Christmas Conjunction

Christmas Conjunction

This year for Christmas day, we get a nearly full Moon and a terrific alignment with the giant planet Jupiter and the bright star Aldeberan. They will dominate the night sky from sunset to sunrise, bringing a slowly changing pattern to bear as they soar high across the Christmas nighttime sky. The Moon’s gradual eastward motion will be perceptible in this tightly-packed alignment, rewarding the careful observer with a chance to see the Moon’s proper motion as it orbits the Earth, moving roughly its own diameter in distance across the night sky every hour, compared to Jupiter and Aldeberan. If you use binoculars to view the spectacle, you'll get the added bonus of seeing the Hyades star cluster, an open cluster of stars surrounding the star Aldeberan.

I wish you clear skies and nice viewing as we close 2012.

KFOG Broadcast - Dec 21, 2012

Today I joined Tim and Greg on KFOG In The Mornings to talk about the 2012 Apocalypse and 2012 Hoax, but we moved to more topics including the solstice, asteroids, comets, planets and stars, with calls from listeners too. We had a lively discussion and I am looking forward to more broadcasts with them in 2013. Click here for Part 1 of today's broadcast, and Part 2 of the broadcast.

Debunking the 2012 Hoax

We are in full swing this week with discussions and rumors about apocalypse on Friday December 21st, 2012. There are numerous claims, including impact by a rogue planet (Niburu), flipping of the Earth's axes, alignment of the planets, alignment of the Earth and Sun and the Galactic Center, and of course most famously, the end of the Long Count Mayan Calendar. All of these are either false or have no connection to science, of course, and scientists are therefore not worried about any of these, since there is absolutely no scientific evidence that any of these things will happen (or in the case of the end of the Mayan Calendar, that there is any reality-based significance of that numerological moment). All we will have on December 21st is the usual winter solstice, a geometric alignment that signifies the endpoint of an annual journey around the Sun, same as any other year.

Debunking the 2012 Hoax

I like to envision myself in a spaceship watching the Earth in its orbit around the Sun, viewing our home planet whisking across the heavens, spinning on its axis and enjoying its perfect location in the Solar System. From up there, you see the planet in its majesty, much as the Apollo astronauts did, a jewel floating through the blackness of space. And then I envision little people way down there on the planet, asking themselves if a rogue planet is in our midst, but is somehow unseen by anyone. And people worrying about a calendar that was invented years ago, the significance of which is completely irrelevant on the cosmic scale of the Solar System and Universe. And I don't understand how rational, thinking beings on Earth can become so self-obsessed and worried about all of these myths. But over the millennia there have always been doomsday rumors, and apparently it's in our nature to believe such stories. It's myth, and if you stand back and take in the big picture like the astronauts did, you cannot help but see just how irrelevant all of the speculation and rumors are.

If you want to read, on a point-by-point basis, just how science refutes each claim of the 2012 doomsday, visit the highly informative 2012 Hoax website. I have met the creator and contributors to this site, as well as David Morrison of NASA who has been speaking out against the rumors for several years. Read the real story and don't worry. I'll see you on December 22nd.

Image courtesy of 2012hoax.org.

KFOG Broadcast - Dec 13, 2012

Today I was a guest on KFOG In The Morning, with DJs Tim Jeffreys and Greg Gory. We had a spirited discussion about the Moon and Sun and how they conspire to create King Tides, and discussed the Geminid meteor shower. Click here to listen to the broadcast.

Geminid Meteor Shower 2012

One of the best meteor showers of the year, the Geminids, peaks the night of Thursday December 13th and continues through the early morning hours of Friday December 14th, as seen from the western hemisphere. This annual shower is generally a good show, and this year will be fully uninterrupted by moonlight, as the Moon is new and will leave the skies dark.

Geminid Meteors

Annual meteor showers are created as Earth passes in the wake of another celestial body, normally an asteroid or comet with a fine trail of dust and debris that burn up in Earth's atmosphere. In the case of the Geminids, they are caused by the remnants of an asteriod. This year, a new comet has left an additional amount of dust and debris and might cause the meteor viewing to be extra-intense.

To see the Geminids, find a dark location away from bright lights or direct lights, dress very warmly, and give yourself 5-10 minutes to adapt to the darkness. Look up and you'll see the meteors, as they will streak across any part of the sky. The common aspect of these meteors is if you trace the path of the meteor backwards, they will appear to emerge from the constellation Gemini (see image). But don't worry, you don't need to point any one direction or use a telescope. Meteor showers should be relaxing events, with plenty of time to gaze into the heavens and enjoy the glorious night sky.

Image courtesy of Sky & Telescope.

