Planet triangle graces the western twilit sky

By Phil Plait | August 6, 2010 2:30 pm

If you look west after sunset, you’ll probably spot the fourth brightest object in the sky*: Venus.

skytel_planetmapBut as I looked west recently, I noticed two bright(ish) objects just above it. It didn’t take me long to figure out that they were the planets Saturn and Mars. Both looked red due to their low altitude above the horizon, and both were about the same brightness, so I wasn’t sure which was which. Happily, Sky and Telescope has a map (shown here) and a write-up of what’s what.

Interestingly, although Saturn is far larger than Mars, it’s much farther away, so they appear to be about the same brightness in the sky. All three of these planets will change their positions noticeably over the next few weeks, so you can watch as the dance of gravity morphs their configuration. Also, on August 12 and 13, the crescent Moon will slide past the trio, which should make for a very nice photo opportunity.

Not only that, but if you stay up late, you can catch the Perseid meteor shower as well. I’ll have more about that later. But until then, even people who go to bed early can spot and appreciate the view to the west.

* The first three being the Sun, the Moon, and the International Space Station.


Comments (22)

  1. It’s always nice when the directions read “after sunset,” that guy on public access was always saying things like “at 4 am you’ll be able to see [blank],” which if I’m still up at 4 am, I am waaaay to drunk to look for whatever he was talking about. I had heard somewhere that this month is the closest Mars will be to the earth for a very long while, I was wondering if that was the case.

  2. I hear that Mars will be as big as the moon soon.


    @Rhacodactylus, it happens every 780 days that Earth and Mars pass (synodic period). Because that’s not really lined up with viewing though, the best viewing comes around every 15-17 years. This graphic may help: But it’s absolutely not this:

  3. #1: Are you talking about Jack Horkheimer? That’s the show that introduced me to Isao Tomita. :)

  4. I have posted several pictures of the planets (the first one in conjunction with the annual Mars Hoax post to show that Mars is REALLY small, like a dot) for a couple of weeks now. Unfortunately, I have been fighting clouds and travel in my efforts to document their movements.

    However, I have gotten a picture from Tucson on July 22nd (, the Hume Observatory on July 29th, (, and San Diego on both August 1st ( and August 2nd ( I was hoping to get some in Boulder this week, but it was cloudy ever night…and it’s not looking so hot now that I am back in Tucson for the next few days.

  5. Here is the situation as it played out in Germany two hours ago – with the flat evening ecliptic at 52¬įN and some cloud banks and trees quite a challenge …

  6. MadScientist

    Is Mercury not too far away as well (or is it on the other side of the sun)?

  7. The incredibly vanishing Lunar water post?

  8. Josie

    Where can I go to learn how to find these objects? I’m pretty good at finding the Sun and the Moon :) and sometimes I can pick out Venus (I think), but I would have no idea how to find the ISS or any other specific object.

    I know I could JFGI but I would prefer a little help from people who make sky gazing their hobby :)

  9. Arrrgh! I hate the weather this time of year. We’ve been socked in with fog and overcast for a solid week:

  10. #1 Rhacodactylus:
    The thing about Mars being its closest for a long time is a bit of misinformation which goes around the web every August. The record closest approach occurred in August 2003.

    See www dot spaceandsanity dot com/miscmadpage8.html

  11. The sight of the crescent moon, Venus, Saturn, Mars, et alia, last month literally knocked me off my feet (that case of Guinness contributed a wee bit). This month is almost as good.

    I spied the twilight sky
    And all I could do was sigh…

  12. Conrad

    Wait a sec, isn’t Venus the third brightest object in the sky? Unless you count iridium flares, gamma ray bursts, and other phenomena the next brightest static objects after Venus should be just the moon and the sun.


    @ Josie (#8):

    Where can I go to learn how to find these objects? I’m pretty good at finding the Sun and the Moon and sometimes I can pick out Venus (I think), but I would have no idea how to find the ISS or any other specific object.

    I can recommend these links:

    * Your Sky
    * Heavens Above
    * Satellite Flybys

  14. Lonnie

    I brought out the telescope for the neighbor kids to take a look at the trifecta. Lots of “Whoa”s and “Wow”s. Especially for Saturn. Impressed a few parents too. I would like to think I sparked a neuron or two in a future astronomer.

  15. Visibility has been hit and miss here, but I’ve been posting photos since last Thursday. I’m working on tonight’s post right now. Sunday night will be the closest configuration of the three, but the thin crescent Moon will join them on the 12th and 13th. Check out Jack Horkheimer’s excellent stuff on this, too!

    One fascinating thing: even taking photos with my little Nikon Coolpix L4, I’m still able to capture some of the brighter background stars. And it’s fascinating to see them thunder by and change their position with respect to the planets from night to night. I’ll throw up links on a later comment, but you can just click on my name to get to my blog and scroll down past the Carrot Cake recipe and whatnot to the “Planetary triangle” posts.

  16. Grimbold

    “Wait a sec, isn‚Äôt Venus the third brightest object in the sky?”

    I think the International Space Station is now marginally brighter.

  17. Maria

    Ahh, that makes sense. I was about to ask as well. I also thought Venus was the third brightest object. Man, first you people turn Pluto into a pumpkin and now you mess with the light of Venus. ūüėõ

    I think I saw the space station go by a few nights ago. Something about as bright or even brighter then Venus and moving at a good clip. That or a satellite. Nifty to see.

  18. OK, just finished up my post with today’s pictures. I included links to all of my previous “Planetary triangle” posts, including the introductiory one with the links to the Jack Horkheimer videos.

  19. zak

    bro thanks for that i am a neophyte and couldnt figure it out myself. wanted to know what i was looking at tonight. nice!!!

  20. hale-bopp @4, your pictures are beautiful! (Though I had to delete a stray parenthesis that got caught in the URLs.) I especially love the cloudy twilight one from San Diego!

  21. Robert Carnegie

    Doesn’t this stuff cause earthquakes, or something? :-)

    All those planets pulling on Earth from the same direction, bound to do some damage…

  22. Josie

    Thank you Ivan :) now to find a dark(ish) corner of San Diego County….


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