Tag Archive


amateur astronomy awk bash be b[e] supergiant cartoon conference convert evolved star exoplanet fedora figaro fits fun galaxy history iraf jupiter latex linux lmc machine learning massive star matplotlib meteor mypaper paper peblo photometry planet pro-am pyraf python scisoft skinakas observatory small magellanic cloud smc spectroscopy starlink talk theli ubuntu university of crete video x-ray

Moon (Lunar) phases

Just a quick note for moon (or lunar) phases.

Moon (Lunar) Phase Diagram

From Wikipedia / Lunar Phases (moon phases).

Phase Northern Hemisphere Southern Hemisphere Visibility
New moon Not visible, traditionally Moon’s first visible crescent after sunset
Waxing crescent moon . Right 1-49% visible Left 1-49% visible afternoon and post-dusk
First quarter moon Right 50% visible Left 50% visible afternoon and early night
Waxing gibbous moon Right 51-99% visible Left 51-99% visible afternoon and most of night
Full moon Fully visible Fully visible sunset to sunrise (all night)
Waning gibbous moon Left 51-99% visible Right 51-99% visible most of night and morning
Last quarter moon Left 50% visible Right 50% visible late night and morning
Waning crescent moon Left 1-49% visible Right 1-49% visible pre-dawn and morning
Dark moon Not visible, traditionally Moon’s last visible crescent before sunrise

For the intemediate lunar phases keep in mind that:

crescent : less than half illuminated

gibbous : more than half illuminated

waxing : becoming more luminous

waning : becoming less luminous

So, by combining the terms you can figure out where the moon lies in its orbit and what the phase will be:

> after new moon, the moon becomes more luminous than before, but still less than half in total = waxing crescent

> after first quarter, the moon contimues to raise its luminosity but more than half = waxing gibbous

> after full moon, luminosity drops but still more than half is illuminated = waning gibbous

> after last quarter, luminosity drops even more (towards full moon) but now the total illuminated area is less than half = waning crescent

Moon phase calenders:

1. www.moonconnection.com – current phase moon & calendar

2. U.S. Naval Observatory – moon phase images

3. U.S. Naval Oceanography portal – phases of the moon