Record breaker: newest new Moon spotted!

By Phil Plait | April 21, 2010 7:30 am

Thierry Legault is a French amateur astronomer… and if ever the word "amateur" were misleading, it’s here. Thierry is an incredibly accomplished astronomer; his pictures have graced my blog many times in the past. Like when he caught the Shuttle and Hubble silhouetted against the Sun, or this lighthearted picture of someone painting the Sun, or the Shuttle and the space station transiting the Sun.

Come to think of it, he seems to have a fetish with the Sun. But that’s good, because he’s done it again: he’s captured a record-breaking picture of the newest new Moon!

thierrylegault_newmoon_ann

It’s very hard to see, so I bracketed it with those red lines. Thierry caught the Moon when it was as absolutely close to the Sun as it could get at the time, so in fact this is the youngest Moon it could possibly be!

So what does that mean?

moon_sun_pathHopefully this terrible diagram I slapped together may help. Picture yourself on the Earth (that should be easy) marked by the E in the drawing. Once a day it appears that the Sun (yellow circle) circles the Earth (black path). The Moon (crescent symbol) circles the Earth once per month — well, it rises and sets every night, but relative to the Sun the Moon moves slowly across the sky. The Moon’s distance to the Sun changes so that at sunset every night, the Moon is in a noticeably different part of the sky than it was the night before.

New Moon is when the Moon and Sun are as close together as they can be, and it happens once per month or so. But since the Moon’s orbit is tilted, it doesn’t always pass directly in front of the Sun (creating a solar eclipse); it misses by a bit. But still, the Moon is so close to the Sun in the sky that we’re basically seeing the half of the Moon that’s unlit (the lit half is facing away from us, toward the Sun). When it’s offset a bit from the Sun, only the barest, slimmest bit of it is lit that we can see, producing an extremely emaciated crescent.

When you go outside and first notice the crescent Moon with your eye, it’s usually been a day or two since it passed its closest point to the Sun. The crescent is thicker, making it easier to see, and it’s farther from the Sun than at the exact moment of New Moon, reducing the glare. The closer the Moon is to the Sun, the thinner the crescent and the brighter the sky, making it doubly harder to catch. In Thierry’s case, he caught it when it was only 4.6 degrees from the Sun — only about 9 times the diameter of the Moon itself!

That’s why astronomers prize seeing the thinnest possible crescent; it’s a contest, like anglers catching the biggest fish or bird watchers seeing a rare species. It shows that the person involved has used a lot of skill and experience… and clearly Thierry has those!

thierrylegault_scope_setupThis picture shows just how difficult Thierry’s setup had to be. Look how close to the Sun he was shooting! The screen blocks a lot of the glare from the sky, and the circular hole lets the ‘scope see the Moon while cutting back on glare a little more. To reduce the sky brightness further he used an infrared filter; the sky doesn’t emit as much infrared light, so it appears a little bit darker, while the Moon does reflect IR (from the Sun), making it easier to spot. He used a filter that let through light at a wavelength at 0.85 microns, just a hair outside what the human eye is sensitive to.

Of course, he couldn’t see the Moon with his eye. So he aligned the telescope with the stars the night before to get it properly tracking the sky, and then used a computer program to aim the telescope at the position of the Moon. And obviously, it worked!

This was an amazing feat. And the only way to beat it is to catch the Moon at exactly that closest solar approach when the distance is actually smaller (or, if you like, closer to the point where the two paths of objects intersects on the sky). That’ll make this observation even harder… but I suspect Thierry’s already planning his next attempt.

Comments (36)

  1. Amy F.

    The Islamic and ancient Hebrew calendars are also based on when the crescent moon is first sighted after new moon.

  2. According to your own link, the painting photo is by Laurent Laveder. Legault is mentioned.

    The moon photo is amazing.

  3. Is this really a record? According to Legault’s website, the Moon and the Sun were 4.6° apart at conjunction – but already two years ago a German amateur caught the Moon 4.58° from the Sun. This feat caused considerable interest back then and got him even an invitation to an Islamic astronomy conference, as far as I remember.

