The June 2026 Conjunction of Jupiter and Venus

We have a wonderful opportunity to watch a grand spectacle of nature, a close encounter of two of the brightest objects in the night sky. A rare conjunction of Jupiter and Venus which will reach its peak on Tuesday June 9th. These two objects are so bright, they will be easy to spot in the western sky after sunset and will put on a show for many days. They will start with a very close encounter on June 9th and continue for the next week with the planet Mercury and additional close encounters with the Moon on June 16th and 17th. 

Conjunction of Jupiter and Venus 

My detailed explanation of this conjunction can be found on my latest Translunar Podcast episode from the Volkssternwarte München, detailing what to look for today and for the next week. 

This article from Sky and Telescope Magazine provides much details where to look and what to expect.

Image courtesy of Sky & Telescope. 

Transit of Mercury on November 11, 2019 - don't miss it !

On Monday November 11 we will have a chance to witness a very unique and special event, a transit of the planet Mercury across the face of our Sun. This is a rare event, happening only 13 times in a century. The next one won't take place until 2032.

What is a transit? It is a precise alignment of the Sun, Earth and another celestial body. In this case, that body is Mercury, the closest planet to the Sun and a fairly small planet. It orbits the Sun every 88 days, and when we have this special alignment with a transit, we are witnessing the proper motion of the planet as it progresses in its orbit around the Sun. Mercury's diameter is 194 times smaller than the Sun so it will in fact appear as a tiny, perfectly round black dot against the surface of the Sun (the Photosphere) and will take approximately 5 1/2 hours to cross from solar limb to solar limb.

Time Lapse of Mercury Transit in 2016

If you want to see this, you will need special equipment that incorporates the correct level of filtering to reduce the Sun's intensity to a safe level, and magnification to make it possible to see the shape of Mercury against the disk of the Sun. Many astronomy clubs and public observatories will host viewing events. Here in Munich, the Volkssternwarte München will be open for the entire duration that the transit is visible from here, starting at 1:35 pm and continuing through sunset which is at 4:39 pm on Monday. We just need clear skies and a proper filter and we can enjoy this unique and rare event.

For general information about the transit and more detailed timing for US-based locations, check out this article from Space.com.

Warning: do not stare directly at the Sun for any length of time, and in particular do not look at the Sun through a telescope or binoculars with "eclipse glasses" as these will not protect your eyes sufficiently. Only observe the Sun directly with a high quality solar filter built especially for a telescope or binoculars.

Image courtesy of NASA.

Close Encounters

Close Encounters

The evening sky features a close encounter with the two inner planets, Venus and Mercury. When two celestial objects align, the visual effect is usually quite brilliant. Venus is 100s of times brighter than smaller and more distant Mercury, but nonetheless the two make an impressive pair this weekend. You'll need a clear view to the south-west just after sunset. Binoculars will make it faster and easier to locate the pair. The two planets will remain in close proximity for several days. And next week, the old Moon and Saturn will also have a close encounter. There's always much to see in the sky.

Happy 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.

New Moon and Mercury at Dusk

Mercury and a Young Moon

Elusive Mercury springs into view as January comes to an end, emerging in the glare of dusk this week. The very thin crescent Moon emerges at the same time, and a careful observer with a clear western horizon (and a good pair of binoculars) will have a lovely sight to enjoy. I enjoy seeing the stars and Moon emerge from the glare of the sunset, and when I have a clear view of the sky to the west after sunset I also look backwards to experience the Belt of Venus as it rises on the opposite horizon and envelops the eastern horizon.

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.

Transitions in the Evening Twilight

Every night, the sky appears a bit different to us, and in June as the long days of summer unfold, the sunset sky changes more rapidly than usual. The trio of planets that dominated dusk are now a pair, as Mercury and Venus climb higher into the west, and the bright stars and constellations of winter rapidly fade from view.

June's evening sky

The bright twin stars Castor and Pollux in the constellation Gemini are dropping gradually into the western sky after sunset, and the later and later onset of darkness combine with the change in position to speed these two stars out of view over the coming days. As they are lower and lower each night, Venus and Mercury will move higher each night and over the next 3 weeks, they will move closer to each other.

As you watch the changing landscape in June, take note of the gradual slowing in the onset of darkness as we approach the summer solstice later this month. The evening sky is a beautiful place to see transitions, and the visiting planets this month provide a fine guideline for this.

The Dance of the Planets - a spectacular celestial alignment

This week is the culmination of a spectacular celestial alignment, creating a rare and beautiful triangle of three planets on Sunday 26th. The planets will be low in the west after sunset, and as the glare of the sunset fades, the three bright dots of light will emerge from that glare, and if you have a good western view, you'll see them for a short window of time before they set.

