Today, the Moon is in first quarter phase and has only a quarter orbit to go before to meet the Earth’s shadow cone The partial eclipse will begin September 28 in 4:07:11 in Moscow, and the full phase in 5:11:10 Maximum is expected at 5:47:07 in an already bright sky just before dawn. Unfortunately in Moscow the moment of coming out of the shadow is not visible – half an hour after the maximum the Moon will hide behind the horizon and the Sun will rise.
Early Monday morning is not the most convenient time, and the visibility of the full phase is far from ideal (Moon height is less than 10 degrees).Nevertheless, I still suggest watching this phenomenon for the following reasons :
- This eclipse will coincide supermoon and the Moon will be slightly larger than usual, and the proximity to the horizon will further enhance the effect (see illusion of the moon ).
- The next total lunar eclipse visible in the European part of Russia will occur only July 27, 2018.
Note. The times indicated are true for any time zone-adjusted observer’s location. Only the position of the Moon in the sky will vary. Unfortunately, for many of our compatriots (e.g. Siberians), the eclipse will occur after the Moon sets. Visibility conditions described here are true for Muscovites and residents of neighboring regions.
Choosing a place to observe
If your window faces west or southwest and the view of the horizon is not blocked by houses and trees, you are lucky and can watch the eclipse from home. Otherwise, you’ll have to find a suitable observation site. The sky in a westerly direction should be visible up to at least 5 degrees, otherwise you won’t see the full phase. For the rest of the week before the eclipse, the Sun will be in the correct area of the sky at about 5:20 pm (± 5 min).Use this fact to see if you can see the full phase from your chosen location – it should be illuminated by the sun’s rays at 5:20 p.m.
If you have a camera with a telephoto lens, take it with you. You can get by without a tripod for partial phases, but for the full phase it’s better to mount your camera – the lunar disk will darken a lot and you’ll need a faster shutter speed.
The penumbra phase of the eclipse will begin at 3:11:47 but you’re unlikely to see any changes with the naked eye. But if you take a picture of the moon after about half an hour, you will see in the photo that the full lunar disk is irregularly illuminated – the left edge is darker. This is explained by the fact that for an observer on the Moon at that moment the Sun is already partially covered by the Earth, and the degree of closure differs for different points on the surface. By the way, a picture of the full Moon before the penumbra phase will be interesting because it will be the fullest Moon you can photograph from Earth (usually on a full Moon one edge of the Moon is a bit flaky, see “The full Moon”). have you ever seen a full moon ).
Shortly before the beginning of the private eclipse, a slight darkening of the upper left edge of the lunar disk will already be visible to the eye.
Then the Moon will suddenly lose its perfectly round shape – a private phase will begin.
Position of the Moon among the stars of the constellation Pisces at the moment the shadow touches :
At about 4:45, the shadow of the Earth will cover half of the lunar disk. The moon will have dropped to 13º above the horizon by then.
During the private phase, the brightnesses of the shaded and bright parts of the disk are very different. The eye can see both parts well, but the camera doesn’t have enough dynamic range for the whole moon. You can try to take an HDR photo :
Beginning of full phase, height just under 10º:
Maximum. It is already light, the Sun is only 5º below the horizon, and the Moon is 5º above – at the moment of lunar eclipse they are diametrically opposite points of the celestial sphere (corrected for refraction and finite shadow dimensions).
The north pole of the Moon will appear darker as it passes closer to the center of the Earth’s shadow.
Why the Moon turns red
The red color of the Moon during the full phase is due to the same reasons we see red dawn after sunset (cf. Diffuse sky radiation ).
The observer on the Moon seems to see dawn simultaneously around the entire circumference of the Earth’s disk.
This model taken from the wikipedia article is very crude – the glow of the cities on the night side is exaggerated, and the ring of dawn should not be so uniformly colored. The only real photo of the Earth from the surface of the Moon during the lunar eclipse was taken by the Surveyor 3 in 1967 :
The uneven ring width is due to differences in weather conditions and atmospheric conditions.
This image was taken by Apollo 12 but not from the surface, on the way home:
And the Japanese probe Kaguya even made a video of Earth rising over the moon’s north pole during the eclipse February 9, 2009 The video was not taken from the surface, but from polar circumlunar orbit.
This eclipse was visible from Earth as a penumbra eclipse, with the moon then almost touching the shadow with its northern side. Kaguya was in a polar orbit and still passed through the shadow flying over the area of the north pole of the Moon.
Interesting that a week ago (i.e. half a whirl before the upcoming eclipse) there was a partial solar eclipse visible in southern Africa and part of Antarctica. The spacecraft SDO (Solar Dynamics Observatory) is lucky enough to be close to a straight line passing through three celestial bodies at once – the Sun, Moon and Earth (in descending order of distance from the spacecraft). The result is this rare shot of a double solar eclipse taken in the far ultraviolet:
The Moon has no atmosphere and the edge of its disk (pictured left) is sharp. Earth’s atmosphere causes the edge of Earth’s disk to blur (dark arc above).
Eclipses of the Sun by other planets with atmosphere An image taken from Pluto’s shadow by a spacecraft New Horizons :
In the photo album Cassini there is such a magnificent frame :
The point to the left of the rings is Earth.
Short-lived lunar phenomena
If you have a telescope, try examining the shadowed lunar surface at maximum magnification – there is a rare chance of detecting the so-called short-lived lunar phenomena During a lunar eclipse, the temperature of the red-hot daytime surface of the Moon drops very sharply. Due to mechanical stresses in the rocks, an electric field can arise causing ionization and glow. The nature of these phenomena and the very fact of their existence are still the subject of debate. Until now there is no reliable confirmation of the same event by several observers.
Update: What else will be visible in the sky during the lunar eclipse?