Asteroid Sighting

Ceres and Vesta

Finding the major planets in the night sky is easy, since the biggest and nearest planets outshine most stars. But the more distant planets and the asteroids pose a challenge, as you need to use a star chart or other guide to locate these wanderers, and you'll need binoculars or a telescope to see them.

Right now, two of the biggest asteroids are fairly easy to spot, being located high in the night sky and nearby a variety of easy-to-locate landmarks. There are good articles with additional details on the web, including Sky & Telescope and MSNBC Space. The MSNBC article has some very simple diagrams showing the exact location of the asteroids Ceres and Vesta, as they wander through the constellation Taurus. Using binoculars, they should stand out as fairly bright points of light and be distinct against the backdrop of stars in Taurus. I am not an 'asteroid hunter' and don't have lots of experience finding these, but I have used binoculars and telescopes to find the faint outer planets Uranus and Neptune, and anticipate that Ceres and Vesta will be similar. I'll report findings here on the blog comments.

The NASA spacecraft Dawn is on a mission to visit both asteroids, having already orbited Vesta and now is en route to Ceres. (Note: although Ceres was historically classified as an asteroid, it has recently been reclassified to a Dwarf Planet, just like Pluto!)

Image courtesy of Sky & Telescope.

Jupiter at Opposition: Closest approach of the Year

Jupiter at Opposition

Every 13 months the planet Jupiter and Earth align with the Sun, a special moment called Opposition. That represents the closest approach between the two planets, and means that Jupiter is at its brightest and 'fullest' for the year. It's unmistakeable when it rises, the brightest light in the east after sunset, blazing in its glory in one of the most spectacular parts of the night sky, near the constellations Orion, Taurus and Auriga and a large number of bright, colorful stars.

It's easy to spot the four brightest Moons (also known as the Galilean Moons) of Jupiter if you use a simple telescope or binoculars. With Jupiter at opposition, now is the time to take a closer look. If you want to actually identify which Jovian moon is which, use this handy app from Sky & Telescope.

Image courtesy Space.com.

Full Moon, Partial Eclipse, and Jupiter

Full Moon

This week we are presented with a collection of celestial alignments that are quite visible in an urban setting. The Moon reaches full phase on Tuesday, and will pass through the busy area of the night sky near the constellation Orion, the beautiful star cluster known as the Pleiades, and the bright planet Jupiter (on Wednesday). As it does, take a closer look with a pair of binoculars or simple telescope, since these objects will be easy to locate and are engaging to view up close.

The morning of Wednesday November 28th, the Moon touches the edge of Earth's shadow in space, creating a faint darkening of the northern limb of the Moon, also known as a Partial Eclipse. For San Francisco and the western US, the Moon's darkening will be most visible just before sunrise, during the 6:00 am hour.

Image courtesy of Sky & Telescope.

Leonid Meteor Shower 2012

Leonids

The Leonid Meteor Shower peaks this weekend, November 16-17, giving viewers a chance to enjoy the dazzling sight of bits of light streaking across the night sky. The Leonids occur each November as the Earth passes through the remnants of Comet Tempel-Tuttle, a minor comet that has left a stream of particles in its wake. As Earth glides through the meteor stream each November, we experience the beauty of the cosmic collisions that intensify and glow in our night sky.

To see the Leonids, find a dark location and let your eyes adapt for at least 10-15 minutes. Dress warmly and relax on a blanket or lawn chair, looking overhead or somewhat toward the east. The 'raidant' of the meteor shower is in the constellation Leo which rises high in the east after midnight, and the meteors will appear to emanate from that spot, but will shoot all over the entire sky, so most important is to have a view of as much of the sky as possible. City dwellers should find the darkest possible spot. In my own backyard, I place myself in a dark area where the local streetlights are shielded from view, allowing my eyes to adapt and see fainter meteors.

Stay warm, and enjoy the show. Here are some additional resources:

Space.com article about the Leonids.
Earthsky.org article about the Leonids.

Image courtesy howstuffworks.com.

Jupiter Returns to the Evening Sky

Jupiter rises into view.

The Moon heralds the return of mighty Jupiter to our evening skies. As October nears its end, the giant planet Jupiter is arriving in the evening sky earlier and earlier each evening, now shining brightly soon after 9:00 pm. Jupiter is dazzling in its new perch for the coming months high above the constellation Orion near the bright star Aldeberan. Jupiter will be approaching its brightest of the year in the coming weeks, as we move into an alignment of Jupiter at opposition in early December. Watch the nearly Full Moon glide past Jupiter early next week. And with the late sunrises that we experience this time of year, Jupiter is visible nearly overhead in the early morning hours before sunrise.

Image courtesy of Sky & Telescope.

