Super Total Lunar Eclipse – 21 January 2019
On Monday morning, 21 January 2019, the setting Moon will turn red as we experience a total lunar eclipse.
A Celestial Spectacle
In the early hours of Monday morning, 21 January 2019, we’re in for a celestial spectacle here in the UK, so if the skies are clear head outside and look up!
The main event will be a total lunar eclipse of the Moon. Although we call it an eclipse, the Moon will not completely disappear but instead appear blood red as the Earth blocks the majority of the Sun’s light and its shadow darkens the face of the Moon.
But you’ll need to be up early to catch it. From the UK, this total lunar eclipse will take place between 4:41am GMT and 5:44am GMT on Monday morning, just as the Moon is setting, and before the Sun rises. Mid-eclipse occurs at 5:12am GMT.
Unlike a solar eclipse you will not need any safety filters, and no telescopes required. Just find a clear view of the south western sky and watch the Moon rise red! If it’s cloudy, see below for how to watch live online.
What is a total lunar eclipse?
A total lunar eclipse occurs when the path of the Earth brings it directly between the Sun and the Moon, blocking the Sun’s light. As this happens, the face of the Moon darkens. Literally, Earth casts a shadow which falls on the Moon across nearly 400,000 kilometres of space!
Some of the Sun’s light does make it to the Moon, after first filtering and bending through Earth’s atmosphere. This filtered light is mainly from the red end of the spectrum, giving the Moon a reddish hue. The same effect is the reason why sunsets look red – so you can think of a lunar eclipse as the Moon being bathed in the light from a global sunset.
A total lunar eclipse can last for up to five hours, depending on the exact locations of the Moon, Earth, and Sun.
It’s also possible to get partial lunar eclipses, where the Moon and Earth don’t exactly align and the Moon passes through just part of the Earth’s shadow.
Lunar eclipses of any type occur several times a year somewhere in the world. But because of the Earth’s rotation, only the countries that happen to facing the Moon during the few hours of the eclipse can see it.
Total lunar eclipses are more rare and occur slightly less than once a year (about two total lunar eclipses every three years to be exact!). And you have to lucky to be in the right place when it takes place! The last total lunar eclipse visible from the UK was in July 2018.
A total lunar eclipse is also known as a “Blood Moon” and used to be considered a bad omen by ancient civilisations.
On the 21 January 2019, the Moon will also be a ‘supermoon‘, which means that it is closer to Earth than usual and will look slightly bigger and brighter in the night sky.
The reason the Moon varies in size is because the Moon’s orbit around the Earth is not a perfect circle but is instead an ellipse. This elliptical orbit means that the distance between the Moon and the Earth changes as it loops around our planet. At its closest approach (known as ‘perigee’) the Moon is about 363,300 kilometres from the Earth whilst at the furthest point (‘apogee’) it is 405,500 kilometres away.
A supermoon occurs when the Moon is near perigee making it appear about 15% larger in the sky and brighter than a normal full Moon.
In 2019, supermoons will occur on: 21 January 2019, 19 February 2019, and 21 March 2019.
Watch live online
If skies are cloudy where you live, or if 5:00am is just too early to be outside, you can also watch this super total lunar eclipse live from the comfort of your home.
There are lots of websites that will be live streaming the eclipse from observatories or clear sky locations, including timeanddate.com.
Their stream starts at 3am but the actual total eclipse reaches mid-point at 5:12am GMT.
About the author: Dr Tamela Maciel is the Space Communications Manager at the National Space Centre