Astronomy and Books


Moon eclipses

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.

Why do we always see the same side of the moon - Tidal Lock

In 27 days the moon circles  the earth, and during the same period spins around itself . This phenomenon is known as tidal lock. This phenomenon  also occurs   when a planet surrounds a star at a very close distance.  This effect comes from the  strong gravitational forces of the star. Also when a moon in our Solar system  come too close to a big planet, the moon could  be torn apart because of the strong gravitational forces of the big planet. These could happend to moons, that came to close to Jupiter or Saturn.  

The revolution of the Moon in 27 day is aloo called the sideral month, (the time when we can see the same star again). The duration of the Lunar phases, (from full-moon to full.moon) is 29 days. This duration is called the synodic month, from one synode to the next.     

Where Does The Rings of Saturn Come From?

The rings of Saturn consist of rock and ice. The rocks are the remnant of a moon that had been torn by the gravitational forces of Saturn. The ice particles come his moon Enceladus. Geysires on  Enceladus surface are constantly trowing particles into space. But don’t panic:. Our Moon will not be torn apart. He has the tendency to escape. In the distant future the moon will be so far away from the Earth, that there will be only annular eclipses, for the sun cannot be totally covered by the moon because of his distance.

The Ecliptic

The ecliptic is also called the zodiac. The constellations our ancestors saw,  go back to  Greek mythology.  The point at which the sun, at the beginning of the spring, passes the equator northwards,  is called the vernal equinox. At the beginnung of autum the sun desendes at the  equator at the autumnal equinox    We find on the ecliptic the constellation of Pisces,  Aries,  Aquarius,  Capricorn,  Sagittarius,  Libra, Virgo,  Lion, e Cancer,  Gemini and Taurus.

The Precession of the Earth's Axis

The axis of the Earth describes a circle in a periord of 26 000 years. So the axis points to diffent polar stars. In 11,000 years Wega in the constellation Lyra will be our polar star at the northern hemisphere. The equinoctes are also wandering around the ecliptic. 2000 years ago the vernal equinox, also called the  the point of Aries,  was situated in the constellation of Aries. In the past 2000 years the vernal equinox had wandered  into the Pisces.  

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.