We can see 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 become darker, when she enters the shadow of the Earth. When the moon is covered by the umbra. she shines in a dark copper-colored light. The red lieght could be very darkly red, red or even orange. At this moment, the lunar eclipse is here isat 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 surrounds 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. Tidal look means that the revolution time of the Moon is the same time as his revolution around the Earth.
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 Greek mythology. The point at which the sun, at the beginning of the spring, passes the equator to the north is called the spring point. In September happens the same, but in other direction. The point is called the autum point. These points are also called the equinocts. We find on the ecliptic the constellation of Pisces, the Aries, the Aquarius, the Capricorn, the Sagittarius, the Libra, the Virgo, the Lion, the Cancer, the Gemini and the Taurus.
The axis of the Earth describes a circle in 26 000 years. So the axis points in different time periods to other stars. So the polarstar is changing through the centuries. In 11,000 years we will have Wega as our polar star at the northern hemisphere. The equinoctes are also chaning. The sping point, that is also called the point of Aries, and stood in the constellation of Aries 2000 years ago, had beed been wandering into the Pisces.
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.