Stargazers are in for a treat today, as a rare ‘hybrid’ solar eclipse is set to plunge parts of the world into total darkness.
This type of astronomical event – where the moon blocks out a different proportion of the sun in different parts of the world – only occurs once every 10 years.
In some places including Western Australia, viewers will experience a ‘total’ solar eclipse, where the face of the sun is completely blocked by the moon.
But in others, an ‘annular’ solar eclipse will be visible, where the moon appears slightly smaller than the sun, leaving a ring of light around its silhouette.
According to Royal Observatory Greenwich, the event will only be visible from parts of the equator and southern hemisphere.
Those in Western Australia and Southeast Asia will be able to catch it at around 11.30am local time.
The curvature of the Earth sometimes means that the moon will be close enough to our planet during part of the eclipse to cover the whole of the sun, but too far away to do so during another part. Different parts of the world then see a total or annular eclipse
Shaded area marks the moon’s shadow moving over the Earth on Thursday; people in this area will only see a partial eclipse unless they’re in the path traversed by the black dot right in the centre – in this case they’ll see a total or annular solar eclipse
But for those in other parts of Australia and the rest of the world who want to witness the total solar eclipse, NASA is putting on a livestream from Perth Observatory in Western Australia.
This will start at 12.30pm local time and viewers will have the chance to ask NASA scientists questions about the phenomenon.
The last time a hybrid solar eclipse occurred was way back in November 2013, plunging parts of Africa, Europe and America into darkness.
And keen astronomers certainly won’t want to miss this week’s event, as the next one isn’t due until November 2031.
A solar eclipse occurs in the daytime at new moon – when the moon is between Earth and the sun – and blocks out some or all of its light.
Because the moon ‘wobbles’ up and down, a new moon can happen with it blocking all the sun (total solar eclipse) or partially blocking the sun, so it appears to have a ‘bite’ taken out of it (partial solar eclipse).
The more of the sun is obstructed, the darker it will be when the eclipse occurs.
A hybrid solar eclipse is a combination of a total and an annular solar eclipse, but it’s preceded by a partial solar eclipse as the moon moves into position.
Dr Greg Brown, astronomer at the Royal Observatory Greenwich, told MailOnline: ‘This eclipse is only visible from Australia, East Timor, Indonesia, the southern Indian Ocean and western Pacific Ocean, while the connected partial eclipse will also be visible to a few surrounding regions.’
Area indicated by the blue lines on this map is the total area that will be traversed by the moon’s shadow on Thursday. The purple line in the centre marks out ‘the path of totality’
Hybrid solar eclipses happen because of the curvature of the Earth.
At any given moment, some points on the planet are closer to or farther from the moon than others.
So when a shadow is cast over the Earth during an eclipse, different parts of the world are in different parts of its shadow.
The centre point of the shadow – which is the point on Earth closest to the moon – and the track it draws across the planet is known as the ‘path of totality’.
Some people stood in the path of totality will be blocked completely from any sunlight by the moon, so will see a total solar eclipse.
But as the moon continues along its path, it will get slightly further away from the Earth, making it appear smaller and not cover covering as much of the sun.
Those stood in the path of totality at this point will see an annular solar eclipse.
Finally, people stood in the moon’s shadow but not in the path of totality will experience a partial eclipse.
So on Thursday, as the the sun, moon and Earth line up, people in Western Australia, East Timor and Indonesia will be closer to the moon than those who are positioned further around the curvature of the Earth.
Because of this, people in these locations will be perfectly placed to see a total solar eclipse.
Meanwhile, those further along the path of totality will see an annular solar eclipse, because they will be just that bit further away from the moon.
On Thursday, as the the sun, moon and Earth line up, people in Western Australia, East Timor and Indonesia will be closer to the moon than those who are positioned further around the curvature of the Earth. Therefore the moon will appear bigger and block more of the sun. Time in top right corner is given in UTC
A solar eclipse occurs in the daytime at new moon – when the moon is between Earth and the sun – and blocks out some or all of its light
Like any eclipse, it’s important that skywatchers do not look directly at the sun with the naked eye while the event is happening, even with sunglasses on.
It is also not wise not to look at the sun through binoculars, telescopes or a telephoto lens on an SLR camera.
Using a simple pinhole projector, solar eclipse viewing glasses, which can be purchased online, or special solar filters are viable alternatives.
‘The simplest way to watch an eclipse is to use a pinhole in a piece of card,’ said Dr Robert Massey at the Royal Astronomical Society.
‘An image of the sun can then be projected on to another piece of card behind it (experiment with the distance between the two, but it will need to be at least 30cm).
‘Under no circumstances should you look through the pinhole.’
Dr Massey said another popular method used to view an eclipse is the mirror projection method.
‘You need a small, flat mirror and a means of placing it in the sun so that it reflects the sunlight into a room where you can view it on a wall or some sort of a flat screen,’ he said.
‘You may also have eclipse glasses with a certified safety mark, and these are available from specialist astronomy suppliers.
‘Provided these are not damaged in any way, you can then view the sun through them.’
Binoculars or telescopes can also be used to project the image of the sun.
‘Mount them on a tripod, and fit one piece of card with a hole in it over the eyepiece, and place another between 50 cm and a metre behind it, Dr Massey said.
‘Point the telescope or binoculars towards the sun and you should see its bright image on the separate card.’
