Go look at the Moon tonight!

By Phil Plait | September 18, 2010 8:00 am

iotmnlogoTonight is the first annual International Observe the Moon Night, an effort spearheaded by folks at NASA’s Goddard Space Flight Center to get people outside and looking at the sky.

This is a pretty neat idea; the Moon is big and easy to spot, and really cool through even a small telescope. GSFC has partnered with hundreds of groups to set up observing sessions all over the planet, and there’s probably one near you.

They picked a good night: the Moon will be waxing gibbous tonight, meaning it’s halfway between first quarter and full. It’s already up before the Sun sets, so it’s easily visible even during the early evening, and you don’t have to stay up late to see it. There will still be crater shadows, too (at full Moon, the Sun shines straight down on the Moon from our view and you can’t see shadows, making craters difficult to spot).

So go outside and take a look! And even though you won’t be able to see it, remember that we have a space probe orbiting the Moon right now, just starting up its science mission. There’s still a lot to learn about our nearest cosmic neighbor.


Comments (50)

  1. Messier Tidy Upper

    Tonight is the first annual International Observe the Moon Night …They picked a good night: the Moon will be waxing gibbous tonight

    All these nights in a row. Its amazing the number of people who forget the Moon is also visible in the daytime.. 😉

    Another thing to recall here is that binoculars are good for gazing at our Moon too.

    Plus, being a bit silly here, but ‘Observe the Moon Night’? Observe which moon of which planet? Hey, they’re not specifying! 😉

  2. Marge

    How about “GO BACK TO THE MOON!” Enough said!

  3. brett

    I think this is awesome, but one thing to nit-pick – why not choose a full moon to observe? I mean, if we’re going to internatioinally observe the moon, we may as well observe all of the near side instead of just some of it. I’ll observe, but then I’ll do it again in a week for full satisfaction.

  4. Bad Albert

    Here’s my local weather forecast:
    Tonight: Cloudy periods. Becoming cloudy near midnight then rain. Low 13C.

    Guess I’ll miss all the fun.

  5. Bad Albert

    Brett said:
    “why not choose a full moon to observe? I mean, if we’re going to internatioinally observe the moon, we may as well observe all of the near side instead of just some of it.”

    As BA said, it’s better before or after the full moon. You need to get the sun at an angle to create shadows. Also, the brightness at full makes it very hard on the eyes. Tonight’s phase will have a much lower contrast making it easier to pick out details.

  6. Dan I.

    @ 3. brett

    Like Phil says in the post, with the Moon at waxing gibbous you get shadows on the craters which makes them easier to spot.

    Observing during full is always good too, but you lose a lot of the depth perspective because of the lack of shadows.

  7. Kris

    “why not choose a full moon to observe?”

    Because it’s much cooler if you can see the terrain relief (craters, mountains, and stuff) and that happens only in places where the features cast long shadows — i.e. near the terminator (the day/night boundary). Away from the terminator you still can see the features of course, but they just look flat. At full moon, you can’t see the terminator, so all of the moon looks flat and boring.

    If you get any lunar atlas (either book of software), each listed feature is accompanied by information what is the best time for observing, i.e. “2 days after new moon”, or “7 days before full moon”. Its given so that the location of terminator with respect to the feature gives you optimum lighting conditions for a given feature. So, for example, the central peak of the crater is illuminated, while the crater floor is in the dark. If all of the crater is illuminated, the central peak is not so spectacularly visible.

  8. shawmutt

    Just want to say, thanks Phil, you really got me into watching the sky. I’m fortunate enough to live in the sticks so all I have to do is go out on my back porch. I’ve been using my binoculars, and they have been working great. Realizing that the specks around a bright star I was looking at was actually Jupiter and four of her moons really hooked me.

    I have a planisphere, a red flashlight, and a Nightwatch book coming soon in the mail. Hopefully I’ll learn enough in the coming years to teach my kids about the sky.

    Keep up the good work, and I’ll be checking out the moon tonight for sure!

  9. I am gonna miss the moon tonight unless it stops raining so here is a picture I took the other night. it looks a lot better big.
    moon n clouds

  10. Jennifer

    Weather permitting, I’ll go out. Sometimes my neighbors are out too, so I can promote astronomy with my ‘scope.

