{"id":52443,"date":"2023-12-05T13:15:22","date_gmt":"2023-12-05T13:15:22","guid":{"rendered":"http:\/\/51406b4f-20a2-4912-9037-3eafea2cbbee"},"modified":"2023-12-05T13:32:36","modified_gmt":"2023-12-05T13:32:36","slug":"complete-guide-to-the-phases-of-the-moon","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/complete-guide-to-the-phases-of-the-moon\/","title":{"rendered":"Complete guide to the phases of the Moon"},"content":{"rendered":"

A guide to the phases of the Moon, and why its appearance changes night after night from crescent to gibbous and back again. <\/p>

By Jane Green\n <\/p>

Published: Tuesday, 05 December 2023 at 13:15 PM<\/p>

\n\n

The phases of the Moon are something you’ve noticed from time to time in the night sky, but perhaps never really thought about.<\/p>

What causes the phases of the Moon is really nothing more than the Moon’s orbit around Earth, Earth’s orbit around the Sun, and how this all appears from our pespective.<\/p>

The Moon may appear to change shape, but the bright surface you see and the ‘moonlight’ that reaches Earth is sunlight reflecting off the lunar surface.<\/p>

As the Moon orbits our planet, its varying position means the Sun lights up different regions, creating the illusion that the Moon is changing shape over time.<\/p>

Keep up with the phases of the Moon by signing up to receive the BBC Sky at Night Magazine e-newsletter<\/a> every week and downloading our 2024 lunar phases poster (PDF)<\/a><\/em><\/strong>.<\/p>

The phases of the Moon. The inner circle shows what the Moon looks like seen from above its north pole, while the outer circle shows the phase we see from Earth at that time. Credit: BBC Sky at Night Magazine<\/figcaption><\/figure>

Observing the phases of the Moon<\/strong><\/h2>

The best way of getting to know the phases of the Moon is to go out on a clear night when the Moon is in the sky and observe it.<\/p>

For more on this, read our guide on how to observe the Moon<\/a>.<\/p>

The Moon lies on average 384,400km from Earth, it\u2019s stunning to the naked eye and through binoculars<\/a> or a small telescope.<\/p>

It’s also a great target to photograph. Read our guide on how to photograph the Moon<\/a> or our beginners’ guide to astrophotography<\/a>.<\/p>

The Moon’s journey around Earth<\/strong><\/h2>
\"Moon
Moon phases in the southern hemisphere Luis Rojas M, Santiago, Chile, 13 October \u2013 17 October 2018. Equipment: Canon EOS Rebel T6i, Explore Scientific 102mm ED refractor, iOptron iEQ30 Pro mount.<\/figcaption><\/figure>

The Moon seems serene but it is hurtling eastward travelling at 3,682 km\/h.<\/p>

Since its almost circular orbit is tipped just 5\u00b0 relative to Earth\u2019s, it more or less follows the ecliptic<\/a> (the Sun\u2019s apparent path) across the sky.<\/p>

You may have noticed that the Moon always keeps the same face turned towards us<\/a>.<\/p>

This is because it rotates once on its axis in exactly the same time it takes to orbit Earth \u2013 27 days and seven hours.<\/p>

This synchronisation is called tidal locking and is a result of Earth\u2019s gravitational effect on the young Moon when it was forming.<\/p>

\"The
The phases of the Moon. Credit: Yaorusheng \/ Getty Images<\/figcaption><\/figure>

As a result, we don’t see the far side of the Moon<\/a>. But we also don’t only see 50% of the Moon, either. <\/p>

We get to peak ’round the corner’ a bit every now and then during a phenomenon known as lunar libration<\/a>.<\/p>

During its elliptical orbit around Earth, the Moon moves through \u2018phases\u2019.<\/p>

This is the term we use to describe how much of the lunar disc appears illuminated as seen from Earth.<\/p>

This elliptical orbit, combined with the phases is also what leads to the appearance of a so-called supermoon<\/a>.<\/p>

\"Four
Four Supermoons of 2023 captured by Soumyadeep Mukherjee, Kolkata, India, July-September 2023. Equipment: Nikon D5600, Sigma 150-600c, Benro Tripod<\/figcaption><\/figure>

In fact, the Moon is always half lit, we just don\u2019t see it that way. Which ever of the Moon phases we\u2019re seeing, the opposite phase is happening on the far side of the Moon.<\/p>

And while we only ever see one terminator<\/a> (the name given to the dividing line between the light and dark parts of the lunar surface) sweeping right to left across the lunar disc at any time, there are actually two of them circumnavigating the Moon exactly 180\u00b0 apart.<\/p>

There’s the morning terminator (ushering in the lunar day) and the evening terminator (bringing the night behind it).<\/p>

So sorry, Pink Floyd, there is no permanently dark side of the Moon.<\/p>

\"The
The far side of the Moon, as seen by the Lunar Reconnaissance Orbiter. Credit: Credit: NASA\/Goddard\/Arizona State University<\/figcaption><\/figure>

Phases of the Moon at a glance<\/strong><\/h2>

In the phases of the Moon, ‘waxing’ refers to the journey from new Moon to full Moon, as the Moon appears to gain more of its sunlight section every night.<\/p>

‘Waning’ refers to the period from full Moon back to new Moon, as the Moon appears to lose more of its sunlit section every night.<\/p>

The phases of the Moon are as follows<\/p>