Saturn Meets Venus In Evening Twilight Showdown

Venus (bottom) and Saturn (top) appear above the fog Sunday night Sept. 15 about 65 minutes after sunset. Credit: Bob King

A reader mentioned the other day that I seemed pessimistic about seeing the planet Saturn. You know, he was right. Although our favorite ringed planet has settled into obscurity low in the southwestern sky at dusk, it’s still in the game. I easily saw it with the naked eye last night three fingers (5 degrees) above and left of Venus starting about 40 minutes after sunset.

Saturn swings around Venus this week as it heads towards the western horizon. Venus makes the planet easy to find. Stellarium

Venus was a snap! If you know where to look and your sky is clean and clear, you can easily find the planet when the sun’s still up. But 25 minutes after sunset, it’s already so bright it’s hard to miss.

The moon lights up fog in field north of Duluth Sunday night. Credit: Bob King

Saturn passes closest to Venus this Wednesday Sept. 18 and continues moving west until its retirement from the evening sky later in fall. If you’ve had trouble knowing where to look for the planet, allow Venus to show you the way. Saturn hovers just 3.5 degrees north of Venus on the 18th but will be near it now through Sunday evening. A small telescope will still show the rings with ease.

Lights shining through a tree splay into dozens of separate rays in the fog. Diffraction of light by fog droplets tints the outer parts of the glow reddish-orange. Credit: Bob King

As temperatures dip below the dew point at night, humid air gives rise to fog almost as soon as the sun sets. Last night it filled the nearby fields during twilight and rose and fell in slow waves under a brilliant gibbous moon. Pretty entrancing stuff.

Last night’s gibbous moon made a great backdrop for birdwatching. Credit: Bob King

The moon will be a chubby gibbous again tonight, but get ready for the full Harvest Moon coming later this week. We’ll have more on what makes it so special tomorrow.

I noticed last night while observing the moon through the telescope that the seasonal bird migration is well underway. In just a few minutes of gazing I counted a dozen flapping silhouettes flying past the craters Copernicus, Plato and Tycho. Lots more of these avian lunar transits are in store around the time of full moon for anyone with 15 minutes and a small telescope.

14 Responses

  1. Edward M. Boll

    I suppose if one is careful you could spot Venus with binoculars about 40 minutes before sunset. That is quite a contrast to Pluto which now sets at about 1 AM. But by 10 pm, when absolute darkness has set in this little ”planet” has a low altitude.

    1. astrobob

      A couple days ago I spotted Venus with 8x40s at 6 p.m. Then when I lined it up with a tree it was visible with the naked eye.

    2. Sean

      never mind Venus with binos 40 minutes b4 sunset -Saturday AM was able to track Jupiter (off and on) till 45 minutes past sunrise – naked-eye. Thank u moon!

  2. Edward M. Boll

    Talk about fog! The first 20 minutes out with the School Bus this morning was near 0 visibility. Surprisingly, I was only a minute behind schedule after it cleared up.

  3. caralex

    Bob, do you know if birds use the Harvest full moon for migration? I suppose it makes sense that they do, but it’s amusing to think of them observing it from first quarter to full, and tweeting each other on travel plans!

    1. astrobob

      Hi Carol,
      While I don’t know for sure if they use the moon, I would doubt it since it’s a moving target. I’ve heard some birds use Earth’s magnetic field.

  4. Hey Bob,

    We plan on using your latest image of Saturn and Venus as Today’s Image on tomorrow, September 17th!!

    We proudly linked to your blog and properly credited you!

    Thanks so much and keep up the good work.


  5. Edward M. Boll

    Tomorrow is another 4 AM work day start. As I drive east, I like to look at Jupiter which is climbing nicely higher every day. And I like to glance toward the north for possible northern lights. I have not seen any in so many years, I think if I do I will stop for a few seconds to enjoy them.

  6. Sean

    hey Bob! proud to get my comment referenced in your blog! and I have been able to see Saturn nearly every evening with Venus, and got a couple of decent photos thru binos during the week, along with a couple of lousier ones with my cell phone alone. also like seeing 2 of my favorite online astronomy sites collaborating!

Comments are closed.