Mercury and Venus

The two inner planets will rendezvous in the sunset over the next few days. Venus appeared in the sky a few days ago having just emerged from superior conjunction. Mercury will emerge quickly from the solar glare to pass Venus only 10° from the Sun. This conjunction will be quite low and a bit in the bright glow of sunset, perhaps somewhat challenging to spot.

This evening the two will be about 2° apart, and will quickly converge. On July 16th the two will be only 32′ apart, about the diameter of a full Moon. After that the two will quickly separate. Interestingly on the 17th the pair will pass through the M44 star cluster, though perhaps it will still be a bit bright to appreciate this dimmer cluster.

Late in the month this trio of bright planets will continue their dance in a set of conjunctions that lasts into September. The highlight will be on August 27 when Jupiter and Venus will pass within 12′ of each other while Mercury is only 5° away.

Moon and Mercury
The Moon appears as a thin crescent beside the planet Mercury, photo taken from the summit of Mauna Kea on 12Oct2007

Mercury Transit Reminder

Just a quick reminder that mercury will transit the face of the Sun tomorrow morning. You can read full details in my earlier post or check out a decent transit calculator. For observer in Hawaii the transit will already be well underway at sunrise, making this a set-the-alarm-early exercise. My telescope and solar filter are already loaded… Are yours?

Transit of Mercury
The 2006 transit of Mercury, photographed with a 90mm telescope and a Canon 20Da

The Moon, Mercury, and Venus

Tomorrow morning a beautiful trio of two planets and the Moon will rise in the dawn. Venus will rise first at 5:02HST, followed shortly thereafter by the Moon and Mercury nearly together. The trio will form a neat triangle about 6° across. The planets will rise an hour before the light of dawn spreads across the sky and nearly two hours before sunrise.

The Moon and Jupiter

The Moon and Jupiter will rise together this evening of January 26th. The Moon will rise first, around 20:40HST, followed by Jupiter half an hour later at 21:25HST. Over the course of the night the Moon will slowly approach Jupiter, closing to about 4° by dawn.

The following evening, January 27th, the order will be reversed, with Jupiter rising first at 21:21HST and the Moon rising twenty minutes later at 21:40HST, with about the same separation of 4°.

Five Bright Planets in the Dawn

All five planets that are visible to the unaided eye can be found in the dawn for the next few weeks. Jupiter, Saturn, Venus and Mars have been visible in the dawn for some time now. Arriving late to the party is Mercury, just rising out of the glow of dawn. Mercury is headed for maximum elongation on February 7th, rising to 24° ahead of the rising Sun. The line of planets will persist for a week or two after that as Mercury drops back into the glow of dawn after elongation.

Zodiacal Light
False dawn, actually zodiacal light, rising over Mauna Kea
Highest in the sky is Jupiter, shining at -2.3 magnitude and rising before 10pm. Mars rises next, around 1am, seen as a ruddy red object, much dimmer at +1 magnitude. Saturn will rise around 3:30am in Scorpio near Antares, shining at +0.5 magnitude. Venus rises around 4:45am and will be quite obvious, the brightest of the five at -4 magnitude. Last will be Mercury, currently rising just before 6am and shining at +1.2 magnitude. It will rise earlier and earlier as it approaches maximum elongation, rising at 5:20am on February 7th. As Mercury reaches it highest it will be only 4° from Venus.

Together the five planets neatly outline the ecliptic, the plane of our solar system revealed by simply connecting the dots across the sky. As dawn approaches, but before the start of twilight around 6am, look for the zodiacal light, the bright glow of interplanetary dust also seen along the ecliptic.

Venus and Saturn

On the morning of January 8th and 9th Venus and Saturn will be quite close in the dawn.

Moon and Mercury
The Moon appears as a thin crescent beside the planet Mercury, photo taken from the summit of Mauna Kea on 12Oct2007
Tomorrow morning the two can be seen rapidly closing upon each other, less than 3° apart. A slim crescent Moon will be only 4° above Venus making for a lovely trio in the dawn. The morning of the 7th will also feature a nice trio, with the Moon now below the pair, closer to the horizon.

As the pair rises on the morning of the 8th they will be only 32′ apart, easily close enough to fit in the low power field of most amateur telescopes. The morning of the 9th will see the pair again close, only 34′ separation. They will slide past each other much closer, about 5′ apart, but this will not be visible from the central Pacific as it occurs around 11:42 HST on the 8th, while the planets are below the horizon.

Moon, Venus and Saturn

Tomorrow’s dawn, January 6th, will see the Moon, Venus and Saturn in a nice conjunction. A beautiful 12% illuminated crescent Moon will be a bit over 4° above Venus shining brightly at -4 magnituide. Saturn will be another 3° below Venus. As an added accent the bright star Antares will be 6° south of the trio.


I missed the closest approach of Venus and Jupiter. Not for lack of trying. I had set up the telescope and camera in the driveway. A clear afternoon clouded over at sunset, leaving me only glimpses of the planets through a fleeting gap in the clouds. I had time to focus enough to see the crescent of Venus, which promptly faded from sight.

The next evening I am on the summit. No small telescope available, but I did have the camera to record a stunningly beautiful evening atop the mountain.

Venus and Jupiter over the Keck 1 dome

Venus and Jupiter Reminder

A reminder that this evening will see the close approach of Venus and Jupiter. Watching over the last week we have seen these two bright planets growing ever closer in the evening sky.

The closest approach will be about 0.3° tonight, June 30th at 16:14HST. They will be slightly further apart several hours later at sunset.

This is the best opportunity to see the pair at their closest for observer in Hawaiʻi. If you want to see the closest approach you can also try to observe the conjunction in the late afternoon sky. Both planets are bright enough to see in the daytime.

After this the pair will separate slowly and disappear into the sunset glow together.

At their closest the two will be easily close enough to bee seen together in the low power view of amateur telescopes. It makes a fascinating sight to see the two planets together in the eyepiece.