Red Stars at Night

Evening Sky this week

This week, the dusk sky features alignments of planets, stars and the Moon that will accentuate the western horizon with two red ‘stars’ glowing in the colorful haze of twilight. The two ‘stars’ are a planet and a star, but both are quite distinctive because of their orange-red tinge. Mars is passing near the red supergiant star Antares, and the Moon will be sweeping past the two on the evenings of the 17th and 18th.

If you have an extra-clear western horizon, you can try to locate the faint Mercury and the very young Moon shortly after sunset on Tuesday 16th. This will require the use of binoculars to spot them, but if conditions permit, it will be quite impressive to see.

Image courtesy of Sky & Telescope Magazine.

The Morning Star and a Real Star

Venus and Regulus align

As the days grow shorter in Autumn and the Sun rises later and later, the early riser is rewarded with a clear view of the Morning Star in the east. Of course, it's not a star, but the very bright planet Venus. Each passing day, Venus moves gradually in comparison to the backdrop of stars and this week Venus aligns itself with the bright star Regulus in the constellation Leo the Lion. The two should make a fine pair, in particular on the morning of October 3rd when the pair will be a tiny distance apart, less than half the width of the Moon. If you are up before 6:30 am, face east and you'll have a fine view of this alignment.

Image courtesy of Sky & Telescope Magazine.

Comets and Galaxies

One of my primary resources for astronomy information is Sky & Telescope Magazine, and the companion website skyandtelescope.com. I have been a loyal subscriber and follower of this publication for decades, and find the news and information relevant and timely for the amateur astronomer. Two articles recently caught my attention, and I'd like to share them here.

Comets:

Comet Hale Bopp

Astronomers have discovered a comet that in 2013 may become a very major event. Comet C/2012 S1 was discovered last week, and when it comes in close to the Sun in late 2013, could rival Hale-Bopp as a major comet in the night sky. Let's stay tuned for updates on this one. Comets are wonderful and rare, and a bright one like Hale-Bopp was unbelievable, visible from big cities and spectacular from dark locations. I have memories of driving on highway 101 in the San Francisco Bay Area in 1997, looking at a comet through the windshield of my car.

Galaxies:

Hubble eXtreme Deep Field

The Hubble eXtreme Deep Field Observing Team has published a new image revealing 5,500 galaxies, the most distant as old as 13.2 billion years, meaning that it "emitted its photons only 450 million years after the Big Bang." Images like this are not just beautiful, but profound in their richness of information, revealing how far and wide our universe really is, and just how much more there is to discover.

Images courtesy NASA.

Viewing the Night Sky in City Settings

I am often asked "can you really see any stars in the big city?" Living in San Francisco, this is a reasonable question, since we have a great deal of light pollution in our region, and the sky is often glowing, seemingly obliterating all but the brightest of celestial objects.

Night Sky in an Urban Setting

My answer is always "of course you can see stars and constellations in the City," but it takes some discipline to make the most of urban star gazing. Here are a few factors to consider. First and easiest, you need to give yourself some time for your eyes to adapt to the darkness outside, since most urban dwellers live in well-lit environments, and need to allow enough time for their eyes to adapt before they can see anything. Spending 10 minutes in darkness should be plenty to get things going.

Second and somewhat more challenging, you can see a lot more in a city setting if you view the sky from a dark spot. I don't mean that you have to drive out of town to see stars, but rather you simply need to find a dark spot, the darkest one you can find where you live or a short walk from where you live. For example, in my backyard in San Francisco, there are spots where I can sit or lie to see stars where the light of nearby streetlights illuminates the space, and other spots where I am in the 'shade' of the streetlights. That will make a big difference, since my eyes will respond better to the faint stars above me if I am in the darkest possible spot in my backyard.

Third, you need the local weather conditions to help you out. Lower humidity is good for stargazing, since moisture in the air picks up and reflects light from urban areas, making the sky 'glow' which diminishes the view through the atmosphere out to the heavens above. Similar to humidity, there are other factors that make the night sky more or less transparent. I recommend to use the Clear Sky Chart as a guide to direct you when the skies are going to be optimal for stargazing, whether you do so from the City or the suburbs or the country. There is also an iPhone app for the Clear Sky Chart.

Finally, some kind of optics helps, even in bright city settings. A simple pair of binoculars or a telescope will reveal much more of the sky, even when there is light pollution. Very faint objects will be invisible, but many objects that are not visible to the naked eye will still be present with magnification and good quality optics.

Most important are cloud-free skies, and the patience and commitment to enjoy the night sky.

Morning Glory

Morning Glory

As the seasonal change of the approaching Autumnal Equinox starts to manifest, the morning sky is still visible when I get up, and the view to the east and overhead is spectacular. The stars of the big, bold winter constellations punctuate the view, with the Pleiades, Orion and Taurus dominating the scene, along with the bright planet Jupiter (and shimmering Venus lower on eastern the horizon). This week, the waning Moon lends to an already-exciting sky, so if you are an early riser, savor a few moments before you start your day, and enjoy the panorama that rises just ahead of the Sun.

