14 April 2014
This week these of us within the western hemisphere may have the prospect to look at a lunar eclipse. It would occur within the night/morning of April 14/15, reaching peak darkness at about 3 a.m. EDT (0600 GMT). Relying on the darkness of your sky, the Moon could also be invisible to the bare eye, or it could seem as a darkish, blood moon.
A lunar eclipse happens when the Moon passes by means of the shadow of the Earth. For that reason, lunar eclipses happen when the Moon is in its full part. On condition that the Moon orbits the Earth, you would possibly marvel why there isn’t a lunar eclipse each month. If the orbit of the Moon have been precisely in keeping with the orbit of the Solar, then that’s precisely what would occur. However the Moon’s orbit is tilted about 5 levels relative to the orbit of Earth, and because of this the Moon is usually barely above or beneath the Earth’s shadow when it passes by means of its full part. So most months there isn’t a lunar eclipse.
For the Moon to be lined up in the suitable means, it needs to be situated close to the aircraft of the Earth’s orbit when it passes behind the Earth, and this solely occurs twice a 12 months, about 6 months aside. Because of this there are “eclipse seasons” in Spring and Fall. There are not less than two lunar eclipses every year, however there will be as many as 5.
Not all lunar eclipses are alike. As seen within the picture beneath, because the Solar is bigger than the Earth, there are areas the place solely a part of the Solar is blocked by the Earth, and the ensuing shadow is named the penumbra. For a a lot smaller area the place the Solar is totally blocked by the Earth, the shadow is named the umbra. The kind of eclipse that happens is dependent upon whether or not the Moon passes by means of umbra or penumbra.
If the Moon simply passes by means of penumbra, then what happens is a partial lunar eclipse. On this case solely a part of the moon will seem dimmed. If the Moon passes by means of the umbra, you then get a complete lunar eclipse. It’s whereas passing by means of the umbra you could observe a blood Moon. The rationale the Moon can seem purple somewhat than utterly darkish is that some daylight is refracted by the Earth’s environment. In the event you have been standing on the Moon throughout a lunar eclipse you’d see the Earth surrounded by a hoop of sundown.
This specific lunar eclipse is a complete one, and it marks the primary of 4 consecutive whole lunar eclipses. One for every eclipse season each six months. So in case you miss this one, you’ll have one other three probabilities over the following 12 months and a half. After that, whole lunar eclipses can be much less frequent for some time.
So brace yourselves, the eclipses are coming.