  4. JohnW

    This isn’t about vampire movies?

  5. Terrible diagram? Not at all! Your vast photoshop skills continue to amaze me! ;)

  6. ChH

    Thierry Legault is going to have to do better than that to break the record.

    Muslims occasionally see new crescent moons BEFORE the moon’s closest approach to the sun, resulting in a 31 day lunar month (such as happened in January 2000 and November 2005).

    But then, we have to take their word for it. They don’t have awesome pictures like Thierry Legault.

    On a more serious note … wouldn’t a picture of a solar eclipse taken just after half-way through totality qualify as a newer new moon than this picture?

  7. bigjohn756

    Finally, an admission by a professional astronomer that the Sun does, indeed, go around the Earth with a diagram to illustrate it. I KNEW IT ALL ALONG!!!

  8. Jeff

    Phil

    for a quick diagram, you didn’t do bad. I do them in my classes all the time and mine are only about 50% as good as that. So you are more of an artist than me, and I’m pretty sure the art part of my brain is being blocked

    and big John, you are kidding right? He is referring to the celestial sphere viewpoint with the sun orbiting the ecliptic.

  9. JohnT

    It does not count, not taken in light visible to the human eye therefor it can not bee seen. Might as well do as ChH said

  10. Kee

    I think ChH’s question should be addressed. A picture of a solar eclipse taken an instant after halfway through seems to qualify as newer than this picture. Why is that scenario not taken into account?

  11. Kevin

    Cool news. I had a share of the record back in 1989, but only for a short time. We actually used to go out and try to find the young moon.

    Ah, the good old days.

  12. Shoot. When I read the title of this blog article I thought you meant a second satellite (at a considerable distance) orbiting Earth, say a tiny captured comet or asteroid, had been spotted. That would have been amaazing.

    Which takes nothing away from Thierry’s accomplishment, Phil. That’s amazing too. Remember, the original meaning of “Amateur” is specialist. It doesn’t mean “unknowledgable rookie.” Abraham Lincoln was an “amateur” law student until he passed the bar, having had only 1 year of formal “education” and being a bookworm and self-taught. Good luck Abe even being allowed to take that test today given the current system.

  13. Plutonium being from Pluto

    … he seems to have a fetish with the Sun. But that’s good, because he’s done it again: he’s captured a record-breaking picture of the newest new Moon!

    So a photo of the Moon proves he has a fetish of the *Sun*? Er … what?!? ;-)

    Plus I agree with 4. ChH (& 7 Kee also) saying :

    “… wouldn’t a picture of a solar eclipse taken just after half-way through totality qualify as a newer new moon than this picture?”

    & one more tiny semantic nit :

    Isn’t the “newest new moon” technically the most recently discovered planetary satellite which would make the newest new moon one of Pluto’s two new natural satellites either Nix or Hydra! ;-)

    (Or did we find another newer moon around another planet since then?)

    Pedantry aside however – that’s pretty durn impressive! Well done Thierry Legault. 8)

  14. I say, it’s just plain cool. I love Thierry’s devotion and ambition; some would say he is the traditional definition of amateur.

  15. MarshallDog

    “Shoot. When I read the title of this blog article I thought you meant a second satellite (at a considerable distance) orbiting Earth, say a tiny captured comet or asteroid, had been spotted. That would have been amaazing.”

    Yeah, I thought something similar. I thought Phil meant he discovered a new moon, and when he started mentioning how close to the sun he was looking, I thought he meant around Mercury. Which would be really cool, because I keep hearing about how there’s no way Mercury could have a moon.

  16. Once again, a scientist does the job of an artist. MS Paint much, Phil? ;-)

  17. Phil is a geocentrist! ha ha

  18. KC

    Note the Hebrew calendar is not based on sightings of the crescent moon, but on the time of new moon. The Muslim calendar only allows for sighting be done with the naked eye, so this telescopic one wouldn’t count.

