If you are awake before sunrise on Friday, 28 August, there is a good reason to look west.

Johannesburg will see a deep partial lunar eclipse, with Earth’s shadow moving across most of the Moon before it disappears below the horizon. NASA lists the event as a partial lunar eclipse with a magnitude of 0.930, making it particularly deep.

And the most dramatic part happens just as Joburg is waking up.

The Moon Will Be Almost in Shadow

A lunar eclipse happens when the full Moon passes through Earth’s shadow.

This time, the alignment is not quite enough for the entire Moon to enter the darkest part of that shadow so that a small portion will remain outside it.

The shadowed section may appear coppery, orange or reddish.

That colour comes from sunlight filtering through Earth’s atmosphere before reaching the Moon. Blue light scatters more easily, while more of the red and orange wavelengths continue through to the lunar surface.

It is essentially the same physics that gives us red sunsets.

When to Look

The eclipse begins subtly at 03:23, when the Moon enters Earth’s lighter outer shadow.

The change becomes much easier to see once the partial phase begins at 04:33.

For Johannesburg:

• 03:23: Penumbral eclipse begins
• 04:33: Partial eclipse begins
• 06:12: Maximum visible eclipse
• 06:26: Moonset

By 06:12, the Moon will be only about 2.4 degrees above the western horizon.

That makes your viewing spot surprisingly important.

Find a Clear View to the West

A garden surrounded by high walls or a balcony facing the wrong direction may completely hide the best part.

For the maximum eclipse, find somewhere with a clear, low view towards the west, without buildings, trees or hills blocking the horizon.

The Moon sets only about 14 minutes after the local maximum, so the final part of Joburg’s view will be brief.

No Special Glasses Needed

Unlike a solar eclipse, a lunar eclipse is safe to watch directly.

You do not need protective eclipse glasses.

Binoculars can make the colour and the edge of Earth’s shadow easier to see, but your eyes are enough to watch it happen. NASA notes that lunar eclipses are visible wherever the Moon is above the horizon at the time.

The Bottom Line

If an early alarm doesn't offend you too much, aim to be outside around 05:45 on Friday morning with a clear view west.

By 06:12, most of the Moon will be deep inside Earth’s shadow.

Then, just minutes later, it will be gone below the horizon.