  11. David C

    “the moon is big and easy to spot”… it just doesn’t get any better than this :)

  12. Daniel J. Andrews

    Last week my nephew’s grade 3 class had a “sketch the night sky” homework assignment. We used the Stellarium program to get a ‘bird’s eye’ view, and then went outside and located Jupiter and the moon. We used my 80mm Swarovski (terrestrial) spotting scope to view the moon and Jupiter. At 60x we saw one distinct band and hints of other markings on Jupiter as well as the four moons. We had a great time, and he was the only one in his class to actually see Jupiter. This was a great homework assignment…and timely…it’s been cloudy ever since.

  13. QuietDesperation

    How about “GO BACK TO THE MOON!” Enough said!

    OK. Shall we do that before or after the economy finally craters? D’oh! Moon. Craters. See what I did there? 😛

    I really should get back into actual observing. I can afford about any scope Meade or Celestron makes at this point in my life. I’d like to hook up a CCD and a computer to do time exposures and image stacking and whatnot, but I just don’t have the oopmh to get going on it. :(

  14. Kylie

    Ahaha. It was a pleasant surprise to discover that one of two happening in my State is actually taking place at my school. Definitely going!

  15. Qwert

    Just a reminder, both Jupiter AND Uranus are nearing closest approach this weekend, and are close enough together that the 5x lens on my 5′ scope could see both in the same field. Considering light pollution, this is one of the best chances to find Uranus since Jupiter is so easy to spot. Heck I think you can tell Jupiter is round with the naked eye, though that may just be an illusion.

    So cool seeing that tiny star and realizing it’s bright emerald green and actually a planet you can’t see with the naked eye.

    As for sky maps, Google Sky Maps on my cellphone has been awesome.

  16. Aargh! We run a small observatory and planetarium. This would have been perfect! But I need at least 2 months lead time for publicity. I found out about it today.

    It’d be a real service if someone (365 Days, perhaps?) could publish a list of these national events. Or is there one I just don’t know about? I’m planning our 2011 calendar now.

  17. chris

    “Go look at the Moon tonight!”

    ok, so i did. i haven’t got a telescope or even binoculars so i took some shots at full zoom on my camera.
    this was the best of the bunch, even if it is a little over exposed – http://i54.tinypic.com/9jgetz.jpg – you can really see some detail on that big crater top left!

    this one’s out of focus but i accidentally caught some kind of moonbow (it’s so intense!) that i couldn’t get again – http://i51.tinypic.com/1giyro.jpg

    thanks for making me pull a pullover on and dig my tripod out from under the bed phil, i really enjoyed that 😀

  18. Gary

    OK. You make the clouds go away.

  19. josie

    After we look at the gibbous moon tonight for its own sake we can gander (pun intended) at the full moon in a few days and see if we can spot any migrating birds in silhouette :)

  20. And don’t forget:


    Moon Zoo set an original goal of categorizing 20000 images over the weekend to commemorate this, and after reaching that number in just a few hours they upped it to 40000 and now 60000. I’ve done a few dozen myself.

  21. We’re going to be socked in with clouds tonight, but I did get out last night and imaged the moon:

    Moon  9/18/10

  22. Gary

    As an only occasional moon watcher but general science groupie: what probe is currently orbiting the moon and what science is it going to do?

  23. @brett: Not only is a completely full moon boring due to a lack of contrast, it also rises later which might keep some folks from staying out late enough to view it.

    Not to mention a full moon is blinding (well, not literally) to look at through a telescope.

    Weather not cooperating here tonight, but out club had a session with what seemed like about 500 1st-5th grade scouts last night, and they were thrilled with the experience.

  24. DLC

    “We choose to go to the moon, and do these other things, not because they are easy, but because they are hard! ” — John F. Kennedy, President of the United States.

  25. Kevin

    I participated in the event personally, but my astronomy club must have had better things to do, because when I talked to the President of the club this afternoon he had never even heard of this.

    My astronomy club sucks.

  26. Adam

    I wish I could Phil but I can’t!! It’s storming!

  27. Jason

    @21 zAmboni Thats a great picture.. Better than what I managed to get tonight

    EXIF info
    Exposure 0.02 sec (1/50)
    Aperture f/8.0
    Focal Length 300 mm
    ISO Speed 100

  28. Wayne on the plains

    I had an alumni picnic tonight, so of course I brought my telescope and let everyone take a look after we ate.

  29. shawmutt

    Pretty moon, wish I had a better camera to get pics.

  30. Waydude

    Done! and checked out Jupiter too whilst I was at it.

  31. squirrelelite

    I noticed ABC showed a shot of the moon behind the Masked Rider statue at Texas Tech during the game tonight. But, they didn’t mention the International Observe The Moon event.

