eclipse (Solar) of June is visible only from the very far north regions of the planet. The Total Lunar Eclipse mid-June will be visible primarily in the eastern hemisphere, so for those of us in San Francisco, it will take place during the day when we cannot see the Moon. And the final (Solar) eclipse of this eclipse season will be visible only in a small region of the globe deep in the southern hemisphere.

Eclipses come in "seasons" because they can only happen when the Moon is precisely positioned to cast its shadow on the Earth, or when the Moon passes precisely through the Earth's shadow. As the Moon's orbit is not exactly aligned with the Earth's orbit, the two orbits (and shadows) come into alignment for a few weeks every six months. The rest of the time, the shadows of the Moon and Earth miss each other and we are eclipse-free!

Since eclipses are such dramatic events, when they are visible in your area, you should go out of your way to see them. For us in California, the next good eclipse will be a Total Lunar Eclipse on December 10th. More on that when the date draws nearer.

Meanwhile, if you want to know more about upcoming eclipses, visit the excellent on-line resource from NASA. The NASA Eclipse Web Site is filled with detailed information about solar and lunar eclipses, including maps, charts, and exact timing for each event. Another excellent resource is the EarthView Eclipse Network. The image (above) is courtesy of the EarthView Eclipse Network.

Planetary Lineup on May 21st

With all of the talk about May 21st, I felt it would be helpful to guide observers to a genuine, heavenly lineup that will create a beautiful pattern in the morning sky on the 21st and 22nd. During the entire month of May, the four nearest planets to Earth have been creating a beautiful sight in the morning sky just ahead of sunrise. On May 21st and 22nd, Mars, Mercury and Venus form a compact cluster. Bright Venus is the "guide star" to help you find this grouping in the east. You will want to look about 30-45 minutes before sunrise, and you will need binoculars to see Mercury and Mars, but Venus will shine brightly despite the glare of the soon-to-be-rising Sun. Jupiter is also quite visible in the sky, but each day pulls away to the upper right (toward the south-east) a bit more from the other three planets. Note that the image of the view toward the east, which comes courtesy of Sky & Telescope Magazine, demonstrates that astronomers are confident we'll have something to see the morning of the 22nd!

Venus, Jupiter, Mars and Mercury in Conjunction

Four of the five most-visible planets are bunched together in the morning sky, creating beautiful patterns along the eastern horizon at dawn for the next few weeks. Each day the four planets change slightly in position, with bright Venus guiding your eyes to the right spot on the horizon where you can see these four points of light. Use binoculars to find all four planets - Mercury and Mars are much fainter than Jupiter and Venus - and use this amazing animation on the Sky & Telescope website to find the exact pattern as it changes each day. In San Francisco, you will want to look for this between 5:00 and 5:30 am, before the glare of the sunrise washes out the view of the planets.

KFOG Podcast - May 6, 2011

In today's podcast, KFOG's Irish Greg and I talk about the big planetary conjunction, how to find deep-space objects, upcoming astronomy lectures and star parties on Mt. Tam, and the likelihood of astronomical chaos on May 21st :-) Listen here!

Eta Aquarid Meteor Shower 2011

Meteors are wonderful to see, arriving unannounced and fleeting in an instant across the sky, obligating the hopeful viewer to pay attention or miss this spectacle of the heavens. On any given night if you simply are out viewing the skies, you will probably see one or two, but throughout the year there are special times when the Earth's orbit takes us through a region of space dust, creating meteor showers, in which the intensity and regularity of meteors increases dramatically.

The Eta Aquarid meteor shower peaks Thursday night, the night of May 5th into the morning of May 6th. This is not the biggest meteor shower of the year, but it certainly is interesting because it is caused by small bits of debris from the trail of Halley's Comet, the famous comet that orbits the Sun and is visible from Earth every 76 years. Comets leave small trails of debris in their wake, and comets that have orbits that intersect the orbit of Earth around the Sun create our annual meteor showers. So if you see an Eta Aquarid meteor tonight, you'll know it was once part of Halley's Comet, having been stripped away by the heating of the Sun on some past fly-by of Earth.

To see this shower, as is the case for all meteor showers, you need a dark location (even a backyard shielded from streetlights in the city will do), warm blankets, a recliner chair or a patch of grass to lie on, a big view of the sky, and patience. The name of this shower is based on Aquarius (the constellation) where the meteors appear to originate from, but they are visible all over the sky. Best viewing for this shower is early morning. The dawn sky will start to brighten around 5:00 am, so you will need to start early Friday morning if you want to see these. Have fun!

