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. 

Observing Tips for the Moon

Our lovely Moon is a steadfast companion, a glowing orb that faithfully accompanies us in our journey around the Sun every year. The Moon presents us many facets in its 29-day journey around the Earth and is a wonderful object to look at with visual aid such as binoculars or a telescope. I recorded a podcast to share some insights about our Moon and some tips how you can really savor the view. The podcast is part of the Translunar series recorded for the Bavarian Public Observatory nearby where I live in Munich, Germany. 

"Observing Tips for the Moon" on the Translunar Podcast.

Image courtesy of NASA 

Lunar X and V on October 21st

 

The Moon is a fantastic target for anyone with a telescope or binoculars. There is so much richness to see and on any night the Moon presents an ever-changing landscape, each night different from the previous one. I particularly like first and last quarter moons, as you get a side view of the terminator and can observe the long shadows in the craters. But those shadows and the rapidly changing lighting effects on and near the terminator create striking patterns for those with a good telescope. 

Lunar X and V

The Lunar X and V are two striking patterns that appear monthly on the surface of the first quarter Moon. Visible through a telescope at moderate magnification, these two patterns are visible for a few hours, one after the next, but of course you need to have the good luck of the Moon being above the horizon at that exact time each month. So it is a somewhat rare occurrence and a fun target for amateur astronomers, or just about anyone who wants to put in the time to find it. Enlarge the image to the right for a close-up look. 

This month the view is favourable where I live, here in Munich, Germany. On Saturday October 21st the X and V features will be visible just at sunset and for an hour or two afterwards. I will host a star party in the Englischer Garten in Munich for the public and I hope that many will join to see this unique spectacle.  

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.

Venus passes through the Pleiades - April 2-3-4

Every eight years the path of Venus, as viewed from the Earth, crosses directly through the Pleiades star cluster. On April 3rd the bright 'evening star' will be directly in the center of the Seven Sisters, or Pleiades, and it will be a very fine target through binoculars. It can be found for the first 3-4 hours after sunset, due west. Venus is by far the brightest object in the evening sky so you should have no problem finding this.

Venus passes through the Pleiades

I just checked this evening (Thursday April 2nd) and already the juxtaposition of extremely bright Venus and the blue-white shimmer of the Pleiades is remarkable through my 10x50 binoculars. The good news is that the bright first quarter Moon to the upper left of Venus does not cause any issues seeing this spectacle, and given the brightness of both Venus and the Pleiades (as seen through binoculars) this will be visible even with the light pollution of a big city. But ... you will need binoculars to truly appreciate this.

The best view will be on Friday April 3rd, but it will also still look quite impressive on Thursday April 2nd and Saturday April 4th.

More information in this Sky & Telescope article.

Image courtesy of NASA APOD and Fred Espenak.

The Moon: where is it going to rise tonight?

Moonrise in San Francisco

An old friend, Scott in San Francisco, posted a question on Facebook and it caught my attention. He illustrated a quandary that he faced when observing the moonrise in San Francisco on two consecutive nights and wondered why the two locations were so different. Here is what he wrote: "I am puzzled ... Can someone explain how the moon changes its position so radically in one day? I created a hand drawing of the moon, its location, and time as it rose over the San Francisco skyline the last two nights." There are two (well actually three) factors at work here.

Before we dive into the specific factors, let's review the basics. The moon, like the sun, rises in the east and sets in the west, but of course the precise point of sunrise varies throughout the year. The sun rises either north of east in the summer when the days are longer, or south of east in the winter when the days are shorter. The full moon, which Scott was observing when he sketched the images last month, has an opposite behavior compared to the sun ... that is, the moon is in the opposite part of the sky compared to the sun and as such, in the winter the moon rises north of east (when the full moon nights are longer) and south of east in the summer (when the full moon nights are shorter).

In addition to that macro change in the position of the moonrise compared to sunrise throughout a year, there are daily changes to the position of the moonrise. The moon, being much closer to Earth than the sun, moves rapidly in its 29 day orbit around the Earth and from one day to the next is approximately 12 degrees further eastward in comparison to its location the night before. That is the main reason that a rising moon rises approximately one hour later each evening, and the primary factor that is illustrated in the drawing above. The Earth has to turn more to get to the place where the moon has moved, in this case from 8:00 pm to 9:00 pm/.

