Venus can still be seen low in the eastern sky in the morning. It slowly withdraws from the morning sky and becomes invisible at the end of September. It will pass the Sun on October 22 and then appear in the evening sky in December. This completes his passage from the morning star to the evening star. We will search in vain for Mercury in September.
The farthest planet from the sun, Neptune in the constellation of Aquarius, comes to oppose the sun on the night of the 16th to the 17th. It is 30 times farther from the sun than the Earth. It takes 165 years to circle the sun once. Due to its great distance, it is so faint that it can only be seen with binoculars or a telescope. Opposition day Neptune separates 4325 million kilometers from the earth. This corresponds to a light autonomy of a good four hours. In a telescope, Neptune appears as a tiny bluish ball.
On the night of the 14th to 15th, the greenish planet Uranus will be covered by the waning moon between 11 p.m. and 12:30 a.m. Exact times depend on location. This event can also only be followed with a telescope.
The Full Moon occurs on the 10th at 11:59 a.m. in the constellation Aquarius. Already on the 7th, the moon approaches the earth at 364,492 kilometers, while on the 19th it separates from us at a distance of 404,555 kilometers. The new moon is reached five minutes before midnight on the 25th.
The earth binds the moon to itself with its gravity. But the sun also attracts the moon with its enormous mass. However, it is 400 times farther from the Moon than Earth. Due to tidal friction, the Moon moves away from the Earth by four centimeters each year. The moon is currently 384,400 kilometers away on average.
How far can he get from us before the sun tears him from the earth? The American astronomer Georg William Hill (1838 – 1914) asked himself this question. In 1877 he came to the conclusion that if the moon moved more than a million miles from the earth, we would lose our night star. The area in which the Earth can bind natural and man-made satellites is called the Hill sphere. So there is no risk of losing our moon. It will stay with us for the next billion years.
A look at the evening sky shows: the celestial chariot descended in the northwest, the celestial W, Cassiopeia, but rose in the northeast. The summer triangle with Wega, Deneb and Atair has clearly shifted to the west. Vega is the bright main star of Lyra, represented by a small but easily recognizable stellar diamond. Between Vega’s two distant stars, you can see a small round patch of light in the binoculars, which turns out to be a ring in the telescope.
This ring nebula is well known to stargazers. Here, an aging star has lost its outer layer of gas, which is expanding into space. What remains is the extremely hot star core. Its intense ultraviolet radiation makes the Ring Nebula shine. Today we receive the light that this star formation emitted 2200 years ago.
The march of the autumn constellations has begun in the eastern sky. First and foremost is the guiding star of autumn: the starry square of Pegasus, also known as the square of autumn. At its northeast corner hangs the star chain of Andromeda. The unfortunate princess Andromeda is saved by the hero Perseus at the last minute before she can be devoured by the sea monster Ketos. Perseus and Ketos, Cetus in Latin, are also depicted as constellations in the autumn sky. In German, Cetus is called a whale. But it is neither a fish nor a whale, but a mythical creature with teeth and claws sharp as daggers.
In the constellation Andromeda, the Andromeda Galaxy can be seen as an elongated patch of light when the sky is very dark and the air is clear. It is our neighboring Milky Way. Their more than 400 billion suns are 2.5 million light-years away from us.
The Sun passes from the constellation of Leo to Virgo in the early hours of the morning of the 17th. On the 23rd, it crosses the celestial equator in a southerly direction at exactly 3:04 a.m., the autumnal equinox is reached. The diurnal and nocturnal solar arcs are of equal size on this day. The winter semester begins with the autumnal equinox.
Lifelong zombie fan. Twitter evangelist. Unapologetic travel buff. Hipster-friendly introvert. Typical creator