Tomorrow, Saturday, October 28, there will be a partial lunar eclipse that will be visible from Europe, Asia, Oceania, Africa and eastern America.
Although the magnitude of the eclipse will be low, since at the moment of maximum occultation the lunar disk will be shadowed by only approximately 12% of its surface (according to data from the National Astronomical Observatory), careful observation of the phenomenon will allow us to contemplate how the eclipse progresses. typical “bite” in the lower limb of the Moon.
The beginning of the partial eclipse will take place at 9:35 p.m. (Spanish peninsular time), when a part of the Moon begins to enter the Earth’s shadow cone and is no longer illuminated by the Sun. The maximum will occur at 22:14 and the partial phase of the eclipse will end at 22:53.
Lunar eclipses occur when the Sun, Earth and Moon align in this order. Then, the shadow cast by our planet prevents sunlight from illuminating the lunar disk and a part of it (or all of it) becomes dark.
In reality, the Earth’s shadow is made up of two different regions, called umbra and penumbra. The umbra is the deepest part of the shadow. From this area of ??space, the Sun is completely hidden by our planet, so that the umbra is in darkness. However, in the penumbra zone (surrounding the umbra) the solar disk remains only partially hidden by the Earth.
In a total lunar eclipse, our satellite completely enters the Earth’s umbra and stops reflecting sunlight. At the moment of maximum, the Moon acquires a dark reddish color, a product of the faint illumination generated by our planet’s atmosphere. At that time, an observer from the Moon would see a total solar eclipse, that is, an occultation of the Sun by the Earth.
On the contrary, in partial eclipses, as is the case tomorrow, Saturday, it is only a fraction of the Moon that moves through the Earth’s umbra and is shadowed. And in the so-called penumbral eclipses, the lunar disk does not penetrate the Earth’s umbra but only into its penumbra. In these cases, the result is an almost imperceptible decrease in the brightness of our satellite.
Due to the geometry of lunar eclipses, they always occur when the Moon is in a full phase (Sun, Earth and Moon alignment).
However, not all full moons generate an eclipse. The reason is that most of the time, the alignment is not perfect, and the Moon passes close to the Earth’s shadow cone but without entering it.
Unlike what happens with solar eclipses, observing lunar eclipses does not require any instrument and can be done with the naked eye. In any case, simple binoculars help to better perceive the phenomenon.
Although the quality of the observation will be higher if you access dark skies without light pollution, tomorrow’s partial eclipse can be seen from practically anywhere as long as the weather allows it.
According to the National Astronomical Observatory, between 4 and 7 eclipses occur each year, including solar and lunar eclipses, although their visibility depends on the geographical location of the observer.
After tomorrow’s one, we will have to wait until September 18, 2024 to be able to contemplate, from Spain, a new partial lunar eclipse. And the next total lunar eclipse will not arrive until March 14, 2025.