Image courtesy of Sky & Telescope.

The Galactic Center: Staring Into the Heart of the Milky Way

Summer is prime time to look into the heavens and touch the wonder of the Galactic Center, the heart of our own Milky Way galaxy. Two bright constellations guide you to the center of the Milky Way, Scorpius and Sagittarius, which are easy to spot due south each evening shortly after sunset.

The Galactic Center

Our own Sun and Solar System occupy their special place 30,000 light years from the center of the Milky Way, and as we look out and around us into space, we view our own galaxy from within, along the spiral arms and toward the center. Many have seen the lovely band of the Milky Way when camping or far away from city lights, but the faint river of light is all but invisible in any urban area. Nonetheless, with binoculars, you can see deeper into the sky and discover some of the deep space wonders and faint objects that are visible between our own location and the center of the galaxy, an area full of star clusters and nebulae. So I encourage everyone to get a pair of binoculars, face south, and using the star chart (above) as a guide, aim between Scorpius and Sagittarius and meander from there upwards. You will encounter the Lagoon Nebula and the nearby Trifid Nebula, easily visible in city lights if you use a telescope or binoculars, and many more Messier Objects, the fuzzy blobs that dot the sky near the Galactic Center.

In six months, when the Earth has traveled half-way around the Sun, we'll be able to look in the opposite direction, toward the Galactic Anticenter, as I have described in a previous blog post. That is interesting to consider, but more exciting is the Summer when we can enjoy our own galaxy's finest wonders on full display.

Here's a link to an image of the Galactic Center on Sky & Telescope's website.

Image courtesy SkySafari.

Planet/Star Trio Fades into the Sunset

The "Trio" fading into the sunset

I've enjoyed watching the changing view of the evening sky over the past months, in particular as the pair of Saturn and Spica have become a trio with Mars. Saturn and Spica straddle the ecliptic and Mars has raced from its location far to the west of the pair in Spring, to a near-split of the two last week, and now as the trio fades into the sunset, Mars is continuing to glide eastward, this week being joined by a crescent Moon.

I've been pointing out this dynamic at star parties for the past few months, as it vividly illustrates the motion of planets in our Solar System, and it also highlights the differences in perceived speed of the outer planets, with Mars circling the Sun every 2 earth-years, and Saturn taking nearly 30 earth-years to accomplish the same.

Image courtesy Sky & Telescope.

Perseid Meteor Shower 2012

The big meteor shower of the year, the Perseids, peaks this weekend and promises a good show for all who can find dark skies and have the patience to enjoy them. The Moon will generally cooperate with viewers since it will only interfere very late into the night, and even then will only cast a small amount of glare on an otherwise exciting event.

The Perseids are a regular meteor shower that peak over one or two days each August as the Earth plunges into a stream of particles from the comet Swift-Tuttle. As we impact these particles at tens of thousands of miles per hour, we enjoy a spectacle of shooting stars darting across our night sky, sometimes one per minute, sometimes less or even sometimes more. Your ability to see more meteors depends upon three things: (a) dark sky, (b) dark adaptation, and (c) lateness of the night. The darker the sky, the fainter the meteors you will see. The longer you are in your dark environment, the better your eyes will adapt to the dark and enable you to see fainter objects. And finally, later in the night the Earth is intercepting more and more meteors, right up until the first light of dawn.

The shower peaks on Saturday night August 11th and Sunday night August 12th. Your best bet in the San Francisco Bay Area will be locations away from city lights with good views across the entire sky, but in particular with a good eastern horizon.

EarthSky has a helpful article about the Perseids. From EarthSky: "They radiate from a point in the constellation Perseus the Hero. You don’t need to know Perseus to watch the shower because the meteors appear in all parts of the sky. The Perseids are considered by many people to be the year’s best shower, and often peak at 50 or more meteors per hour in a dark sky."

Watching the Solar System in Action

As we move into August, we can witness the gradual change in the night sky from one evening to the next as planets near and far align and move among the backdrop of stars in the heavens. In particular, Mars is moving quickly in its path around the Sun, and as it does so in early August, it will move just between a pair of bright objects, the star Spica and the planet Saturn. The diagram illustrates the position at the end of July, and the spacing between Mars and the pair will close as we move into August. This is a superb opportunity to witness the motions in our Solar System as we on Earth move around the Sun (making the trio of planets and stars appear lower in the sky each night), and Mars moves eastward with respect to Saturn.

Image courtesy of Sky & Telescope.

Get Involved: Star Parties and Astronomy Lectures

Wherever you live, there are always good astronomy events happening in your town. The Night Sky Network is the first resource you should check for the latest events anywhere in the world.