  32. kurt_eh


    Lousy Calgary weather. Seems like whenever I remember there’s something like this, or meteor showers, etc; we get overcast skies.

  33. Melanie

    Was just out. And with my crappy binoculars saw Jupiter and the 3 moons (thanks for tweet about that,btw. who says twitter is all about self indulgent narcissism?). I couldn’t see Uranus but given that I live in Vegas, light pollution makes seeing faint stars/planets really difficult.

  34. I had a good night looking at the moon, but only managed a few pics before the camera died.

    My flicker has them all.


  35. Derecho64

    Dragged out the telescope too – I love the partly-full moon. The shadows and contrast make for some really spectacular viewing. I liked that Sinus Iridum was at the edge of the terminator, and the ejecta rays from Tycho were nicely prominent. Got a good view of Jupiter and seeing Uranus in the same field of view was awesome. I knew they were close together, but not that close. I was reminded of Galileo’s unknowing view of Neptune when he was observing Jupiter back in 1612 – 234 years before it was actually discovered.

  36. Tim

    Many of us on nightskiesnetwork.com were setup to broadcast from our telescopes . The idea was to broadcast live video of the moon from all the time zones around the world in a 24 hour period. The broadcasters could use voice but the viewers had to type in thier requests on what objects they wanted to see next. Overall it worked out pretty well but alot of us were clouded out. You can find us broadcasting at almost any given time . Weather permitting.

  37. Tribeca Mike

    Love the readers’ photos! And can’t wait for the night of the 22nd, when Jupiter will be dangling beneath the full moon as if it was attached to a lunar watch fob.

  38. Blake P

    I went up the Von Braun Astronomical Society last night and looked at the moon using their 16 inch telescope and a planetarium show on their Saturn V shipping container dome.

  39. Menyambal

    I dusted off a pair of binoculars and went out in the yard to look at the magnified moon for the first time in years. Then I had to wait an hour for it to get to a place where I could prop the binoculars up against a building to reduce the shaking, and that didn’t help enough. And they were only like 8-power–I feel old, now.

    The moon was lovely, though. One crater was just perfectly on the terminator, so I could see shadow in it and the far rim lit up–a good time to view, indeed.

    Thanks, Phil. For the view of the moon, I mean, not for making me feel like a shaky old man–i thank my dad for that.

  40. Russ

    It’s good seeing SOME interest in lunar exploration. I have many books & images of the lunar orbiter series. And the ‘the little-blue-marble’ images. Isn’t the http://lroc.sese.asu.edu/news/uploads/E136013771_thumb1.png image available in color..? It was back then – the ’60s..

    I was 15 when JFK initiated Apollo.. To have lived through that era.. and watched it ALL..!! I do NOT recall NASA or any of the space program being referred to as ‘nerdy’. The American public was very.. very interested & watched plenty..!! The newspapers, magazines.. TV MASS MEDIA.. which we had then – what a different world..!!

    Today, people have been dumbed-down. To think.. that landing on the moon was.. faked..? I have seen how the young ones today just can’t understand HOW the USA could have possibly visited the moon… WAAAAY back then..!!! And, that isn’t the end of it – lol, tell them we actually could drive around on the moon..!!!

    Also, how many people do not know that we had a large, very spacious SPACE STATION.. way back in 1973..!! About 12,000 cu/ft.. on 3 floors..!! 100 tons – hefted into orbit.. in one shot – via the Saturn V. It was grossly neglected. Purposely.

    After JFK, RFK, & MLK were murdered, and Nixon got in.. that was the beginning of the end of manned spaceflight. It has been steadily down hill since. All of science.. steadily downward trending. Look at us now..!! The end of the shuttle. (it too was cheapened..!!) – Hubble.. no more repairs. The ISS.. we won’t be able to visit – unless we PAY some other country..!! And.. it seems destined for the ocean too.

    There has been a stealthy war against all the is science & modern in America. And now it seems that other parts of the world are getting short funded for scientific projects also. Just as Carl Sagan feared in his book: ‘The Demon Haunted World’… And just as it happened across the world’s history.. another.. a.. ‘new’ DARK-AGE is upon us..!!! The dark-agers have again.. destroyed.. trashed.. ruined our GREATEST achievements.. look around. Look at Cape Kennedy (Canaveral) and look at the Shuttle.. even the donated money to care for and maintain the duplicate SKYLAB.. was wasted – the people that were supposed to oversee that.. it is rotting away.. rusting out. And, you should know, NASA built 2 Skylab’s. Both were ‘space worthy’.. and now…??

