A rare supermoon is set to be visible across London this week as the capital enters its final week of summer.
Balmy weather has been forecast for the capital in the days to come, with the Met Office predicting a September heatwave from Tuesday to Thursday.
Unrelated, but not unremoved, is the news that the moon will be at its biggest and most visible for one night only.
It follows a striking red Moon being visible on August 20 across London skies.
Here is what you need to know.
What is a supermoon?
The moon is at its fullest 12 times per year but reaches supermoon status far less often.
The heightened appearance of a supermoon is due to its orbit and cycle.
“A supermoon occurs when the Moon’s orbit is closest (perigee) to Earth at the same time the Moon is full,” Nasa states.
It gives the Moon a slightly fuller appearance, around 2 per cent larger than the average full moon. Nasa has also added that this has impact on tides.
“High tides and low tides will be more extreme with a perigean full moon and more so for an extreme perigean full moon,” the statement continued.
“The extremes are greater due to the difference in the gravitational pull of the Moon across Earth’s diameter. When the Moon is close, Earth’s diameter is a slightly larger fraction of the Earth-Moon separation.
“This means that the Moon’s gravitational pull on the oceans (and Earth’s crust) has a greater difference between the point on Earth closest to the Moon’s center and the point on Earth diametrically opposite it.”
In September, the full Moon is known as the ‘Harvest Moon’ - with a different name being applied to each of the 12 in the annual cycle.
Is the supermoon tonight in London?
The supermoon will be visible from the night of Tuesday, September 17, into the morning of Wednesday, September 18.
The partial eclipse will begin from 1.41am and then the supermoon will become most prominent around 3.44am - remaining in its pomp until 4.16am, writes Time Out.
Here are some of the best places in London to watch such an event.