2016-07-10 - Montreal West, QC - Unknown

Two stripes speed across moon in telescope in barely a second; no trees in view. Quickly disappear.

Sudden Appearance of Stripes on the Moon On July 10, 2016 at 9:11 pm, I was taking pictures of the moon through my 6-inch Dobsonian telescope (Orion Skyquest). I was using the afocal method, putting an Olympus SZ16 camera up to the eyepiece to photograph what I saw. I was not using my moon filter to dim the brightness of the moon. (I used it later in the evening, but not at that point.) I took a series of nine photographs of the moon at that point. I had taken an earlier series before photographing stars and planets, and a later series after photographing more stars and planets. During this particular series, the striped moon appeared as number #6 of 9 photos at 21:11 and 42 seconds.

As I was setting up photo #6 in the series, I had the moon in my sights which I checked by eye. Then I put the camera up against the eyepiece and adjusted it until the moon appeared fully on the LED screen. I had my finger on the shutter button, when suddenly the top of the moon darkened as I watched. Two dark spots appeared at the top of the moon, and then streaked at high speed from the top of the moon to the bottom of the moon, not quite the diameter because it was off center. It left two shadowy stripes that appeared in less than a second. My finger was on the shutter button, I barely hesitated for a fraction of a second, and then I thought, “Branches.” And then I took the picture.

I then looked up at the sky. The moon was high above the horizon in a clear field of vision. The trees in my backyard and neighboring yards were to the far left and right. There were no branches obscuring the moon. I would know. I have taken many artistic pictures of the moon behind branches. The view was clear.

It occurred to me that a couple of my long, dark hairs floated through the open aperture of the telescope, which is like a cannon barrel, and landed on the mirror. That would have been a problem for me with subsequent photos. The best way to test the situation was to take another picture. Less than two mintues later, at 21:13, I took another picture of the moon. It was clear. When you compare the two pictures, you see that the striped moon has a dark area at the top, as if a cloud settled over it. The stripes have a peculiar jagged aspect, almost like a zipper or a series of stitches.

The diameter of the moon is 2158 miles. The stripes sped across the moon off center. My guess is that the stripes covered about 1500 miles in barely a second. Travelling at 1500 miles per second comes out to about 90,000 miles per hour.

I showed the photo to my husband, who has a PhD in statistics and is very analytical. He said, “It's branches.” When I discounted that theory, he said, “Two hairs in the aperture.” I told him the hairs quickly disappeared, and hairs do not start at the top and zip across at high speed. Then he said, half joking, “It's two spaceships flying at astronomical speed in formation.” I decided to report it.

I am enclosing photo #6 in the series, the striped moon, and photo #7, which is the picture that was taken two minutes later. A Dobsonian refractor always shows a mirrored image, so the only post-processing I did was to flip the image so that the moon appears with the lit side on the right, which is how it actually looked in the sky.

I know there is probably a logical explanation, but I can't think of one.