    Remember the Superconducting Super-Collider..? Even Arecibo has been threatened. No matter what ANYONE says.. just look at how far we have fallen..

    There is no ‘reason’ – it’s impossible for ANY country to have ‘just let it slide’.. THINK..!! Look at history. Search the internet – check out what these dark-agers are up to…!!!!!!!!!!

  41. Paul A.

    How did they pick the date? And do they intend September 18 to always be Observe the Moon Night?


    Can someone please tell what the format this box uses to display numbers is called?
    1 2 0 are about half sized, the rest are full size but 3 4 5 7 9 are dropped below the text baseline. Some of my magazines seem to use this format to make dates and figures less imposing when mixed with the text.

  42. Crux Australis

    @ Daniel J. Andrews (12): I really, really wish more parents were like you.

  43. Messier Tidy Upper

    Thanks all for sharing your photos etc .. here – some nice ones . :-)

    @15. Qwert Says:

    Just a reminder, both Jupiter AND Uranus are nearing closest approach this weekend, and are close enough together that the 5x lens on my 5′ scope could see both in the same field. Considering light pollution, this is one of the best chances to find Uranus since Jupiter is so easy to spot. Heck I think you can tell Jupiter is round with the naked eye, though that may just be an illusion.

    Yeah, sadly, that would have to be an illusion. The only planet that can be seen as rounded with the unaided eye is Venus which a few people with exceptional eyesight can apparently see the phases of.

    So cool seeing that tiny star and realizing it’s bright emerald green and actually a planet you can’t see with the naked eye.

    Umm .. sorry to be pedantic here but Ouranos *can* actually be seen with the unaided eye although its very faint and hard to detect. You need a dark sky and keen eyes but it can be done. Now if it had been Neptune you were talking about there ..

    Still I agree with the sentiment. Well said. :-)

    @13. QuietDesperation Says:

    “How about “GO BACK TO THE MOON!” Enough said!”
    OK. Shall we do that before or after the economy finally craters? ..

    Before – & then it may mean the economy doesn’t crater. 😉

    Seriously, a US Lunar return would be an investment with many returns not least in national confidence and spirit. We should do this within a decade. No later.

  44. brett

    @5,6,7,23, maybe others…

    First, sarcasm. I agree that the terminus gives a much more spectacular view of the moon. Second, I’d argue that it is “International blah blah” not “Amateur Astronomer blah.” The goal is to go outside and look up and see the moon in all its glory and be amazed at the splendor of the heavens, and maybe take an interest in space science. Not grab your gear and do a thorough study of the moonscape. So, without gear, a full moon appeals to more people, especially since probably less than 1% of the earth’s population even has a telescope. I’m just saying. It was all meant in jest – I guess that didn’t come across.

    And, for the brightness – if you can afford a telescope to observe the moon, you can afford a filter too. I need one when it’s a waxing gibbous just as much as when it’s full.

  45. Tribeca Mike

    Apropos of nothing, I waxed a gibbon once. They don’t allow me into that safari park anymore.

  46. vdalson

    you shouldn’t have done that. The world is not yet ready to fully appreciate the power of our mother Luna. As the children of the moon, we will be the ones to ascend to a better place while the rest of you will merely gaze with your unworthy eyes.

    Our ascension draws nigh. Can you feel it?

  47. Tim

    You would’nt be one of those people from California that was missing?

  48. Nigel Depledge

    @ Qwert (15) –

    I spy a bit of a Spinal Tap moment there.

    I assume when you said:

    . . . the 5x lens on my 5′ scope . . .

    that you have a 5″ scope, right?

    Or do you really have a 60-inch scope in your light-polluted backyard? 😀

  49. Nigel Depledge

    Now, onto the topic of the post…

    I didn’t actually find out about this until a couple of days afterwards (yes, I don’t visit this blog every single day, especially at weekends). So, maybe they need a bit more widespread publicity (and a lot more advance notice!) next year.

    Also, it was cloudy here anyway (it had been for several days, and there was patchy rain, which might have put me off).

    But who came up with their abbreviation?? InOMN? Really?

    Surely, if they had called it “Observe the Moon Night, International” they could simply call the event OMNI, which would be much more fun and catchy!

  50. tam

    i never use my small 80mm telescope since lastyear,now i got 60×60 spottingscope,im going to use it on saturn,wondering its going gud or useless,..but it start to rain every night,..looks lyke the weather is much useless than my spottingscope itself.


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