Every weekend, the observatories and science museums in the San Francisco Bay Area open up for public viewing, such as the Chabot Space and Science Center and Foothill College Observatory.

Lecture: In the San Francisco area, I always encourage people to visit the monthly meetings of my astronomy club, the San Francisco Amateur Astronomers (SFAA). Every month we have some of the best astronomy speakers present their latest ideas, and this month is no exception, with a science history talk presented by John Dillon entitle "Galileo Reconsidered" on Wednesday July 18th. Click here for more details.

Lecture & Star Party: Once a month at the top of Mt. Tamalpais in Marin County, high above the thick fog of a San Francisco summer's night, you can find a wonderful Saturday night event featuring a lecture in the Mountain Theater, and stargazing with the SFAA afterwards. This Saturday, July 21st, features Dr. David J. Des Marais from the NASA-Ames Research Center. The tile of his talk is “Astrobiology Investigates Life in the Context of Space.” Click here for more details.

I hope you can join us for an upcoming event.

Beauty in the Dawn Skies

Dawn Sky: Moon and Planet

The next few days feature a fine lineup of Moon and Planets in the dawn sky. As the Earth swings around in its most distant stretch of its orbit (we were at aphelion last week), the constellation Taurus gradually becomes visible in the morning sky, with its bright star Aldebaran rising just ahead of the Sun. Looking in that direction of the sky, the giant planet Jupiter is present near the "V" of Taurus, as well as the planet Venus, fresh off of the Transit and now heading westward from our point of view against the backdrop of stars. These bright objects are visited by the crescent Moon for a few days this weekend, so take a moment and look east if you are up before the sunrise.

Image courtesy of Sky & Telescope.

Planets moving along the Ecliptic

Position of Mars in early July

Looking into the evening sky, two planets are visible in the south-west and are heading toward a 'conjunction' in August when they will line up with a bright star. Mars is the faster-moving of the two, changing position each night against the backdrop of stars as it travels around the Sun roughly every two Earth years. In a previous blog post, I noted the position of Mars in the constellation Leo, where it emerged from retrograde motion in April and has been moving steadily east each night since then. Last week I showed its position in another blog post highlighting how far it had traveled from Leo, now moving into Virgo. And in one month, during the middle of August, Mars will finally arrive between Saturn and its stellar neighbor Spica, creating a wonderful sight.

But these milestones are just the highlights that punctuate the journey. In fact, looking out each night at Mars is quite wonderful, seeing it shifting its position along the ecliptic, illuminating the pathway of the planets, Sun and Moon across the zodiac band in our night sky. I point this out to guests at the California Academy of Sciences when I give talks there during NightLife each Thursday, and this is one of the most inspiring things people discover as they look up in the sky with me -- that they can actually see the motion of Solar System objects by just looking up and paying attention to what they see.

If you want to learn more about Mars, and the upcoming landing of the Mars rover Curiosity, check out the Night Sky Network page called "We're Mad About Mars!"

Image courtesy of SkySafari.

Summer looking South-West

Now that the summer constellations have fully emerged, I am enjoying the sparkling views at night as I look from one horizon to the next. Last week I focused on the eastern horizon while conducting a Star Party at Mt. Tam, but the next night I was in my yard viewing the south-western sky, and was so amazed by the view.

South-West Sky in June

In early summer, Leo is diving down toward the western horizon, with the familiar lion shape almost face-down. Mars has been steadily moving eastward across the ecliptic, from its springtime position near Regulus in Leo, now more than half-way to Spica in Virgo and a lineup with Saturn in August.

Bright Spica and Regulus, with the planets Saturn and Mars between them, create a beautiful string of bright shiny objects low along the south-west, and from my backyard in San Francisco, the view to the south-west is fairly dark, so everything was just right in the sky as I gazed in that direction. To the left (east) Scorpius is coming up into view and later in the evening dominates the southern horizon -- but I'll have more on that in a future post. And directly above, you can enjoy the dazzling star Arcturus and the lovely Northern Crown just nearby (Corona Borealis - - read more here). Just below Virgo is the easy-to-spot constellation Corvus. The sky is full of wonder, and summer weather makes it more fun and relaxing to see the sky. Wherever travels take you this summer, dedicate an evening to star gazing and reward your senses with the beauty of the heavens.

Image courtesy of SkySafari.

Slender Moon

It’s been a full lunar cycle since the Annular Eclipse of the Sun in May, and now the Moon once again graces the evening sky with its slender disk, slicing below the ecliptic in a line just south (left) of the planet Mercury and the star Regulus. I enjoy spotting the very young Moon such as we will see on Thursday 21^st, not just in the glow of dusk alongside the emerging planets and stars, but also in the mid-day sky where it is high above, near the summer Sun. Finding the young disk of the Moon in the daytime sky takes patience and focus, but with a well-placed location next to a building or tree that solidly blocks out the bright Sun, the thin Moon is a treat to find. 

