On Wednesday morning, almost everyone on the east coast in the Americas and in eastern Asia, the Pacific Islands, and Australia will get the rare opportunity to see a special type of lunar eclipse called a selenelion, or horizontal, lunar eclipse.
A selenelion occurs only when a lunar eclipse happens at about the same time as sunrise, allowing observers to see both an eclipsed moon setting and a sun rising simultaneously.
According to simple geometry, we should not be able to see both the moon and the sun simultaneously during this eclipse configuration. However, Earth’s atmosphere bends the light from the sun and moon, making them appear higher in the sky than they actually are.
So, on Wednesday morning, for between two and nine minutes, you might get the chance to see both moonset and sunrise at the same time, which is very rare.
Wednesday morning’s total lunar eclipse, which will be the last total lunar eclipse this year, will begin at 4:45am ET and end at 9:05am ET. However, the most brilliant part of the eclipse, when the Earth completely shadows the moon from the light of the sun, will start at 6:25am ET and end at 7:24am, lasting 59 minutes.
It is during this window that the moon will take on its infamous blood-red hue.
Check out the time the sun rises in your area and make sure to keep a watchful eye on the east and west horizons to get your chance to see sunrise and moonset at the same time.
When Earth passes exactly between the sun and the moon, two types of shadows result: the penumbra (Latin for “almost shadow”) and the umbra (Latin for “shade”). Technically, a lunar eclipse begins when the moon passes through the first penumbra, but it’s not until the moon reaches the umbra that it adopts its menacing colour. The moon’s path between these shadows is shown below.
As the map above indicated, the West Coast will be the best place in the Americas to observe the eclipse. The east coast will still see a nice show but will not see the lunar eclipse in its entirety. Some areas on Earth can see certain parts of a lunar eclipse while others cannot depending on the timing.
For example, in this case, Africa will be on the day-side of Earth and therefore miss the show.
As for the US, many areas will have clear weather, according to AccuWeather:
Stargazers on the West Coast and East Coast will see the eclipse unfold at the exact same time, but the moon will be lower in the sky in the East as the moon begins to set while it is eclipsed. For those in the East, a clear westward vantage point will be needed to catch the final moments before moonset and sunrise.
Clouds and rain may limit viewing of the eclipse in the northeastern US as a storm system swings in from the southwest. Much of the southern and central US will have clear viewing under clear or partly cloudy skies. Meanwhile, thick clouds and rain may hinder the view of the eclipse over the Southwest.
The moon takes on a deep-red colour during a lunar eclipse because of the Earth’s atmosphere. If you were on the moon during a lunar eclipse, Earth would have a red ring around it as it passed between you and the sun. This red glow projects onto the moon, giving it its red hue during a total eclipse, as shown below.