Watching Planets Move: focus on Mars and Jupiter

Jupiter, Mars and Moon on 6 March

I love watching planets move. So did the ancient Greeks and they named these wandering objects 'planetes' and to this day, the name stuck. The planets normally move in a graceful arc across our night sky, slipping from one Zodiac constellation to the next, bringing a change in composition to the tapestry of the night sky, modifying the normal patterns of the constellations. And showing us just how extraordinary our Solar System really is, a collection of planets orbiting a star alongside us on Earth, and creating a window into the universe of how systems emerge around our galaxy and the universe. 

Right now, Mars and Jupiter are extremely well placed in the night sky. They both are occupying the 'Winter Hexagon' which is a rich span of winter sky that includes many of the brightest stars in the night sky. At the moment, Mars and Jupiter are nicely bookending the circle of stars in the hexagon, Mars on the east side of the circle and Jupiter on the west side. Both planets are moving gradually eastward and the pattern we see now will change over the coming weeks. In particular, Mars will form very interesting patterns with the twin starts of Gemini, something you can watch and enjoy from night to night. 

My latest podcast for the Volkssternwarte München in the Translunar series features this alignment and part of the night sky. Give it a listen on a night when you have clear skies and you will make discoveries on your own. 

Image courtesy of SkySafari. 

Share the Night Sky - Broadcast on KPOO

During the recent Bay Area Science Festival, I had the privilege of sharing the night sky with DJ Marilynn and the listeners of KPOO during a special broadcast on Thursday evening October 22nd. Our hour-long broadcast features many different topics: 

• How to find a good spot for stargazing in the city, and how to prepare for looking at the night sky. 
• How to find planets such as Jupiter, Saturn and Mars this fall and winter, along with the constellation Sagittarius. 
• How to find the Summer Triangle and connect it to the Milky Way. 
• How the view of the sky changes when viewing from different places around the world. 
• How to understand the motion of the constellations in the northern sky, featuring Cassiopeia and the North Star. 
• How to enjoy a view of Orion the Hunter later in the evening. 
• How to further your experience with the night sky. 

Click here to listen to the broadcast. 

Image courtesy of KPOO-FM.

The Spectacular Winter Circle

Winter brings out the best in the night sky. Some of the finest stars in our galaxy are concentrated in a region of the sky that shines with an intensity that you just can't miss on a clear night. A collection of extremely bright stars form a nice shape that is fun to look for, the Winter Circle. This asterism features 5 of the 8 brightest stars in the entire night sky, and in total 7 very bright stars that glow in the south on long winter nights.

The Winter Circle

Given that all of the stars in the Winter Circle are bright, this is a relatively easy target for city dwellers who might not normally pay attention to the night sky. The stars are part of six different constellations covering a fairly significant part of the winter sky. January evenings feature the Winter Circle moving gradually from east to west across the southern horizon. Given the span of this asterism from the lowest point at the star Sirius (see diagram) to the highest point at the star Capella, you will need a fairly clear view across the southern sky. For me, it's easy to spot one or two constellations wherever I am, but seeing all six constellations and all 7 of the bright stars in the circle requires that I have a good horizon and not much else blocking the way.

Most people can quickly and easily find the constellation Orion, and from there you can start your trip around the circle. Rigel is a blue supergiant star that is one of the kneecaps of the hunter Orion, and it is one of my favorite stars because of the intensity and color. Orion's 'belt' can help you find two other members of the circle, by following the belt up toward Aldeberan and down toward Sirius. The other stars are then easy to find looking up and left of Orion toward Gemini, Auriga and Procyon.

Finding a wide open space on a clear winter night where the grandeur of the Winter Circle is on full display is one of my favorite things. The stars are rich and intense, and the utter size of the circle make the viewing of this amazing pattern worth the effort. Dress warm and savor the moment. You will be glad you made the effort.

Image courtesy of SkySafari.

Update: good article from Sky & Telescope on the Winter Circle. They call it the Winter Hexagon.

Moon and Winter Stars and Star Clusters

Moon visits the Winter Circle

The March evening sky features the bold constellations and bright stars of Orion, Gemini, Taurus, Canis Major and Canis Minor. Jupiter is currently occupying a prominent position and this week the Moon passes through this rich part of the sky, enhancing the view with its close encounters with stars and star clusters. On March 7th the Moon will be passing through the Hyades star cluster and two days later through the band of the Milky Way between Orion and Gemini. If the weather permits, take in the view and watch the Moon make its grand procession through the Winter Circle. Binoculars will enhance the view.

Image courtesy of Sky & Telescope.

Bright Stars and Planets in the Morning

Fantastic Morning Sky

I get up early, and I am quite aware of the fact that as autumn begins, the mornings are darker and darker. Here in the west side of San Francisco, autumn is when our clear skies return (following the summer fog) and the sky starts to come alive. My early start of the day means that I get to see the fabulous winter skies and the brilliant planet Jupiter when I step outside to get the newspaper. The southeasterly view just before dawn is riveting, with Jupiter dominating
the sky to the east, and the stunning constellation Orion, and the brightest star in the sky Sirius, to the south.

Later this week, the waning gibbous Moon glides high across the sky, passing near Jupiter on the 28th. As the sunrise moves a few minutes later each morning, the sky becomes more accessible and if you can spare a minute of your morning routine, you'll like what you see.

Image courtesy of Sky & Telescope.

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.

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.

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.

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.

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.

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.

Take part in "The Globe At Night" project - just look up at the sky tonight!

