seen on the moon

[deric]

Many years ago as a kid of about 10  a friend and I and my dad were on the porch looking at the moon with my 2 1/2 inch telescope. Cheap yes but you could see a lot of craters as well as the ring of Saturn and the moons of Jupiter.  

   

All of us observed what appeared to be an arch like thing protruding from about 2 o'clock on the moon's edge  . We looked at it for a few minutes I'm sure and it didn't change in form.

  If you think of the St. Louis Arch it was like that. And considering how far above the moon's edge it was and the fact you could see the legs of the arch it had to have been huge.  It was probably sticking out from the moon's edge about -if the moon was 20 mm dia. the arch would have been about 1 or 2 mm. in height.  

 My friend still occasionally talk about this so it's not like it's only me who can talk about it.  At the time dad didn't offer any comment on what it was.  I knew about cleaning the lenses so it wasn't something like that.  I've posted this or emailed it to different university folks but got little response.  My best guess is it might have been a plume of dust from a meteor but that almost seems like it was too large a structure for that.  

[michael.h.f.wilkinson]

This almost sounds like the Sinus Iridium (Bay of Rainbows, see below), or some half illuminated crater on the terminator

[Stu]

I'm sure that's the most likely explanation, anything else would have got a lot more attention I'm sure.

This image shows it as an arch, with shadow underneath, much as described.

Stu

[Alien 13]

My thoughts too.

Alan

[Grotemobile]

This almost sounds like the Sinus Iridium (Bay of Rainbows, see below), or some half illuminated crater on the terminator

What were you using to take that.

Looks very close.Great pict.

Steve

[michael.h.f.wilkinson]

What were you using to take that.

Looks very close.Great pict.

Steve

Not mine, alas.

[Laurie61]

I wonder if this was a line of sight effect, as the bridge was on the edge/limb, if an appropriately shaped group of stars were close to the moon it might look as though they formed part of a moon structure ? the Moon moves at a different rate to the star field but in a small scope at low mag the effect could last for several minuets.    

[MAN or ASTROMAN]

Some marvelous images there.Thanks for sharing to all concerned.

[Ace_Dante_Sparda]

Yeah I got that recently 2-3 years ago on my 'new' Celestron NexStar 4se.