Tycho can exhibit a strange blurring effect around part of the outer rim. It can be seen both visually and in some high resolution images. I decided to investigate the causes of this as it is a trait shared by only a few craters and was captured in one of my higher resolution images.
The craters blurred-looking ejecta is the result of its extensive secondary cratering and ballistic sedimentation from the impact that created it. When Tycho formed, it released a massive volume of ejecta at high velocities, scattering debris far across the lunar surface. This material settled in uneven layers, creating the characteristic rays and diffuse ejecta blanket seen around the crater.
Ballistic Sedimentation: Ejecta was expelled and then settled in overlapping layers, softening the boundaries of individual fragments and creating a somewhat diffused effect that can be seen.
Optical Effects & Space Weathering: Over time, micrometeorite impacts and exposure to the harsh space environment cause gradual changes to the regolith, slightly modifying the initial contrast between bright ejecta and the darker lunar surface.
Imaging Resolution & Angle: Some photos—especially when taken under certain lighting angles—can emphasize the diffuse nature of the ejecta, making the blurring effect more pronounced.
Other craters that can show this effect are:
1. Copernicus
2. Aristarchus
3. Kepler
4. Proclus
5. Jackson (A far-side crater)
Take a look through some of your images to see if you can identify this effect.
Here is my image of Tycho taken with the 18”, to the east are two melt pond.
Jon.