For the next week everyone is invited to participate in a global effort to measure light pollution and to learn about stars and the sky in your neighborhood, especially for those in big cities like San Francisco. The "Globe At Night" project invites people from around the world to take a few minutes in the next 7 days and look at one of the most beautiful constellations in the sky, Orion, and simply report how much of it you can see. It's easier than you think. And it's a great family project to show kids what you can see in the night sky.

The Globe At Night website provides all of the details, but in summary you compare what you see in your sky (your backyard, rooftop or any other convenient observing location) to a series of images on the Globe At Night website. By finding the image that best matches your view and reporting this on the website, you are helping to gather data from cities around the world on the relative light pollution in the sky. The constellation Orion contains stars of varying brightness, and depending upon the darkness of your skies, you will see more or less of these stars. The charts on the Globe At Night website show you Orion with differing "magnitudes" of stars, so for very light polluted cities you might only see the 1st and 2nd magnitude stars, whereas in darker skies you will see 3rd, 4th, or even 5th and 6th magnitude stars (the higher the number, the fainter the star).

Join the worldwide "Citizen Scientists" supporting this effort to increase awareness of the night sky, and take part. And bring along a friend. It's fun!

The Winter Sky Beckons

The Winter Sky beckons me to stop what I am doing and pay attention, for the view of the heavens in this magical season is unlike any other. Here in San Francisco, when it is not raining (as was the case for most of January through today), the air is dry and the atmosphere clear, giving the casual observer sparkling vistas into the heavens. And as this kind of weather happens with regularity in the winter, and the hours of darkness are at their maximum, it is all but impossible to miss the winter sky.

Evenings right now are dominated by the slowly fading planet Jupiter high in the west at sunset, and the colorful bright stars of Orion high in the southern sky, Canis Major and Sirius to the lower left of Orion, and Taurus and Aldeberan to the upper right of Orion. Facing north, the Big Dipper and Cassiopeia trade places every 24 hours, circling Polaris, the North Star. And later in the night to the east are a variety of treasures in Virgo with Saturn in the vicinity. Two weeks ago the morning sky featured the old Moon passing through Scorpios and Sagittarius, creating beautiful alignments that accented the eastern horizon at dawn.

The most important thing to do, if you want to see these amazing sky spectacles, is to keep your eyes open and look up - - nothing more than that is necessary to be captivated by the spell of the sky. No need for a telescope or binoculars. This time of year the stars dazzle in the night, and appear to be asking all of us to take a moment to contemplate their majesty and come to appreciate the universe, awaiting your view each night of the year.

KFOG Podcast - January 20, 2011

My monthly conversation with KFOG Morning Show's Irish Greg moved from the new Zodiac signs (such as Ophiuchus) to the Aurora Borealis to the big bold winter constellations such as Orion and bright stars such as Sirius. Click here to listen and get inspired to look up at the sky tonight!

KFOG Podcast - April 14, 2010

Winter Triangle

One of the highlights of the winter sky is the Winter Triangle. This shape is a nearly perfect equilateral triangle that shines in the southern sky over the next few months. It includes three of the most brilliant stars in the sky, and it is called an "asterism" because it is not a single constellation, but a combination of stars from three different constellations.

The first and brightest star is Sirius, the brightest star in the night sky. Sirius is close to the Solar Systems (8 light years) and has a slight blue coloration. Sirius is in the constellation Canis Major, the big dog that accompanies Orion. To the upper right is Betelgeuse, a red supergiant star in Orion that is a distinctive orange color. Betelgeuse is so big that if it was our Sun, it would envelop Mercury, Venus, Earth and Mars! And the third star of the triangle is Procyon, in the constellation Canis Minor, the small dog that accompanies Orion. Procyon is actually a double-star system with a faint partner star.

Inside the Winter Triangle you can find numerous clusters of stars. I spent some time looking here a few nights ago and was able to see quite a few of these clusters, even in San Francisco. My backyard has a dark western horizon so by looking through binoculars later in the evening I was able to see quite a bit in and around the asterism. Try this for yourself sometime soon.

Dominating the Autumn Sky: Pegasus

In November, the nights grow longer and the sky changes rapidly. The Summer Triangle gradually fades into the west, and Orion and the winter constellations have not risen in the east to dominate the night sky. Instead, we see the less prominent (but no less beautiful) zodiac constellations of Capricornus, Aquarius and Pisces in the south, and directly overhead the large constellation Pegasus with the very distinctive asterism "The Great Square" in clear view. The sketch of the constellation Pegasus shown here is courtesy of the Battle Point Astronomical Association.

Pegasus is named after the Greek mythological character of the winged horse. Some constellations look a lot like their mythological namesake, but in this case I am always challenged to see the winged horse in the sky. But no matter, the shape of Pegasus is distinctive, and the Great Square makes it easy to find. This time of year Pegasus is high in the eastern sky after sunset and it moves almost directly overhead by 10 pm. I was out in my backyard a few minutes ago looking at it and to best see it I had to sit back on a chair. The Great Square is so striking because, yes, it is indeed nearly a perfect square, but more interesting is that there are virtually no other bright stars inside the square to disturb the shape. All around Pegasus, however, are a good number of bright stars, some of which form the head and feet of the winged horse, while the stars on the north side of the Great Square are actually part of Andromeda. In fact, I use Pegasus to help me find the constellation Andromeda and that points us to the Andromeda Galaxy (but that is a topic for another post).

For an excellent set of illustrations and tour of the Autumn sky, visit this webpage from the Smoky Mountain Astronomical Society.