Skies were clear enough last week for some fantastic views of three bright planets and the moon that joined them. Now, these next two weeks, we get to follow the drama of two final planets passing each other — Venus and Saturn.
The peak event in this planetary show is the close “conjunction” of the two worlds next Tuesday. And there is a rather different kind of encore scheduled for the following Friday: the Geminid meteor shower, often the best of the annual showers but this year partly washed out by a bright moon.
Last week’s prelude to our Venus-Saturn meeting: Last week started with Venus and Jupiter at their closest together. These two brightest of all planets were separated by only the width of your little finger at arm’s length. On Monday of last week, the two were almost side-by-side when about the width of your thumb at arm’s length apart. I almost said “beautiful” out loud when I stepped out my front door and first saw them.
By Thursday, Jupiter was deeper in twilight, half a fist-width lower right of Venus. But that sunset brought us the long-awaited Thanksgiving pairing of the crescent moon with Venus.
Around sunset on Thanksgiving it was already possible to look low in the southwest and see a wire-thin slice of pale moon with a concentrated dot of light a few moon-diameters below it — Venus. In the early minutes after sunset, a few gorgeous pink clouds and pink airplane trails provided an accompaniment to the moon and Venus. As the sky darkened, the moon became so lustrous it appeared thicker and Venus became a veritable lantern.
What would Friday’s view of this section of the sky be like? There were numerous narrow rows of pink clouds for awhile, then more clearing and the sight of the moon surprisingly far to the upper left of Venus — more than a fist-width at arm’s length.
This demonstrated how fast the moon — much closer to us than the planets — moves in its orbit in 24 hours. But there was an added beautiful touch — quite close to the upper right of the waxing lunar crescent was the easily visible point of light that is Saturn.
Venus and Saturn pass each other: If you have a view almost all the way to the southwest horizon Tuesday night, and skies are clear, go out around 5:15 p.m. and look for our three bright evening planets about equally spaced in a slightly crooked line. In the middle of the line is very bright Venus. Well to the lower right of Venus in still-glowing sky is bright Jupiter. Well to the upper left from Venus is respectably bright Saturn.
But the positions of the planets are changing. Jupiter appears lower each night, and by next week is lost from view, setting too soon after the sun. Saturn also comes into view lower with each passing night but Venus appears higher.
Therefore, Venus and Saturn keep appearing closer together each night — by Saturday, down to less than 5 degrees apart, which is half a fist-width at arm’s length. On the following days the gap between Venus and Saturn shrinks by about a full degree each day.
Next Monday, Saturn is straight above Venus. Next Tuesday and Wednesday, Saturn is upper right from Venus and the pair is at their minimum separation, less than 2 degrees apart. Can you on those nights manage to get both planets into a telescope’s field of view at a high enough magnification to see the blazing globe of Venus with the paler globe and rings of Saturn?
A few Geminid meteors by moonlight: The moon is full on the night of Dec. 11 into Dec. 12. Two nights later — from the evening of Friday, Dec. 13 until near dawn on Saturday, Dec. 14, we should have our best chance to see some “shooting stars” flying away from the constellation Gemini. The moon will still be bright and up almost all night, but we might catch a few long-path Geminids around 6 to 7 p.m. (before moonrise) and maybe up to 10 or 20 bright Geminids per hour by late evening.