The Real Planetary Parade

I love to see planets in our night sky. They are wonderful. They are wanderers. In motion, always gently sweeping across the sky, often the brightest objects in the sky and certainly some of the most colorful and interesting, both to the naked eye and in a telescope. I've recorded a podcast for the Translunar series to share some ideas of what you can see right now and for the next few months, with a Mars challenge built in.

And for those of you looking for a big “Planetary Parade” on January 25th, well, I am sorry to say, January 25th will look a lot like January 24th, and 26th, and the 27th, and so on. It’s just hype and to be honest, I think it is just something someone created to drive clicks to their website. But don’t be disappointed: the reality behind the hype is that there really are lovely planets spread across the night sky and there are wonderful things to see and enjoy for the coming weeks and months. Have a listen to my podcast and you will get a clear and thoughtful explanation of the planets, what to see, and what to look for night after night. 

The Great Conjunction of Jupiter and Saturn - Dec 21st, 2020

We will witness a very rare and beautiful spectacle in the coming days. On December 21st, Jupiter and Saturn will be less than one-tenth of a degree apart from each other as seen from Earth, a rare alignment that happens only every 400 years at this extremely close separation. 

The Great Conjunction

Great Conjunction: Conjunctions occur often in the heavens, as heavenly bodies pass near each other, on in the less common scenario where the Moon covers stars and occasionally planets, and as planets and asteroids cover stars. In any case, a conjunction is usually a fascinating thing to see, particularly up close if you have binoculars or a telescope. When Jupiter and Saturn pass near each other every 20 years, we have a 'Great Conjunction' in which the two massive planets are very near each other. But every 400 years, the alignment is extremely good and we have both objects in one telescopic field of view, as portrayed in the image to the right. 

How to See It: The two planets will be visible only for a short while after sunset, and you will need a clear view to the west to see this. Look directly to the southwest of the point of sunset an hour after the sun goes down. If you have a telescope or binoculars, this is definitely the time to get them out and put them to work. If you can, look for the pair on Saturday 19th or Sunday 20th to get an idea where to find them. They will be in roughly the same place on the 21st, but through the telescope or binoculars the difference from one night to the next will be dramatic. 

Learn More: There are excellent articles online if you want to learn more about this rare and exciting event, on Scientific American or Earth-Sky. I find all of the detailed planetary geometry fascinating, and fun to understand how such alignments occur and can be accurately predicted. 

I wish you clear skies and happy viewing! 

Image courtesy Earth-Sky. 

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.

A Fall Triangle

There are popular alignments of the stars that mark summer and winter, but not in the fall ... that is, until Thursday October 22nd when we will have a brief but impressive 'Fall Triangle' as a result of the waxing Moon passing near Jupiter and Saturn in the evening sky. To see this you will need a clear view to the south, but the three objects are easy to find and a pleasure to view all in one compact triangle. If you have binoculars the view will be even more spectacular. The day before and the day after the Moon will no longer be close enough to form the triangle. So take a minute to savor the sky on the 22nd and you won't be disappointed. 

As an added bonus, take note of the position of Jupiter and Saturn. If you pay close attention over the next two months, you will see the gap between them closing day by day. Jupiter is heading for a conjunction with Saturn that will culminate in a very close encounter in late December. Keep your eyes on the sky! 

Image courtesy Sky & Telescope. 

Late Summer Waxing Moon

Who doesn't like looking at the Moon? It's such a treat for everyone, and is a lovely sight. For us Northern Hemisphere dwellers, there is a unique period of time each year in the late summer when the waxing Moon plays out across a low swath of southern sky, never getting very high into the sky. That unique period of time is now, and the Moon is making things more interesting by passing close to Jupiter and Saturn. 

For the last many days I've watched the waxing Moon emerge from the new phase into a thin crescent and then slowly toward first quarter. All the while it hugged the southwestern horizon, keeping low in the sky and making it more challenging to find. Now the phase has advanced to gibbous (between first quarter and full Moon) and all the while, the Moon only gets high enough to be seen if you have a clear view to the south. And for me, when I see this low-flung Moon, I know it is late summer. There is a technical reason for this. The waxing phases of the Moon occupy the sky where the Sun will be for the coming six months ... and that will be in the Fall and Winter seasons where the Sun does not rise too high above the southern horizon. There is a beautiful symmetry to the Sun and Moon and since we have one complete lunar phase every 29 days, we can see the entire flow of the seasons every month if we know how to look at the Moon. 

Over the past several years the late summer sky has featured Jupiter and Saturn low in the south. This year Jupiter will overtake Saturn in a series of 'conjunctions' which have already started, and will run their course by the end of the year with a spectacular alignment of the two planets in December (mark your calendar for Dec 21st). Saturn moves around the Sun very gradually from our point of view, and Jupiter faster but still quite gradual from year to year. The effect of these gradual movements is that these two giants have been lurking low in the southern sky during the Summer for the past years and for the coming years ahead. So as I've observed this unique time of year when the waxing Moon traverses a deep southerly course in the late summer, it's had the added beauty of a monthly encounter with Jupiter and Saturn. That will happen this week, on Friday 28th. You will need a clear view to the southeast to really enjoy the spectacle. And who knows ... perhaps you will discover this lovely configuration and the low waxing Moon in late Summer as something you will look forward to every year. I sure do. 

