As the Earth moves between the sun and the moon, the moon will take on a deep red shade.

A full moon moves through the shadow of the Earth during a total lunar eclipse [File: Mike Blake/Reuters]

The night sky is about to deliver a rare spectacle.

A total lunar eclipse will occur on March 13-14, 2025, and the moon will be cast in a deep, coppery-red hue. This eclipse will be observable from the Earth’s Western Hemisphere.

Here is all you need to know about the eclipse, why the moon will appear red, where you can watch it, and how rare this is.

What is a total lunar eclipse?

A lunar eclipse occurs when the Earth positions itself directly between the sun and the moon, obstructing sunlight and casting a shadow over the moon’s surface.

There are three primary types of such eclipses:

Total lunar eclipse – The moon is completely in the Earth’s shadow and takes on a reddish hue.

Partial lunar eclipse – It happens when the Earth’s shadow covers a fraction of the full moon. The shadow expands and then recedes, but never reaches the totality phase.

Penumbral lunar eclipse – A subtle phenomenon where the moon passes through the Earth’s outer shadow, known as the penumbra. The moon appears dimmer than usual.

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Why does the moon appear red?

During a total lunar eclipse, the moon turns red or orange. The only sunlight that reaches the moon has to first pass through the Earth’s atmosphere.

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There, the sunlight bumps into dust particles, water droplets and atmospheric gases. A phenomenon known as Rayleigh scattering comes into play: colours of the sunlight that are associated with longer wavelengths scatter less and are able to make it around the Earth to reach the moon, while shorter wavelength colours scatter everywhere else and never make it to the moon.

The colours in sunlight — as anyone who has seen a rainbow or observed a prism knows — range from violet (the shortest wavelength) to red (the longest wavelength).

The red light that makes it to the eclipsed moon reflects off its surface, giving the Earth’s only natural satellite that colour.

What time will the blood moon lunar eclipse occur?

This total lunar eclipse will be visible across much of the Western Hemisphere. North and South America are expected to be able to see the whole process.

Here’s a breakdown in Greenwich Mean Time:

  • Penumbral eclipse starts: 03:57 GMT (23:57 ET)
  • Partial eclipse starts: 05:09 GMT (01:09 ET)
  • Total eclipse starts: 06:26 GMT (02:26 ET)
  • Maximum eclipse (Deepest Red Color): 06:58 GMT(02:58 ET)
  • Total eclipse ends: 07:31 GMT  (03:31 ET)
  • Partial eclipse ends: 08:47 GMT (04:47 ET)
  • Penumbral eclipse ends: 09:59 GMT (05:59 ET)

The totality phase, during which the moon is entirely covered by Earth’s shadow, will last for about 65 minutes. Overall, the eclipse will span between 03:57 GMT and 09:59 GMT.

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(Al Jazeera)

Is a blood moon rare?

A total lunar eclipse is not rare, but it does not happen frequently either – there are usually a few every decade.

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The most recent blood moon occurred on November 8, 2022. The next one is expected on September 7-8, 2025, and it will be visible across Asia, Africa, Australia and parts of Europe.

What is the relevance of the total lunar eclipse?

A total lunar eclipse holds significance in various ways, ranging from scientific and astronomical importance to cultural and symbolic meanings. Some of these include:

Studying Earth’s atmosphere: Scientists can analyse atmospheric composition, pollution, and volcanic activity by examining how sunlight passes through the Earth’s atmosphere.

Exoplanet research: According to NASA, studying how light bends around the Earth during an eclipse allows astronomers to better understand how planets orbiting other stars behave when they transit in front of their suns.

It also provides an opportunity to observe and analyse the interaction between the sun, moon and the Earth.

Culturally, many ancient civilisations associated lunar eclipses with omens, deities, or supernatural occurrences. Some believed they signalled change or divine messages.

In Hindu mythology, lunar eclipses are linked to the demon Rahu, who is believed to swallow the moon. Other cultures view the eclipse as the moon being swallowed by other creatures, such as a jaguar in Mayan tradition or a dog in China.

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How to view the lunar eclipse?

Lunar eclipses are some of the most accessible celestial events to observe.

To witness one, just step outside, and look up – no telescope or special equipment is required. However, using binoculars or a small telescope can enhance the experience by revealing more details of the moon’s surface.

NASA also recommends finding a dark location as “the eclipse will be more vivid in areas away from city lights and light pollution”.

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