The Triangle of Planets

Jupiter has been dominating the night sky for months, but each successive night has brought it closer to the time when it slips 'behind' the Sun, from our vantage point, and is shielded from our view. This happens to all of the outer planets throughout the course of a year or two. But by cosmic coincidence, Mercury and Venus are rapidly rising into the sunset sky, as their orbits bring them out of the glare from being 'behind' the Sun, and they quickly pop up into the evening sky. This week, they appear to move higher and higher in the sky just as Jupiter is 'falling' and they cross over in a lovely pattern.

To see this spectacle, head out any evening and look west. The configuration will be changing noticeably each night, and for me, that is the real fun here -- to not only see a rare and unusual alignment on Sunday, but to watch the set up in the days before and after. Here are a number of good links with additional information:

Sky & Telescope Magazine
The Always-Engaging Tony Flanders on SkyWeek
NASA Science Cast

Enjoy the show, and may you have clear skies!

Image courtesy of Sky & Telescope

A Perfect Time to see Mercury

Mercury in February

Mercury is the most elusive of the visible planets in the Solar System, never drifting far from the glare of the Sun, and always on the move. So you should take advantage of the upcoming weeks when Mercury will be well positioned in the sunset sky. Mercury is a small planet so it will not have the bold bright shine of Venus or Jupiter, but it will certainly stand out as a bright speck of light in the dusk sky. Look soon after sunset for a point of light that becomes increasingly bright as darkness sets in. You'll need a good, clear western horizon to see this. But take a minute some evening and spot it, since it won't be this easy again for a while.

Image courtesy Sky & Telescope.

Planetary Conjunction at Dusk: Mars and Mercury

Mars & Mercury

This week, you will have a chance to spot elusive Mercury in the dusk sky, as the fast-moving planet gradually slides into the evening sky for a February showcase. In the first few days of Mercury's evening apparition, it moves past Mars, which itself is fading into the evening twilight. To spot these two planets in conjunction (close encounter) on February 7th and 8th, you will need binoculars or a telescope, and a clear western horizon. The two will form a very close pair for a couple days, and then Mars will continue its fade into the glare of sunset while Mercury will race eastward, appearing higher in the sky for the middle of the month. It will be work to find these two, but a fun challenge if you have clear western skies.

The image shows the view 30 minutes after sunset. The Sun sets in San Francisco around 5:40 pm this week.

Here's a helpful short video clip from Sky & Telescope's Tony Flanders showing how to find the two planets in conjunction, and how to find Mercury during the month of February.

Image courtesy of Sky & Telescope.

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.

Viewing all 5 Visible Planets in one night

As the nights grow longer and the skies darker, we have the chance for the next few weeks to see all five planets visible to the naked eye in a single night. Of course, there are seven planets in our Solar System (not including Earth), but two (Uranus and Neptune) are just too faint to see without optical aid. However, the rest (Mercury, Venus, Mars, Jupiter and Saturn) are spread around the entire sky, adding a lot of brightness to our already-shiny Autumn and Winter skies. This article in the science blog EarthSky is an excellent guide to help you find each planet. Of course, to find Jupiter and Venus you need little guidance because they are so bright, but Mercury, Saturn and Mars will be easier to find with some assistance from a sky map.

And if you are ready to look deeper and see all 7 in one night, here is a chart to guide you to Uranus and Neptune. They are both just west of Jupiter, in the constellations Pisces and Aquarius.

Image courtesy NASA.

Planetary Lineup on May 21st

With all of the talk about May 21st, I felt it would be helpful to guide observers to a genuine, heavenly lineup that will create a beautiful pattern in the morning sky on the 21st and 22nd. During the entire month of May, the four nearest planets to Earth have been creating a beautiful sight in the morning sky just ahead of sunrise. On May 21st and 22nd, Mars, Mercury and Venus form a compact cluster. Bright Venus is the "guide star" to help you find this grouping in the east. You will want to look about 30-45 minutes before sunrise, and you will need binoculars to see Mercury and Mars, but Venus will shine brightly despite the glare of the soon-to-be-rising Sun. Jupiter is also quite visible in the sky, but each day pulls away to the upper right (toward the south-east) a bit more from the other three planets. Note that the image of the view toward the east, which comes courtesy of Sky & Telescope Magazine, demonstrates that astronomers are confident we'll have something to see the morning of the 22nd!

Venus, Jupiter, Mars and Mercury in Conjunction

Four of the five most-visible planets are bunched together in the morning sky, creating beautiful patterns along the eastern horizon at dawn for the next few weeks. Each day the four planets change slightly in position, with bright Venus guiding your eyes to the right spot on the horizon where you can see these four points of light. Use binoculars to find all four planets - Mercury and Mars are much fainter than Jupiter and Venus - and use this amazing animation on the Sky & Telescope website to find the exact pattern as it changes each day. In San Francisco, you will want to look for this between 5:00 and 5:30 am, before the glare of the sunrise washes out the view of the planets.