Image courtesy of Sky & Telescope. 

Moon and Planets grace the morning sky

Moon and Planets - May 2020

This week, as the Moon passes through its waning phases, it will form some engaging patterns with three planets that are currently visible in the early (pre-dawn) skies. See image showing the change of location of the Moon from one night to the next, and the gentle interplay with Jupiter, Saturn and Mars as the Moon travels in its orbit around the Earth another 12 degrees eastward each day.

Jupiter has been gradually moving eastward as well, albeit considerably slower than the Moon. In fact, it takes Jupiter one full year (on Earth) to move the same 12 degrees eastward as the Moon does every day. And in addition, when we view Jupiter and the other outer planets from our view aboard spaceship Earth, we see a peculiar motion that takes Jupiter westward for a few months before continuing its eastward journey. We call this reverse motion 'retrograde' motion and in fact Jupiter is just now starting into retrograde and will return into the constellation Sagittarius for the summer before returning its eastward journey past Saturn into Capricornus at the end of the year.

This summer, Jupiter and Saturn will rise earlier and earlier and be visible the entire night from July onwards. But for now (in May) you will need to be up after midnight and before the break of dawn, around 4:30 am here in Munich, if you want to see this lovely morning alignment of the Moon and planets. I wish you clear skies and happy viewing!

Image courtesy Sky & Telescope.

Planetary Alignments

Jupiter, Venus, Saturn and the Moon put on a good show this week in the evening sky. To see this you will need a very good western / southwestern horizon and clear skies. As Jupiter and Saturn recede into the sunset sky a bit lower each evening, Venus is racing out of the glow of the sunset sky and emerging as our evening 'star' for December and the coming months.

Of course, the planets and the Moon all occupy roughly the same path across the sky, so when planets align the Moon is often not far away. On Wednesday and Thursday and Friday the Moon will closely pass below and then above the Jupiter-Venus conjunction and then a day later, Saturn. The young Moon is always a treat to view in binoculars or a telescope, and having Venus and Jupiter and Saturn nearby will make the apparitions all the more exciting. The challenge here is that you will need to look very shortly after sunset, because within an hour most of these objects will set. Daily sky maps are here.

Clear skies!

Image courtesy of Sky & Telescope.

Follow Up Note: on November 28th I was on a plane flight above Germany and took this photo looking south west during the flight. The Moon is nicely placed between Venus and Jupiter. Venus is quite easy to find but Jupiter takes more work. Note that the Sky & Telescope diagrams (above) are based on the view from the US, so the Moon is past Venus, whereas I saw the alignment many hours earlier when the Moon was still between the two planets.

Three Planets in the Sunset Sky

Three planets are visible in the west just after sunset. Saturn is on a gradual fade into twilight and will disappear from view later this month, following the path of the zodiac constellation Sagittarius and the center of the Milky Way as the Earth's steady motion around the Sun carries us from the summer and fall constellations into the winter skies.

Mars, Venus, Saturn

Venus is the brightest object in the west for the coming months, maintaining its position as a bright beacon above the horizon for an hour or two after sunset. Both Venus and Mars are not 'pulled' into the western horizon in the same way as Saturn because they are much closer to the Earth and more nimble, moving steadily east in their orbits and keeping pace with the Earth's own motion. For that reason they remain in the evening sky after sunset with Venus eventually dropping out of sight late this winter and Mars holding its western location until nearly summer.

To see any of this you will need a clear and unobstructed western horizon. A pair of binoculars will enhance the view. And clear skies!

Moon, Mars and Saturn

Mars, Moon and Saturn

Mars and Saturn are moving toward opposition (in May and June, respectively), which means they are going to be rising earlier and be more visible in the evening sky, and will be brightening over the weeks ahead. These planets are in Scorpius and Ophiuchus, low in the south in the latter part of the evening through the early morning hours.

The waning Moon passes through this region over the nights of 24-25-26 April and should be a nice picture mixed with orange Mars, yellow Saturn, and the red giant star Antares in Scorpius.

Hope you can spot these two gems and the Moon as they line up for a few days, making the sky that much more interesting to see.

Image courtesy of Sky & Telescope.

Saturn Fades in the West

Crescent Moon graces Saturn

After a long and glorious run in the night sky, Saturn is gradually fading into the west and will fade out of view in the coming weeks. Just before it is gone, the waxing crescent Moon will pass near it this week. For me, the evening sky with a young crescent Moon is always quite beautiful, a gentle curved glow that sometimes includes 'Earthshine' on the unlit part of the Moon visible to Earth.