Image courtesy of Sky & Telescope.

Transit of Venus on June 5

It's showtime! 8 years ago, the planet Venus passed in front of the Sun, and now it's time for the second of the pair of transits before a 105-year break. The view from San Francisco and the west coast of the US will be very fine, with the event visible in the western sky starting around 3:00 pm until sunset.

I spoke with Ben Trefny of KALW radio about the Transit of Venus. You can listen to it here. 

Much is being written about this transit. It fits into the category of 'unique and rare astronomical events' that are special and worthwhile to see if only for the rarity of the event. Venus makes two transits of the Sun every 100+ years, and the last one of this pair (8 years ago) was not visible in San Francisco, so Tuesday June 5th is a special opportunity to see this event. The website transitofvenus.org is an outstanding resource, as is Sky & Telescope with their historical writeup of past transits. Safe viewing tips can be found here on EarthSky.

I am going to take part at an event co-sponsored by the San Francisco Amateur Astronomers and NASA Ames in Mountain View. And there are many more places to see the transit with amateur and professional astronomers around the San Francisco Bay Area - thanks to this list from the AANC. However, if you don't get out to an event, no need to worry. You won't need a telescope to see this, just eye protection as you would use during any solar viewing, and you will easily spot the disk of Venus moving slowly across the Sun's surface. Make the effort; the next chance will be in 2117.

Image courtesy of Wikipedia.

Partial Lunar Eclipse of June 2012

Early in the morning hours of Monday June 4, west coast viewers will witness a partial lunar eclipse. This follows the dramatic Ring of Fire Solar Eclipse by roughly two weeks, the interval from a New Moon (with the Moon causing the solar eclipse) to the Full Moon (with Earth causing the lunar eclipse). These are two events in an Eclipse Season, and as should be expected, if one event is really great (the annular solar eclipse) the next will be less impressive (just a partial lunar eclipse).

Nonetheless, it's always a treat to see an eclipse of the Moon, and this one will be a nice sight, starting at 3:00 am for viewers in the pacific time zone, peaking around 4:00 am, and ending around 5:00 am as the light of dawn starts to break. EarthSky has some good images.

Image courtesy Wikimedia Commons.

Corona Borealis - The Northern Crown

Facing east in May, you can see a number of very nice constellations filling the sky from horizon to zenith. The small constellation Corona Borealis takes some work to find in city skies, but it something to discover and remember among the bright stars and busy constellations of the springtime sky.

Corona Borealis, or The Northern Crown, is a simple "C" of stars sandwiched between the constellations Bootes and Hercules, two big constellations that dominate the late spring skies. Bootes is easy to find because it contains Arcturus, the third brightest star in the heavens, and is located just down the 'arc' of the handle of the Big Dipper. Hercules is a massive constellation that features the well-known deep space object M13, or the Great Globular Cluster. But Corona Borealis has none of these special features; it's just a simple collection of 2nd and 3rd magnitude stars that are grouped together nicely and are a simple pattern that is easy to locate, giving some texture to a small patch of the heavens for those whose eyes stop for a moment between the "big guys" in the sky. Try to spot it tonight.

The mythology of Corona Borealis is interesting, stemming from the crown of Ariadne, daughter of King Minos of Crete.

And the Northern Crown is balanced in the southern hemisphere by Corona Australis, the Southern Crown. I'll be on the lookout for that one this summer when Scorpius and Sagittarius come into view.

Image courtesy of Sky & Telescope.

Report from Mt. Shasta: Ring of Fire Annular Eclipse

I led a Road Trip to Mt. Shasta for viewing of last Sunday's Ring of Fire Annular Eclipse. The event was well attended and we had a nice array of telescopes and a lot of very enthusiastic participants taking in this special event, each in their own way.

I observed the January 1992 annular eclipse from San Diego, CA, and had a very different experience, finding the eclipse at that time to be interesting but not inspiring. However, Sunday at Mt. Shasta, the Ring of Fire was very inspiring. I enjoyed the view through a number of telescopes, including some Hydrogen-Alpha, and the usual white light filters. I enjoyed the collective shout of excitement as the eclipse reached annularity. And I was pleased to simply have clear skies, with some light high cloud but nothing that disrupted the view of the magical display in the sky.

I'll be posting photos and links of pictures and videos from the event. If you were at Mt. Shasta, send me a link and I'll add it here: 

My own video showing the scene at the Mt. Shasta Resort.

Video of the actual solar disk from Anju Saksena. Note the sounds of the crowd from 7:00 to 7:30.

More photos from Anju Saksena on her Facebook page.

