Nasa

Crescent Moon HDR

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2020 August 24

Made from 14 light frames by Starry Sky Stacker 1.3.1. Algorithm: Mean

Crescent Moon HDR
Image Credit & Copyright: Miguel Claro (TWANDark Sky Alqueva) (posted with permission)

Explanation: How come the crescent Moon doesn’t look like this? For one reason, because your eyes can’t simultaneously discern bright and dark regions like this. Called earthshine or the da Vinci glow, the unlit part of a crescent Moon is visible but usually hard to see because it is much dimmer than the sunlit arc. In our digital age, however, the differences in brightness can be artificially reduced. The featured image is actually a digital composite of 15 short exposures of the bright crescent, and 14 longer exposures of the dim remainder. The origin of the da Vinci glow, as explained by Leonardo da Vinci about 510 years ago, is sunlight reflected first by the Earth to the Moon, and then back from the Moon to the Earth.

Source: https://apod.nasa.gov/apod/ap200824.html

Planetary Transit Time Chart

Image by Cathy Kinnaird

Source: Channels by Type 4 – Understanding the Transit Program

Except that we don’t use the 29.5 days synodic cycle in Human Design, but the 27.3 days sidereal cycle.
See calculations here: Lunar Cycle Calculations