Find a good southwestern horizon this week and enjoy the Moon as it graces the planet Saturn. Get out your binoculars or telescope for maximum effect!

Image courtesy Sky & Telescope.

Red 'Stars' and White Moon

Slender Moon, Mars and more

For the next week, the twilight sky will feature a close alignment of two bright shiny red objects, Mars and Antares, and the slender Moon wending its way through the southwestern sky. The Moon encounters the ringed planet Saturn on Saturday 27th and then brackets the close pairing of orange-red Mars and the red supergiant star Antares in the constellation Scorpius. This first lunar cycle of autumn should start out beautifully with the waxing Moon and some lovely alignments. Look south and west shortly after sunset each evening for the best viewing.

Image courtesy Sky & Telescope.

Four Planets at Dusk

As the Sun sets this week, we have a very nice view of four planets visible in an arc that spans the entire sky. About 45 minutes after sunset the sky is nicely fading to dark (around 8:45 to 9:00 here in San Francisco) and the four brightest objects in the sky take the stage, spanning from the northwest to the southeast. Nearest to the Sun is elusive Mercury in the northwest evening sky above the sunset point. Looking up and to the left you can't miss brilliant Jupiter, gradually dropping lower and lower in the evening sky in the constellation Gemini. Higher up and farther to the left of Jupiter is orange Mars, shining among the bright stars of Virgo. And finally in the opposite side of the sky from sunset is Saturn, emerging from opposition in the southeast part of the sky among the faint stars of Libra. From horizon to horizon the planets dominate the dusk sky, so if you have a good horizon step outside as the sky is fading and enjoy the four bright pinpoints of light that mark the path of the Solar System. In the fading light of dusk these are the first four objects you will be able to easily spot.

More details on Sky & Telescope and on Earth Sky.

Saturn Arrives / Mars Reverses Course

Mars in Retrograde

It's a good time to enjoy planets, as Mercury, Jupiter, Mars and Saturn all occupy the May skies. Saturn reaches opposition on May 10, rising as the Sun sets and remaining visible all night next to the bright pair of stars that top the scales of Libra.

Mars has been in retrograde motion (reverse motion) across the constellation Virgo during April and in early May reaches the end of retrograde and returns to prograde motion, moving back toward the bright star Spica. It's interesting that Mars was near Spica during April's 'Blood Moon' eclipse and in the course of a few weeks moved rapidly westward toward the star Porrima. Now that it has completed its retrograde sweep it returns to Spica in July and continues eastward toward a conjunction with Saturn in Libra in August.

Image courtesy Sky Safari.

Planets and Comet ISON

Lately while trying to view Comet ISON, I have been up early looking at the sky and enjoying the view to the east as stars and planets emerge from their sojourn around the Sun and start their trek across the sky. Saturn had been an evening sky object in the summer, disappeared from view in early fall, and is now arriving in the morning sky, with fleet-footed Mercury keeping it company.

These two planets are just barely visible this week in the glare of the Sun's early light, and are helpful markers in the quest to find Comet ISON. However, as ISON races toward its close encounter with the Sun on Thanksgiving day, it is pretty much out of sight, lost in the sunlight that bathes the eastern horizon.

KFOG Broadcast - August 8, 2013

Today's discussion with Greg Gory and the Morning Show team at KFOG includes the Perseids, the International Space Station, Star Parties and Saturn. Listen here. 

Saturn at Opposition 2013

Typical Telescope View of Saturn

Saturn reaches a special moment in the sky for us Earth-bound viewers, a time when conditions are most favorable for viewing the 2nd largest planet in the Solar System in all its glory. Opposition is the time when the planet is directly opposite the Sun, from our Earthly point of view. That means a few things: (a) it is at its closest to Earth, and therefore brightest for the year, (b) it is visible all night, rising just after sunset and setting just before sunrise, and (c) it is illuminated straight overhead from the Sun, much in the way we view a full moon.

For the city dweller, Saturn is an easy object to find, outshining most of the stars in the sky except nearby Arcturus, and its rival planet Jupiter (which is slowly fading into the west earlier each night). Saturn glows a yellow-white hue, in contrast to another nearby bright star, Spica. To find Saturn, it rises right after sunset this evening and for the foreseeable future, and glides from the south-east to the southern sky, and then across to the south-west after midnight.

If you have a telescope, now is the time to put it to work, as the view of Saturn will be at its finest. Wait a little while after sunset until Saturn is higher in the sky, less susceptible to atmospheric effects. The ring system is tilted 18 degrees toward Earth, so the view is quite good, and as anyone who has seen Saturn in a telescope will attest, the rings are amazing to see with your own eyes.

Here are two good resources for learning more about Saturn at opposition: Sky and Telescope's fine article, and EarthSky's tips how to find Saturn using the Big Dipper, Arcturus and Spica.

Image courtesy Wikimedia Commons

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.

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.

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.