The evening July 27 and the morning of July 28 will have the longest lunar eclipse of the 21st century, lasting approximately 103 minutes. Australia has a great view of the eclipse. The west coast and central Australia will be able to see all of the total eclipse while on the east coast, you will be able to see the eclipse start and the eclipsed moon set. Watching this eclipse will be a great way to spend a Friday night and Saturday morning in July.
Photo courtesy of DVIDSHUB at Wikimedia
What is a Lunar Eclipse
A lunar eclipse, also known as a blood moon, is when the Earth gets in the way of the Sun's light. As the moon reflects light from the sun, what you will see the Earth's shadow on the moon.
The name blood moon comes from the fact that the moon will appear red in colour, rather than just go black. This is because light that is passing through the earth's atmosphere is still hitting the moon. In other words, you are getting a sunset on the moon. If you see photos of the moon with a black shadow, that is usually because the photo was underexposed.
The lunar eclipse is divided into 3 stages. The first is the penumbral stage, which is where the moon's light dims as some light is blocked by the Earth's atmosphere. Then, when Earth's full shadow goes across the moon, a red shadow will start to appear on the moon until a total eclipse is seen and the moon is a uniform dark red.
Image courtesy of Matthew Zimmerman at Wikimedia
While the eclipse itself is 103 minutes, the total process lasts for more than 6 hours. However, only the eclipse itself is really interesting to most people.
Viewing the Eclipse in Australia
Australia will get a pretty good view of the Lunar Eclipse as the moon sets, with the west coast getting the best view of the actual eclipse and only missing the last of the penumbral darkening as it sets.
You don't need to go anywhere special to see a lunar eclipse as the moon should be visible from everywhere. But it is best viewed from a dark place such as a park, beach or bushland area. As the moon will be approaching the horizon or setting for most cities, a place with a view of the western horizon is ideal.
In Brisbane the penumbral eclipse starts at 3:14 am on July 28 while the partial eclipse starts at 4:24 am. The full eclipse will occur at 5:30 am and it will set at 6:35 am while still eclipsed. Sunrise is at 6:32 am, so the moon will be setting while the sky is beginning to lighten.
In Sydney, the penumbral begins at 3:14 am, partial begins at 4:24 am, the full eclipse starts at 5:30 am and the moon will set at 6:55 am while still fully eclipsed. Sunrise will be at 6:51 am.
Down in Melbourne, you will be able to see all of the fully eclipsed moon. The penumbral eclipse will start at 3:14 am on July 28, the partial eclipse at 4:24 am, with the full eclipse running from 5:30 am to 7:13 am. The moon will set partially eclipsed at 7:29 with the sunrise at 7:24 am.
Adelaide people will be able to see nearly all of the eclipse with the partially eclipsed moon setting just before that stage of the eclipse ends. So the penumbral begins:2:44 am, but the more interesting partial eclipse begins at 3:54 am, not too early to get out of bed for. The total eclipse starts at 5:00 am and ends at 6:43 am. Most people could get out of bed by that time even on the weekend. The moon will set at 7:19 am still partially eclipsed, 5 minutes after sunrise.
For the lucky people of Perth, you will be able to see the eclipse in its entirety. Of course, that also means that you have to either stay up late or get up early to see it. The penumbral dimming begins at 1:14 am and the partial eclipse at 2:24 am. The full eclipse goes from 3:30 am through to 5:13 am and the last of the partial eclipse ending at 6:19 am. The last of the penumbral eclipse will occur at 7:17 am, 8 minutes after sunrise.
Photographing a Lunar Eclipse
Photographing the moon is fairly simple, but photographing a lunar eclipse is a little more challenging because of the changing brightness of the moon over the course of the eclipse. If you don't change the settings during the eclipse either the eclipsed moon will be too dark or the moon will be over exposed.
The most basic thing that you need is a camera which you can manually control the aperture and shutter speed. This includes DLSRs, mirrorless cameras as well as some other cameras which also have this capability. You also need a tripod and ideally a remote control to avoid camera shudder when you press the button. You can also achieve this by using the camera's timer if you don't have a remote.
Multiple exposure photograph courtesy of U.S. Army Alaska (USARAK)
So if you photographing the moon normally, you might use an aperture setting of f/8 or f/11 at 1/60 or 1/125 of a second. It is worth trying a few photos of the moon before the eclipse to work out what works best for your camera. Remember that as the eclipse starts, the moon will first go a bit dimmer than normal during the penumbral phase of the eclipse.
When the moon is about half obscured you want to double the length of your exposure so maybe around 1/30 of a second but leave all the other settings the same. But play around with this because if you underexpose the eclipsed part of the moon, it will appear black in your photo rather than blood red.
As the moon becomes more and more eclipsed you will want longer and longer exposures. You can increase the expose length, but because the moon is moving across the sky, longer exposures will make the image look fuzzy. You should also try increasing the ISO. So you might have started with an ISO of 200 for the normal full moon and when the moon is fully eclipsed you might be using one of 1600 or higher.
This is definitely an interesting astronomical event to get up early or stay up late to see. You should get a good view no matter what part of Australia you are in, especially as it happens early on Saturday morning here.