❖ Browsing media by sekula

Moon 1 - Sept. 4, 2016

The moon, waxing crescent, in the Western sky on September 4, 2016. Photo taken shortly after sunset with a higher ISO setting.

The Moon is our natural satellite. The same side always faces the Earth, due to gravitational tidal locking. The Moon orbits the Earth every 28 days, so every night it moves 1/28th of the way further East in the sky, away from the Sun, until it cycles back 28 days later. When the Moon is on the West side of the Earth at sunset, its surface it barely lit by the Sun due to the fact that the Moon is very nearly between the Earth and the Sun. When the Moon is more in the East when the Sun sets, or in the sky during the day time, its side facing us is more completely lit, due to the fact that the Sun is more and more on the opposite side of the Earth from the Moon. When the illumination due to the Sun is increasing, this is the "Waxing" phase; when it declines 14 days into its cycle, this is the "Waning" phase.

The features of the Moon visible here (from bottom to top in the photograph) are a large, gray, smooth circular area called a "mare" (Latin for "sea"), known as the "Mare Crisium" (the "Sea of Crisis"). Mare are the result of the last bombardment of the Moon (about 1 billion years ago), when meteors pummeled its surface and the heat of impact liquified the crust, making these dark, smooth, younger-looking regions that contrast in color with the older, lighter, more cratered regions.

The small crater about midway up the right side of the Moon is the Langrenus Crater. As we get to the top of the picture, we find a more cratered surface - this is older crust on the Moon, including the Stevinus Crater.


4 years, 1 month ago

Tagged with

moon · astronomy

Collected in

Astronomy (sekula)

Report media


All rights reserved