Moonrise position changing

But there is a subtle secondary effect that Scott captured in his sketch. That is that the location of moonrise is quite a bit shifted on the horizon. In this case, it is to the south from one day to the next, not just a later moonrise time but also a point on the horizon that is south of the previous day. What is happening here is that the moon's path around the Earth is quite similar to the sun's path around the sky and that is a path that follows the zodiac band around the sky, something also called the ecliptic. Because the moon follows this path, and in this special circumstance in which a full moon is observed on successive nights, the winter full moon appears to rise further and further south on consecutive nights until it finally moves to last quarter moon phase and then it will resume its travels northward (north of east) as it rises late each night. In fact, the moon is simply moving across the known Zodiac constellations of Virgo, then Libra (see image on left), and eventually Scorpius and Sagittarius, all of which are low on the horizon and low on the ecliptic, and therefore are part of the reason why the moon rises further and further south of east on consecutive nights in the winter. The image shows how the moon moves across the Zodiac from night to night, but it will take some creativity to juxtapose this on the eastern horizon to fully understand why the moon is further south of east on consecutive nights. Think about it. It requires some big picture thinking.

There is a third factor for the change in the location of moonrise on consecutive nights which is based on the moon's orbital inclination, but that requires fairly expert knowledge of celestial mechanics to fully comprehend so we will save that for another time ... or a star party.

Today is the full moon, March 9th, 2020. You can try to reproduce Scott's experiment now, looking closely at the eastern horizon and locating landmarks where you can spot the moonrise on consecutive evenings. For the next 3 or 4 evenings the moon will rise about an hour later each evening, and also will rise at a point further to the south of east compared to the night before.

I wish you clear skies and happy viewing.

Geminid Meteor Shower 2019 & Full Moon

Geminids

Everyone loves a good meteor shower. And the Geminids, which peak mid-December, are one of the best each year. But all meteor showers are subject to the whims of our own Moon which can substantially disrupt viewing. The full Moon is a delight to look at, both naked eye and through a telescope. But it casts a significant glow in the night sky and that means that the fainter meteors in a meteor shower will be virtually impossible to see. With the Moon full or nearly full from December 11th to the 14th this year, it will be shining brightly exactly when the Geminids are expected to reach their peak on the 14th.

Nevertheless, I take encouragement from this excellent article from the American Meteor Society that  provides some good tips for seeing a few of the brighter Geminids this year. Good luck, dress warm, and clear skies!

Image courtesy of Wikimedia Commons / Asim Patel

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.

Supermoon on November 13 and 14

How much bigger is a Supermoon? 

The natural cycles of the cosmos brings us many interesting sights in the night sky and our closest celestial neighbor, the Moon, is always one of the best and brightest as it aligns with the Sun for an eclipse, or a planet for a spectacular conjunction. Sunday and Monday November 13 and 14, the Moon reaches its closest point on its orbit around the Earth at nearly the exact same time as it reaches its full phase, creating a Supermoon. This special situation happens every year or so, but this time the Moon will be a slight bit closer to the Earth, making this the closest Supermoon since 1948. The next Supermoon of this stature will arrive in 2034. So if you have clear skies Sunday or Monday, make a special effort to get out and see this ever-so-large object in the sky, 14% larger than it is when the Moon is at its farthest from the Earth.

The exact moment of the full Moon is Monday morning at 5:52 am pacific time, and the closest approach to the Earth (perigee) at 3:22 am, a bit earlier that night. So if you want to see the biggest and best view that will be early Monday morning November 14th. However, moonrise on both the evening of the 13th and 14th should be incredible so don't feel obligated to see it at the exact moment if you prefer sleeping in a warm bed! Or if you happen to live in Europe you can simply watch the moonrise on the evening of Monday 14th and you'll be all set. The exact time of moonrise can be found here, depending upon your location.

Here are some good online resources to learn more: 

Sky & Telescope Magazine

EarthSky.org

NASA

San Francisco Amateur Astronomers

Image courtesy of Wikipedia

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.

The Moon and Jupiter

Full Moon and Jupiter

Jupiter recently reached opposition, appearing at its brightest and traversing the night sky from sunset to sunrise. It's the most obvious beacon in the night sky, far outshining everything around it. That is, except for the Moon which of course is the brightest object in the night sky. This week as the Moon moves through its full phase, it has a close encounter with Jupiter on the evening of March 21.