Five Weeks of Planets in Conjunction

We are entering a period of time in which several planets are going to be in close proximity to each other, creating special alignments called "conjunctions." Mars, Mercury, Jupiter and Venus are all occupying the same region of the sky from our Earth-bound point of view, and as these planets and our own planet are all in motion around the Sun, the pattern we see in the sky changes quite a bit from one night to the next. At this time, all of these planets are emerging from the glare of the brightening dawn sky, appearing in the east just minutes before sunrise. Therefore, the initial conjunction on April 19th is best visible with the aid of binoculars. But this is just the start of a five week period in which these planets move very close to one another, creating a beautiful series of patterns for the early morning observer.

Our planet moves nearly 2 million miles per day in its orbit around the Sun. The planets are also moving at high speed around the Sun in their respective orbits. Mercury and Venus move the fastest relative to Earth, and because of their unique position inside the orbit of Earth, we see their changing locations in the early morning just before sunrise, or in the evening just after sunset. The other planets, including Mars and Jupiter for the next few weeks, move more slowly from our point of view and move more steadily from east to west from one morning to the next. I'll be posting a regular series of updates over the next month as the various conjunctions come and go. The important thing for the observer is to find a good eastern horizon, dust off the binoculars, and be ready to get up just before sunrise to see these cosmic alignments.

Jupiter and Mercury: Prograde and Retrograde Motion

Elusive Mercury makes an appearance for the coming weeks in the evening sky, slowly progressing toward Jupiter as the two planets share the same space (from our point of view) just above the setting Sun. Although Jupiter is considerably farther away from Earth as Mercury, Jupiter's massive size more than makes up for that distance and makes it appear to us as a much brighter light on the horizon.

As Mercury rapidly arrives in the evening sky, it changes its location each evening quite a bit, and before long will be aligned with Jupiter, setting around the same time as Jupiter toward the end of March. As it reaches this point, it will then change its daily direction across the evening sky and move rapidly westward toward the Sun, something called "retrograde" motion. For a few weeks, people will say that "Mercury is in Retrograde" which is, from an astronomical point of view, very normal behavior for Mercury every few months. However, for many who follow astrology, this can be a very troubling time. Perhaps seeing Mercury with your own eyes changing location and moving gracefully across the sky, first in prograde motion (the basic motion of planets across the backdrop of stars, eastward), then in retrograde, will make its impact a little more friendly. Try it out for yourself and see.

A Must See: Four Planets and the Moon

This week the sky features four of the brightest planets in a beautiful lineup in the sunset sky. The illustration on the left, borrowed from Sky & Telescope Magazine, demonstrates how the planets all align themselves in a path across the sky known as the Ecliptic. This line in the sky, actually a gentle curve from west to east across the south part of the sky, is the plane of the Solar System as viewed from our observing platform on Earth. We see fast-moving Mercury close to the Sun, then Venus, Mars and Saturn, a most impressive line-up.

To set this into perspective, the young Moon emerges from the glare of the Sun on Tuesday 13th, moving somewhat parallel to the Ecliptic but each day a bit farther south of the Ecliptic. This is because the orbit of the Moon around the Earth is slightly inclined to the rest of the bodies in the Solar System. And as we just had a Total Solar Eclipse on Sunday, the Moon is following a path away from the Ecliptic into what is called the "descending node" south of the Ecliptic.

I will be talking about this at the California Academy of Sciences at their Nightlife event this Thursday in Golden Gate Park. If you are in or near San Francisco, please join me on the roof for Star Tours!

Seeing Mercury in the evening sky

Mercury makes its way into the evening sky, visible shortly after sunset for the next few weeks. The fleet-footed planet never strays far from the Sun from our point of view, so we get glimpses of Mercury in the evening, then the morning before sunrise, and again in the evening several times a year. Right now Mercury is going to be easy to find because it will move near Venus this week. Venus is the bright evening "star" in the west, shining through the glow of dusk, and Mercury, although dimmer, will be fairly easy to spot now that you know where to look.

Planetary Motion

The morning sky continues to be a busy place, showcasing just how much action is taking place in the Solar System. Saturn, a relatively slow moving outer planet is gradually rising up in the east, emerging each morning a minute or two earlier so that it will soon be a true morning star. As it graces the dawn sky just ahead of the sunrise, it is encountering the two fast-moving inner planets, Venus and Mercury. This week they have close encounters and beautiful alignments that will be a sight to see. The illustrations provide a sense of how far Venus and Mercury move over the course of just a few days. The passing of the waning Moon on the mornings of the 15th and 16th add a nice touch to an already impressive lineup of Solar System objects.

Morning Spectacle

Three planets make a nice showing in the early hours of the morning this week, with Mercury and Saturn having a close encounter. Autumn mornings are particularly interesting here in San Francisco because the weather is generally more reliable and the first light of dawn comes so late in the morning -- right now around 6:45 am with sunrise around 7:15 am. The view in the image shows what you can expect to see this week as Saturn and fast-changing Mercury line up on Thursday morning October 8th. All of this will stand in stark contrast to bright Venus, the brilliant beacon dominating the eastern sky in the morning.

Later this week there will be another amazing event in the morning sky. Stay tuned!