What will the eclipse look like?
In a lunar eclipse the moon appears darkened as it passes into the Earth's shadow, taking on a reddish or coppery hue – the intensity and exact shade depends on the amount of dust particles and clouds in the atmosphere, but it may look a little bit like when the sun sets on the horizon.
A super blood moon in Malmö in 2015. Friday's blood moon won't be as big. Photo: Johan Nilsson/TT
Why does the moon turn red in a Blood Moon eclipse?
The red moon is possible because while the moon is in total shadow, some light from the sun passes through the Earth's atmosphere and is bent toward the moon. While other colours in the spectrum are blocked and scattered by the atmosphere, red light tends to make it through easier.
What time will you be able to see it?
In Sweden the spectacle will start at 9pm on south-eastern Gotland, when the moon climbs above the horizon. In Malmö and Stockholm this will happen at 9.15pm, in Gothenburg 9.30pm, Umeå 9.45pm, Östersund 10pm and 11pm at the northernmost tip of Sweden, Treriksröset.
Because the moon is further away from Earth than it normally is, it will look smaller than usual. But on the upside it means it will also take longer for it to pass through the Earth's shadow, making the lunar eclipse the longest eclipse of this century – it is expected to last for almost two hours.
Those in the south of the country will be better placed to see it than those in the north. This is partly because the moon is lower in the sky in the north, and partly because the northern light summer nights mean that the blood colour will not be as clearly visible.
A blood moon in San Francisco on January 31st, 2018. Photo: AP Photo/Noah Berger
What is the weather forecast?
If you have spent this summer in Sweden you know that it has been one of the sunniest (and also hottest and driest) summers in recent times, and we're expecting clear skies in most of the country tonight. The only issue may be that the night sky may not be dark enough this time of the year.
The midnight sun in northern Scandinavia. Photo: Håkon Mosvold Larsen/Scanpix Norge
Should I protect my eyes?
There is no need to take precautions when it comes to looking at the eclipse, scientists have said. In fact, it will be easier to look at than a normal full moon because it will not be as bright. And you don't have to worry about having a telescope, with astronomers saying that there is no need for special equipment.
What a lunar eclipse can look like. Photo. AP Photo/Arnulfo Franco
Why is this lunar eclipse special?
Not only will you be able to see the blood moon tonight, you may also get a glimpse of the planet Mars, which is at its closest to Earth in 15 years. It will look bigger and shine stronger than normal. Look for it just under the moon.
The planet Mars, seen here left centre. Photo: AP Photo/Dr. Scott M. Lieberman
When will I get a chance to see a blood moon again?
The next total lunar eclipse will happen on January 21st, 2019.