The SFAA Facebook page.

View of the Moon's shadow on Earth from space.

Annular Eclipse image (above) taken at Mt. Shasta Resort, courtesy John Belew.

KALW Broadcast - May 16, 2012

Ben Trefny of KALW's Crosscurrents interviewed me about the Annular "Ring of Fire" Eclipse. It's a wide ranging discussion, with some fun mixed in as well. Listen here.

KFOG Broadcast - May 9, 2012

I always enjoy visiting the Morning Show at KFOG to talk astronomy. Listen in to our fun discussion about the Super Full Moon, the Ring of Fire Eclipse, and Lunar Gravity! Click here to listen.

Ring of Fire Eclipse 2012 in Northern California

It's May, and that means it is almost time for the Moon to cast its shadow on the Earth and create a wonderful spectacle in the afternoon sky. On Sunday May 20th, we will experience a very significant Solar Eclipse, a very rare and exciting "Ring of Fire," also known as an Annular Eclipse.

The afternoon of Sunday 20th, much of the western United States will see a very deep partial eclipse of the Sun. But in a special path across Northern California and several western states, we will witness the Moon fully enclosed within the disk of the Sun, creating a beautiful "Ring of Fire" effect. This effect will only last about 4 minutes, and will only be visible from the special path. Earth-Sky has an excellent overview article about the eclipse. If you choose to remain in San Francisco, you will see a very deep (90%) eclipse of the Sun, but if you travel a few hours north, you will experience the full Annular effect.

The map shows the path of the Moon's shadow across Northern California. I plan to watch this eclipse from the Mt. Shasta area, and there are many more areas to go to see this event. If you wish to join me and the San Francisco Amateur Astronomers (SFAA), check this article on the Ring of Fire Road Trip or my past blog post. But you have lots of choices, and depending upon the weather outlook, you will want to have some mobility to get to a good viewing spot in case of (gasp!) clouds. Here is a much more detailed map from Eclipse-Maps.com.

One of the most important factors when preparing to watch an eclipse is eye protection. I encourage all readers to purchase specialized viewing equipment such as eclipse glasses or a shade 14 welder's filter. At all times, the intense radiation from the Sun can cause permanent eye damage and even blindness, and during an eclipse it is tempting to stare up at the Sun. However, with simple planning and preparation, you can enjoy the eclipse without any fear of damaging your eyesight. Mr. Eclipse has some valuable information about eye safety and resources for buying solar glasses.

I wish all of you clear skies and a great view of this special event.

Map courtesy of Eclipse-Maps.com.

Planet and Star Pairs Line the Sky

This April, as the weather has improved and I've been conducting star parties, I've found myself focusing on some striking pairs of planets and stars that punctuate the night sky this spring. The pairs are all located in the Zodiac, the band across the sky that houses the well-known 12 signs, and also the planets and the Moon. The pairs of planets and stars are easy to find, and when you find them, you get a big picture of the band of the Zodiac, with the planets in our Solar System superimposed upon that band.

Shortly after sunset, it is quite easy to find Mars, shining a bright orange color almost directly overhead, and just next to it, the bright blue-white star Regulus in the constellation Leo. Starting from this point and looking North-West toward the point of sunset, you will encounter the twin stars Castor and Pollux, the two brightest stars in the constellation Gemini. And starting again at Mars, if you look toward the South-East, you will find the next pair along the Zodiac, the planet Saturn and the bright star Spica in the constellation Virgo.

If you trace a line from Saturn through Mars, and then toward the North-West through Gemini and to the brilliant planet Venus, you will be tracing out the path of the planets along the night sky, through the band of constellations we call the Zodiac, and along a line in space called the Ecliptic. It's a great way to get acquainted with the heart of our night sky, and this week you can watch the Moon gliding through the same space, as it makes its 29 1/2 day journey around our home planet.

Images courtesy of Sky & Telescope.

Lyrid Meteor Shower 2012

Meteor Showers occur throughout the year, and a bright Moon can wash out the view, so when we have ideal conditions for a shower, it's a good idea to take a few minutes and try to see it. Tonight, the Lyrid Meteor Shower reaches its peak, and we will have no moonlight to interfere.

The Lyrids are named after the tiny constellation Lyra, and although it is a small constellation it features the fifth-brightest star in the night sky, Vega. The constellation is the 'radiant' of the meteor shower, meaning that the meteors appear to emanate from this area of the night sky. Lyra rises before midnight and as it climbs higher in the sky during the late night into the early morning, more and more Lyrids will be visible.

As is the case with all meteor showers, you want to dress warmly, find a relaxing spot in a dark area (mountains, backyard, beach), be sure you have a wide view to the night sky, and have some patience. Observing is good with a friend or two, since you might see one meteor in a part of the sky where your friend is not looking, or vice versa.