The Last Vestiges of the Winter Sky

The young Moon graces the last vestiges of the winter sky this week, creating a beautiful pattern in the west for several evenings in a row. The big, bold constellations of winter including Orion, Taurus and Canis Major, and the very distinctive asterism the Winter Triangle are sinking lower each evening into the glow of the sunset sky, and on May 4th, 5th and 6th the Moon enters the picture to create a spectacular evening picture.

I have been doing Star Parties and outdoor presentations on astronomy the last few weeks, and the change from week to week has been dramatic. There is a natural change to the sky each evening, as the constellations and bright stars along the celestial equator and zodiac (ecliptic) move approximately 1 degree westward toward the sunset. At the same time, the length of each day is growing, meaning that these great winter constellations are disappearing rapidly into the glare of sunset. But there is nothing to worry about -- they will make their way around the sky to rejoin the view in the early morning, and continue the great ritual of the sky changing slowly from one season to the next.

Viewing Gemini and a Deep Space Gem, M35

Spring skies are dominated by an array of bright stars and distinctive constellations. In April and May, the zodiac constellation Gemini dominates the view to the west, gracing the sky with the twin stars Castor and Pollux, and guiding the curious observer toward a gem in the river of the Milky Way, which flows across the legs of the twin brothers.

The star pattern of Gemini is of the brothers Castor and Pollux standing side by side. The bright twin stars represent the heads of the twins, and the stars that are below Castor and Pollux trace out their bodies, arms, legs and even a foot. An advantage to viewing Gemini in the Spring is that the brothers are standing upright and are easy to see, whereas in other times of the year when Gemini is visible, the brothers are not in an easy-to-spot orientation, or are directly overhead, a difficult thing to see.

If you have binoculars, you can try to spot a very faint but beautiful star cluster called M35 near the foot of Castor, the twin on the right-hand side of the pair. You will need a star chart (click on the image above, or try this fine star chart) to locate this small circle of stars but if you have patience and a dark viewing location, you will know you have found it because M35 seems to glow in the view of your binoculars compared to the stars around it. The stars in M35 are quite distant, nearly 3000 light-years away (but still within the Milky Way galaxy).

Happy viewing, and good luck with M35!

Five Weeks of Planets in Conjunction

We are entering a period of time in which several planets are going to be in close proximity to each other, creating special alignments called "conjunctions." Mars, Mercury, Jupiter and Venus are all occupying the same region of the sky from our Earth-bound point of view, and as these planets and our own planet are all in motion around the Sun, the pattern we see in the sky changes quite a bit from one night to the next. At this time, all of these planets are emerging from the glare of the brightening dawn sky, appearing in the east just minutes before sunrise. Therefore, the initial conjunction on April 19th is best visible with the aid of binoculars. But this is just the start of a five week period in which these planets move very close to one another, creating a beautiful series of patterns for the early morning observer.

Our planet moves nearly 2 million miles per day in its orbit around the Sun. The planets are also moving at high speed around the Sun in their respective orbits. Mercury and Venus move the fastest relative to Earth, and because of their unique position inside the orbit of Earth, we see their changing locations in the early morning just before sunrise, or in the evening just after sunset. The other planets, including Mars and Jupiter for the next few weeks, move more slowly from our point of view and move more steadily from east to west from one morning to the next. I'll be posting a regular series of updates over the next month as the various conjunctions come and go. The important thing for the observer is to find a good eastern horizon, dust off the binoculars, and be ready to get up just before sunrise to see these cosmic alignments.

The Moon and two Star Clusters: Pleiades and Hyades

The Moon graces the last vestiges of the winter sky this week, as the waxing Moon splits two of the prettiest star clusters, the Pleiades and the Hyades. This will be an exciting sight for stargazers, one that will look particularly magical through binoculars. So mark your calendar for Thursday April 7th and watch the show unfold all week long.

When the Moon emerges from the New phase and starts its 29 1/2 day journey around the Earth, the first few days are always a treat, because the waxing crescent offers so much to see through a telescope or binoculars, and even without optical aid, the sight of the thinly-lit Moon and the glow of Earthshine always catch your eye.

On Thursday, the Moon moves past the Pleiades star cluster, one of the best known clusters in the sky because the stars in it are fairly bright and concentrated into a small space, creating a kind of glow in the sky. Around the bright star Aldeberan in Taurus is the open cluster called the Hyades. These stars are also a close grouping in the sky, but not as tightly arranged, so you don't get the same kind of glow. However, through binoculars this cluster offers much to see.

Use the graphic (above) to help you orient yourself this week. You will want an observing location with a clear western horizon, away from streetlights or other distractions, and good weather. If you get all these conditions just right, you have no excuse for missing this gem of a celestial lineup. And if you live in San Francisco, come join me at the Cal Academy for a personal tour :-)

KFOG Podcast - April 4, 2011

In today's podcast with Irish Greg of the KFOG Morning Show, we discuss the upcoming alignments of the Moon with star clusters in the evening sky, and I tell Greg about the upcoming festivities on Thursday in San Francisco at the Cal Academy's "NightLife" party celebrating Yuri's Night. It's quick and fun, so click here to listen.

