It’s the first total lunar eclipse of 2022. Fans (not fans) of observing the sky can find at dawn on Monday, May 16, a “blood moon.” It is a different eclipse – the moon will remain fully visible, but with red colors covering its surface.
That’s at least our view of observers on Earth. The total lunar eclipse begins at 4:29 AM (mainland Portugal time), with its maximum point at 5:12 AM. The moon begins to leave the Earth’s shadow around 6 am. According to the Lisbon Astronomical Observatory, if weather conditions allow, it will be possible to follow this phenomenon until the moon leaves almost the entire shadow of the Earth, on the mainland of Portugal. In the archipelago of the Azores (where the distance from the mainland is one hour less) and Madeira, it will be possible to see the moon coming out of the full shadows, as the moon sets later on the Portuguese islands.
Almost everywhere in the world, this total lunar eclipse will be visible. The natural satellite of our planet turns a reddish color – and we’ll explain how this happens in a moment.
A total lunar eclipse occurs when the Sun, Earth, and Moon are aligned correctly so that the Moon is in our planet’s shadow—which only occurs two to three times a year, as the satellite’s natural orbit is tilted.
Most eclipses are not complete and this phenomenon only occurs during the full moon phase (where the moon is from Sunday to Monday). A total eclipse only occurs when the entirety of a natural satellite is within the cone of the Earth’s shadow – known as the shadow. And the reddish tones? This is simply because the Earth’s atmosphere acts as a filter for sunlight. This filter allows for red tones more effectively and reflects green and blue (hence the blue of the daytime sky). That is, when the sun’s rays indirectly hit the moon, they illuminate the natural satellite with the red tones that this filter missed. Without our planet’s atmosphere, the moon would be dark when it entered the shadow area.
At dawn on Monday, the moon begins to enter Earth’s penumbra at 2:31 a.m., when our natural satellite begins to darken. Starting at 3:28 a.m., it will begin to acquire more reddish-brown hues, resulting in the formation of the so-called “blood moon”.
watching the moon
The best time to observe the entire moon is when it rises or sets: Sunday at 8:11 p.m. and Monday at 6:28 a.m., respectively. According to the Lisbon Astronomical Observatory, our natural satellite will appear as a red giant – however, this is not the same phenomenon that occurs during a total eclipse.
During a total lunar eclipse, when it is in the Earth’s shadow, the natural satellite receives indirect light through Earth’s atmosphere. Through refraction, the light is filtered and directed toward our natural satellite – resulting in a reddish hue we can see on Mondays at dawn.
The “blood moon” phenomenon will begin at 3:28 AM. At dawn on Monday, the moon begins to enter Earth’s shadow at 2:31 a.m., at which point our natural satellite begins to darken. Starting at 3:28 a.m., it will begin to acquire more reddish-brown hues, resulting in the formation of the so-called “blood moon”.
The total lunar eclipse will have a long, 85-minute observing period between the phenomenon’s beginning and end – which will occur between 4:29 a.m. and 5:54 a.m. on Monday.
The largest total eclipse of the century, as it did in 2018, will not be on a summer night when we can also see Mars, Jupiter and Saturn. The next total lunar eclipse will occur on November 8th. Before that, we still have a partial solar eclipse on the morning of October 25th.