I wish you dark skies and a pleasant night observing.

Image courtesy of Astronomy.com.

Get Involved: Mt. Tam Lectures, Globe at Night

Part of the joy of astronomy is to gaze up in the heavens and enjoy the spectacle of looking into the vastness of space. And for many, another part of the joy of astronomy is learning about space science. I like to highlight opportunities in the San Francisco Bay Area for both of these perspectives, and one of my favorite places to both learn about space and also enjoy gazing into the heavens is on Mt. Tamalpais in Marin County, where the public is invited to take part in monthly lectures by leading astronomers, and immediately afterwards, enjoy the heavens through telescopes provided by our local astronomy club, the San Francisco Amateur Astronomers (SFAA). The 2012 season of lectures kicks off this Saturday April 21st with Dr. Alex Filippenko of UC Berkeley, talking about the upcoming Ring of Fire Solar Eclipse in May, and the Transit of Venus in June. I'll be there giving a night sky tour following Dr. Filippenko's lecture, and the weather is cooperating so a good evening is in store. More information here.

The annual dark sky awareness event called Globe At Night comes to a close this week. The public around the world is invited to find one of three bright constellations and estimate how many of the stars in the constellation are visible from your location. By submitting your results online, you contribute to a world-wide database of sighting, helping to build a global map of light pollution and to raise awareness of this issue.

No matter where you are, you can find astronomy events on the Night Sky Network. Check out this great resource and Get Involved today!

Venus in Motion

The brilliant planet Venus shines each evening in the west, leaving most who see it saying "that's not a planet, that's an airplane, isn't it?" For the next two months, its orbit around the Sun is bringing it closer to Earth each day, en route for a rare and exciting Transit on June 5th (for Western Hemisphere viewers).

Because Venus is located nearer to the Sun than Earth, as it moves in its orbit around the Sun it only is visible in the evening sky after sunset, or in the morning sky before sunrise. Right now, as we observe Venus in the evening sky, we can watch it speed around the Solar System by comparing its position to the backdrop of stars in the distance. Last week, Venus passed near the Pleiades star cluster, and for the next few weeks it will glide away from the Pleiades, as the star cluster moves quickly into the glare of the sunset sky while Venus hangs high in the west. At the end of April, Venus is at its greatest brilliance (brightest) for the year. Nakedeyeplanets.com has excellent charts showing the changing position of Venus in the heavens.

Soon after greatest brilliance, Venus will reverse its course into retrograde motion and begin a slow fade into the glare of the sunset sky as it rapidly closes the gap for its nearest approach to Earth and the June 5th Transit. I'll have more on the Transit of Venus in another article. For now, enjoy the bright shiny object in the west as it holds 'center stage' for all of us.

Image courtesy of Sky & Telescope Magazine.

Vernal Equinox, Full Moon, Passover and Easter

As Spring arrives, so do the religious festivals of Passover and Easter. These two festivals change date each year, happening sometime in March or April. These festivals are tied to the phase of the Moon and the Vernal Equinox (the first day of Spring), and hence they change date each year. Tonight's Full Moon is the event that ushers in these festivals. How does the timing of these events work?

The Vernal Equinox is the first day of Spring, the day when the Earth's tilt is aligned to its orbit around the Sun, so the poles of the Earth tilt neither toward the Sun or away from the Sun. On this day (and again in the Fall at the Autumnal Equinox), every place on Earth experiences the same number of hours of Sun above the horizon and Sun below the horizon, hence 'equinox' for equal lengths of day and night.

The first Full Moon following the Vernal Equinox marks the start of the religious festivals in Judaism and Christianity, with Passover taking place on the day of the Full Moon (today), and Easter on the first Sunday following the Full Moon (this Sunday April 8th).

Tonight's Full Moon will be very close to the bright blue star Spica, the brightest star in Virgo, and just to the left of Spica you will have a nice view of the planet Saturn. Enjoy the view!

Image courtesy of Sky & Telescope Magazine.

Young Moon, Jupiter and Venus shine in the West

The next few evenings feature a beautiful alignment of the two bright planets Venus and Jupiter, and the young Moon as it starts its monthly journey around the Zodiac. Every 29 days, the Moon makes a 1.6 million mile journey around the Earth, and as it does, it travels across the entire Zodiac, the band of constellations through which the Sun and planets appear to "travel" around our nighttime sky. Each month following the New Moon phase, the young Moon slips quietly into the evening sky, first appearing near the horizon as a thin sliver of light, and each night growing in size and distance from the setting Sun. This month, with Jupiter and Venus in close proximity, the changing view from one night to the next promises to be beautiful. Now all we need in San Francisco is clear skies!

Image courtesy of Sky & Telescope.