Get Involved: Globe At Night, Lectures, California Academy of Sciences

There is always something to do if you are interested in getting a bit more involved in astronomy. Right now, you can learn at a lecture, attend a star party, or take part in a global project to record light pollution while learning about new constellations. Read on for details.

Here in San Francisco, the California Academy of Sciences hosts a lecture series on astronomy topics. The Dean Lecture Series features talks on some of the most riveting subjects in astronomy, and Monday April 4th is the next talk, presented by Joel Primack and Nancy Ellen Abrams, focuses on the most modern research in cosmology, that of Dark Matter and Dark Energy.

The California Academy of Sciences also has a fun event every Thursday night with its "NightLife" series, transforming the museum into a fun party. Each week has a theme, and next Thursday April 7th is Yuri's Night, an annual celebration of the first man in space. If the skies are clear, you can find me on the Living Roof giving star tours alongside the docents of the museum showing off planets, nebulae and the Moon through telescopes.

If you don't live in San Francisco, visit the Night Sky Network website to find lectures and astronomy clubs in your area.

The Globe At Night project is now in the second phase, inviting Citizen Scientists around the world to support the effort to raise awareness of light pollution, learn about the night sky in your neighborhood, and pay attention to details of the constellation Leo the Lion. Take part - it only requires a few minutes and is an eye-opening experience.

Vernal Equinox, Super Full Moon, and other astronomical musings

I enjoy sharing highlights of the sky with friends and have been blogging for several years now, pointing out events of astronomical interest here as The Urban Astronomer. I was surprised to see the excitement and questions about the Super Full Moon, the coincidence of nature that is leading to a full moon at perigee today. The fact that the general public is being scared into thinking something bad is about to happen is unfortunate, but the fact that people will be out tonight looking at the full moon is the good outcome that I wish for. Of course, there is absolutely nothing to be worried about. Every 29 days the Moon swings a bit closer to the Earth than other times of the month, and that pattern of perigee and apogee, full and new, repeats in a beautiful "super pattern" every 18 years, something now known (but likely not fully understood) by the many who are reading about the Super Full Moon being the biggest one in 18 years.

There are numerous patterns and cycles in the heavens. Tomorrow, March 20th, is the Vernal Equinox, the semi-annual moment when the length of the day is exactly 12 hours everyone on Earth. I like that dynamic, a twice-a-year event in which we are all given equal periods of sun above the horizon and below the horizon, regardless of your latitude, regardless of whether you are in the Northern or Southern Hemisphere. That is a moment of beauty in the grand annual rhythms of our home planet.

The pattern of lunar repetition that lasts for just longer than 18 years is also responsible for the cycle of lunar and solar eclipses that take place around the world. I witnessed a total solar eclipse in Europe in July 1999, and the celestial dynamics of that eclipse will exactly repeat in August 2017 when a wonderful total solar eclipse will sweep across the United States. For me, it will be a rare chance to be standing in the shadow of the Moon on the second passing of this particular alignment of Moon, Earth and Sun, one that will be far more dramatic and meaningful to me than any particular Super Full Moon you might encounter between now and then. But in the end, if you can find some meaning and solace looking up at the Moon tonight, savor the moment and mark your calendar for April 2029 when the conditions will align themselves and present you with a chance to relive this magic moment when you saw a particularly big and impressive full moon. That is something worth pondering, and the rest of the media hype you are hearing right now should be simply ignored.

Image courtesy NASA.

Jupiter and Mercury: Prograde and Retrograde Motion

Elusive Mercury makes an appearance for the coming weeks in the evening sky, slowly progressing toward Jupiter as the two planets share the same space (from our point of view) just above the setting Sun. Although Jupiter is considerably farther away from Earth as Mercury, Jupiter's massive size more than makes up for that distance and makes it appear to us as a much brighter light on the horizon.

As Mercury rapidly arrives in the evening sky, it changes its location each evening quite a bit, and before long will be aligned with Jupiter, setting around the same time as Jupiter toward the end of March. As it reaches this point, it will then change its daily direction across the evening sky and move rapidly westward toward the Sun, something called "retrograde" motion. For a few weeks, people will say that "Mercury is in Retrograde" which is, from an astronomical point of view, very normal behavior for Mercury every few months. However, for many who follow astrology, this can be a very troubling time. Perhaps seeing Mercury with your own eyes changing location and moving gracefully across the sky, first in prograde motion (the basic motion of planets across the backdrop of stars, eastward), then in retrograde, will make its impact a little more friendly. Try it out for yourself and see.