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.