Tonight's Supermoon Blood Moon will be the last time the two stunning lunar events will coincide for 18 years.
For the first time this century, tonight will see a Supermoon, when it is close to Earth and therefore unusually big and bright, that will coincide with a lunar eclipse, where the Earth moves between the sun and the moon and scatters the light so that the moon turns red. And it won't happen again until 2033.
Supermoons aren't uncommon, and lunar eclipses happen less often but also aren't rare. But the collision of the two is very uncommon — it's only happened five times since 1900, the most recent of which was in 1982.
Watch the video below for Nasa's explanation of why the spectacle happens:
It will also be the last chance to see a total lunar eclipse on Earth until 2018. That will be after the stunning total solar eclipse that is set to come to the US the year before, an event that is set to spur the biggest movement of people for tourism purposes in history.
In pictures: Super Blood Moon
In pictures: Super Blood Moon
The supermoon rises behind Glastonbury Tor in Somerset, England
The super moon rises above Brighton, England
A full moon silhouettes television and radio antennas on Boutilier Mountain, in Port-au-Prince, Haiti
A super moon rises in the sky near the Eiffel tower as seen from Suresnes, Western Paris, France
A flock of birds fly by as a perigee moon, also known as a super moon, rises in Mir, Belarus, 95 kilometers (60 miles) west of capital Minsk, Belarus
A supermoon rises over a minaret of a mosque in Wadi El-Rayan Lake at the desert of Al Fayoum Governorate, south west of Cairo, Egypt
The moon rises through the mist of the north east coast ahead of a lunar eclipse
A partially eclipsed supermoon, the last of this year's supermoons, rises over Las Vegas, Nevada
The supermoon is seen in Bogota, Colombia
The supermoon, prior the beginning of a total lunar eclipse, in Bogota, Colombia
A perigee full moon is seen during a total lunar eclipse behind The Colorado State Capitol building in Denver, Colorado
A supermoon, is seen next to the Empire State Building in New York City
A blood moon rises behind a hilltop residence in Solana Beach, California
The moon appears behind the monument at the San Nicolas church in Cali, Colombia
The moon enters the maximum eclipse in Glastonbury, England
A swollen 'supermoon' bathed in the blood-red light of a total eclipse is seen in Strasbourg, eastern France, early on September 28, 2015
The Super Blood Moon rises over a sailboat in Boston Harbor on September 27, 2015 in Boston, Massachusetts
The moon turns red during a total eclipse, seen behind the iconic Liver Bird on the Liver Building in Liverpool, north west England, early on September 28, 2015
Rising over the Lower Fox Creek School near Strong City, Kan
The Supermoon above the Notre-Dame de la Garde basilica in Marseille
The Supermoon will be visible for all of the night of 27 September and the morning of 28 September. But the total eclipse will last just over an hour, occurring in the very early morning in Europe and Africa and the evening for the Americas.