A rare lunar phenomenon called the ‘black moon’ is set to occur tonight – giving stargazers a unique view of the night’s sky.
This unusual astronomical event, occurring only once every 29 months, has fascinated humans for centuries.
A black moon is simply the second new moon in the space of a calendar month – the first lunar phase when the moon’s shadowed side is pointing towards us.
Because it’s a new moon, the black moon cannot be seen, not even with a telescope.
But it should provide an excellent stargazing opportunity after sunset and into the wee hours of Tuesday.
The moon will be notable by its absence in the night’s sky, as if it’s been blotted out by the gods, while the stars and planets will appear particularly bright.
Top tips for stargazers include choosing a spot with a wide an unobstructed view of the sky, away from artificial lights such as streetlamps.
You won’t want to miss it – as the last black moon was back in April 2022, while the next one after tonight won’t be until August 2027.
A new moon is when our natural satellite has 0 per cent illumination, so it the lunar disk is invisible to the unaided eye (file photo)
The reason for a black moon, as it’s commonly termed by amateur astronomers and space fans alike, is quite simple.
Over 29.5 days, the moon goes from a new moon (with 0 per cent illumination as seen from Earth) to a full moon (100 per cent illumination) and back again.
Because the lunar cycle (29.5 days) is shorter than months of the year, sometimes there are two new moons in a month rather than just one.
When this happens, people refer to the second new moon of the month as the black moon – an event interpreted by some astrologists as spiritually significant.
However, beyond the fact it’s a new moon, scientists don’t tend to see the black moon as a meaningful event.
‘A black moon is just a second new moon that happens in one calendar month,’ said Walter Freeman, associate teaching professor of physics at Syracuse University.
‘If a new moon happens near the beginning of a calendar month, then the next one will happen before it’s over.
‘This is no different than any other new moon from the perspective of science.’
During the 29.5-day lunar cycle, we observe a new moon (with 0 per cent illumination), a waxing moon (when the amount of illumination on the moon is increasing), a full moon (100 per cent illumination) and then a waning moon (when its visible surface area is getting smaller)
Images show the new moon, waxing moon, full moon and waning moon as they look during the 29.5-day lunar cycle
This month’s first new moon happened on December 1, while the second new moon of December (the black moon) is December 30.
It is set to occur on December 30 at 22:27 GMT (17:27 EDT), according to the US Naval Observatory.
This marks the precise astronomical moment when the moon gets directly between the Earth and Sun, while the side of the moon that is in shadow faces Earth.
According to Professor Freeman, there’s ‘nothing to see’ when it comes to the moon itself, but the lack of moonlight creates ideal conditions for stargazing, making it easier to spot constellations such as Orion, Taurus and Leo.
It’ll also be easier to see planets such as Venus – the brightest thing in the sky with a very subtle yellow tint.
Mars should also be visible, appearing as a reddish dot, close to the constellation of Cancer the crab.
Members of the public don’t need a telescope to view the planets, which will be best viewed in clear skies free of cloud.
In a sky full of stars, the planets can be identified by their distinct lack of twinkling.
Tonight, the lack of moonlight due to the new moon creates ideal conditions for stargazing. Mars should also be visible, appearing as a reddish dot, close to the constellation of Cancer the crab (left)
Stars twinkle, while planets usually shine steadily.
For the best view, try to find somewhere away from sources of light pollution such as street lights and give your eyes plenty of time to adjust to the darkness.
However, the Met Office warns of ‘generally cloudy conditions’ tonight which could impact visibility.
In London and the southeast, tonight’s minimum temperature will be 44.6°F (7°C), so it’s a good chance to skygaze without getting too cold.
If you miss the black moon, you’ll sooner be able to see the ‘blue moon’ (the second full moon in a calendar month) although it won’t arrive until 2026.
Likewise, this infrequent astronomical event normally happens about every two or three years – hence the phrase ‘once in a blue moon’.
While the next black moon doesn’t occur until August 2027, the next blue moon will be in May 2026.
Meanwhile, there will be two ‘supermoons’ in 2025 – when the full moon appears larger and brighter than usual.
According to Royal Museums Greenwich, the supermoons will arrive on November 5 and December 4, 2025.