  19. CJSF

    Re-reading this blog post, I think Phil is saying that this is as close to the sun in the sky that the moon could be *for that lunar cycle*, not for all time.

    CJSF

  20. Thierry Legault is an amazing photographer

  21. Michel

    Very cool photo.
    His dead reckoning with his scope is pretty impressive.
    And ok, he useses the computer from the scope, but still. Impressive.

  22. Levi in NY

    EDIT: Never mind, someone already said what I tried to say here.

  23. Cool pic!

    You can do a similar trick with Venus once every 8 years. Venus passes about 8 degrees above the Sun when it is at inferior conjunction. At this time, you can glimpse Venus in the morning AND the evening of the same day! I successfully did this in 2001 but that was before I was doing serious photography of that nature. It happened again in 2009, but now I live in Tucson and the mountains don’t give nice flat horizons you need to pull it off.

  24. Alan in Upstate NY

    An amazing shot, but the term “spotted” is a misleading. To me, it implies someone saw it.

    Clear skies, Alan

  25. JupiterIsBig

    #15 Plutonium wrote
    & one more tiny semantic nit :

    Isn’t the “newest new moon” technically the most recently discovered planetary satellite which would make the newest new moon one of Pluto’s two new natural satellites either Nix or Hydra!

    (Or did we find another newer moon around another planet since then?)
    ——
    Wouldn’t that be the newest very old moon ?

  26. MadScientist

    The representation of the new moon shouldn’t be a crescent – unless it’s as viewed from a location other than earth. I’m not sure this earth-centered system is widely accepted today either. Will this diagram appear in Bad Astronomy Second Edition?

    That has me thinking – would the moon be clearer if, say, a yellow-orange filter were used to dampen that awful blue light? Substitution can always be used to fill in the blue later if you really wanted a blue sky.

  27. MadScientist

    oops … I retract the statement about the new moon crescent – but the crescent is still in the wrong apparent orientation and the Ptolemaic model is still wrong. That’ll teach me to have a closer look at the geometry before punching my keyboard.

  28. Plutonium being from Pluto

    @28. JupiterIsBig Says:

    #15 Plutonium wrote: “& one more tiny semantic nit :

    Isn’t the “newest new moon” technically the most recently discovered planetary satellite which would make the newest new moon one of Pluto’s two new natural satellites either Nix or Hydra! (Or did we find another newer moon around another planet since then?)”
    ——
    Wouldn’t that be the newest very old moon ?

    Well it would depend on what the phase was at the time! ;-)

    PS. Yeah, I do take your point – & I was being over picky there anyhow.

  29. JB of Brisbane

    At the risk of treading on someone’s copyright:

    “I saw the crescent…
    You saw the whole of the moon.”

  30. Megan

    @ 4. JohnW ….
    No, you idiot. This article is obivously NOT about sparkly vampires and shapeshifters.

    And yes, Thierry does have a fetish with the sun. ;) (Yet another amazing photograph.)

  31. just a few words to thank all of you who have written nice comments (and also to Phil!).

    Also a reply to Daniel and ChH: the New Moon being defined as the conjunction of the Moon and the Sun (same ecliptic longitude), my image and an image taken in the “middle” of a total eclipse (very easy to take if you are at the right place, I took several images of the Moon with Earthshine during the 2006 total eclipse from Egypt and it appears even on the raw images) are strictly similar on this point of view, none can be qualified as “newer” than the other. And this is the reason why I have titled my page “New Moon CRESCENT record” ;-)

    In the first version of my page, I have mentioned the angle between the Moon and the Sun as being 4.6°, actually I had rounded the value, a more accurate figure (for the ones who like precision) is 4.55° according to jpl ephemeris program. This is a little bit smaller that the German amateur Martin Elsasser 2 years ago, furthermore he took his images 5 minutes before New Moon and not at exact New Moon ;-)

    regards

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