We have a moon eclipse, when the moon enters into the shadow of the Earth. This happens at full moon. The Earth throws a shadow, because she is illuminated by the sun. When the full moon enters the penumbra of the earth the moon will become a little darker. When the moon moves on, he will get darker. When the moon is covered by the umbra. he shines in a dark copper-colored light. At this moment, the lunar eclipse is at the darkest point. When the moon is not covered totally by the shadow of the Earth, we have a partial lunar eclipse. When the moon is far away from the Earth during a lunar eclipse, he cannot be covered fully by the shadow cone and we see an annular moon eclipse.
In 27 days the moon orbits the earth. The moon revolves around itself in 27 days. This phenomenon is known as tidal lock. This phenomenon also appears when a planet surrounds a star at a very near distance. This effect is due to the strong gravitational forces of the star. When a moon comes to close to a big planet, it can be torn apart by the strong gravitational forces of that planet. From one Lunation to the other there are 29 day, from full-moon to the next full-moon.
This had happened to the moons of Saturn. The remaining rocks are surrounding Saturn as the famous Saturn rings. These rings consist of rocks and ice. Don’t panic. Our Moon will not be torn apart. He has the tendency to escape. Someday the moon will be so far away, that there will be only annular solar eclipses The sun cannot be totally covered by the moon at a solar eclipse.
The ecliptic is also called the zodiac. The constellations that saw our ancestors go back to the Greek mythology. So there are the fish. They are in the spring point. This is the point at which the sun, at the beginning of the spring, passes over the sky equator to the north. There is still the autumn point. There in September happens the same, only in other direction. These are also called the equinocts. In English they are called Point of Aries. The vernal equinox is called the ram's point and carries the sign of the zodiac, also known as the zodiacal circle. However, as the aroused man performs a staggering movement, the vernal equinox moves westward and is now in the fish. We find on the ecliptic the ram, the Aquarius, the Capricorn, the Sagittarius, the Libra, the Virgo, the Lion, the Cancer, the Gemini and the Taurus.
The expanding Universe
In the 1920s, Hubble was not only concerned with the expanding universe in America, but also LeMaitre. LeMaitre worked at this time in America working on various Institutions. As a result, he became aware of the measurements of the velocities of the Milky Way galaxies by Vesto Slipher. Slipher worked at Lowell Observatory. Hubble published at this time on the distances of Andromeda galaxy and the redshifts and thus the expansion of the universe. The LeMaitres publications have not become as popular in science as Hubble's.