Daily Image

Click here or on the picture for a full size image.

The Ghost of Tycho

Submitter: Rik ter Horst
Description: About a year ago I observed the Tycho crater on the Moon under good conditions with my 40 cm telescope. At that time Tycho was located near the terminator (i.e. the border of day and night) so the central mountain was entirely hidden in the shadows. At high power I was suddenly triggered by a faint diffuse dot in the middle of the dark floor of Tycho. At first I thought of some reflections between my eye and the eyepiece. But the dot stayed fixed with respect to the crater, so I conjectured that this speck might be the central mountain, indirectly lit by the Sunlight reflected from the crater rim. I could even see it being lit from that direction.

This observation made me decide to capture it with a camera one day soon! That day was last Sunday morning, when Emil Kraaikamp and I decided to do some imaging on Jupiter. We were lucky that the Moon was in the right phase to study Tycho as well.

The top image shows Tycho as we know it, while the bottom one shows detail within the dark crater floor, including the central mountain, which is lit by the crater rim on the right!

Actually, the bottom image is just a processed version of the top one. It was made with a 40 cm telescope and a Basler Ace camera. I was happily surprised to see an exact copy of my visual observation of one year before.

In the future we will make more of these images for sure!
Copyright: Emil Kraaikamp, Rik ter Horst
  Follow us on Twitter
Please feel free to submit an image using the Submit page.