By the way, since the Moon is full this week (on Wednesday March 23rd) just after the Spring Equinox, it will rise due East and set due West on that day, roughly mirroring the position of the Sun six months hence, on the Fall Equinox.

Full Moon Setting and Other Morning Sky Wonders

Planetary Lineup

The Full Moon is a delight to see rising in the evening, but as we have long nights in November and December, I find the moonset to be equally engaging. This morning the Moon was blazing in the west an hour before sunrise (around 6:00 here in the San Francisco Bay Area) and the 'belt of Venus' shrouded the horizon just below the Moon. And facing east, the recent planetary conjunction has stretched into a planetary lineup across the sky.

If you are up early and the sky is clear, take in the sights facing east and west. You won't be disappointed.

Image courtesy Sky & Telescope.

This Week Facing East

This Week Facing East

The dawn sky is punctuated this week with a spectacular lineup of some of the brightest celestial objects in the heavens. The waning crescent Moon is the centerpiece of the eastern horizon in the hour before sunrise, shimmering next to Venus, currently a blazing gem of a ‘morning star’ due east, piercing the darkness of the horizon well before the first light of day, and remaining brilliant until the glow of sunrise washes out the planet.

Fall is a great time for seeing the morning sky since the days are getting shorter and the darkness lingers longer each morning, giving early risers like me a chance to get in some astronomy before starting my day in earnest. Each morning this week as I step out of my front door facing east, I await the spectacle of some of the brightest stars in the entire night sky and the wandering visitor Moon this week, taking the stage with Venus to amaze me and all who take a moment to savor this sight.

Image courtesy Sky & Telescope. 

Approaching a Conjunction

Evening Trio

Each day the planets Venus and Jupiter are drawing closer together in the evening sky, as Jupiter gradually sinks into the western twilight and Venus holds course. The two will have a close encounter (conjunction) on June 30th, but already the two are a striking pair in the evening sky, made more interesting by the waxing crescent Moon this weekend. Look for the trio just after sunset (around 8:45 pm in San Francisco) and watch them become more and more brilliant as the sunset sky turns to dusk and eventually to darkness.

Image courtesy of Sky & Telescope.

Moon and Venus in the West

lender Moon and Venus

Wednesday January 21st, a very slender young Moon and Venus form a compact group immediately after sunset. You'll need binoculars to spot this grouping, as the thin crescent Moon will be easily lost in the glare of the sunset sky, but bright Venus should be easier to spot. There's something magic about the sight of the thin crescent Moon, just barely glowing as a small bit of its illuminated side is visible to us, and that small light has to be seen through the glowing atmosphere with the refracted sunlight still filtering through it.

In San Francisco, the Sun sets around 5:20 pm so the view here should be accurate for 6:00 pm. You'll need a clear horizon due west to see this. Best of luck and happy viewing!

If you miss the view on Wednesday, look again on Thursday as the Moon sweeps past Mars.

Celebrate the Moon - Saturday September 6th

This Saturday is International Observe The Moon Night. Where will you be for this special evening? I'll be conducting sidewalk astronomy in front of the Exploratorium in San Francisco along with other astronomy enthusiasts. The Moon will be a few days away from another Supermoon, and if the skies cooperate, we should have a lovely view of Earth's natural satellite in gibbous phase between first quarter and full. Click the link for more information on International Observe The Moon Night. Hope to see you at an event.

The Start of a Lunar Cycle

Young Moon movements

Each time a lunar cycle begins, I look forward to each evening to see where the Moon is going to be, starting with a dark night sky at New Moon, and over the course of a week enjoying the waxing crescent of our celestial neighbor as it grows into First Quarter. Along this journey, I await alignments and close encounters, and in the early days of the current lunar cycle there are many objects in the path of the Moon.

Moon & Mars

New Moon is on Friday June 27th, and the first chance to spot the young Moon is Saturday 28th (which, if sighted, will start the month of Ramadan). The Moon on the 28th is very near Jupiter and both set shortly after sunset. It will pass very near Regulus in Leo on July 1st, and as it then travels across the ecliptic it will reach First Quarter and have a close encounter with Mars and Spica, covering Mars for a short while on July 5th, but this event will not be visible from North America.

After passing by Mars, the Moon will gradually move next to Saturn. More on that in my next blog post.

Images courtesy of Sky  & Telescope.