Astronomy Day on October 19, comet in the evening sky, ringed planet Saturn.

Astronomy Day was held for the first time on 23.08.2003 to mark the particularly close opposition of Mars. Until the beginning of the corona epidemic in 2020, it took place in March/April. From 2022, it was moved to the fall due to the better visibility of the planets.

As a special feature this year, a bright comet is expected in the evening sky. If it continues to develop in this way, it will also be visible to the naked eye. However, predicting the brightness of comets is difficult, which is why David H. Levy, a well-known amateur astronomer, coined the phrase "Comets are like cats: they have tails and do precisely what they want". Due to the loose composition of comets - they are also known as dirty snowballs - they often break up when they come too close to the sun. This was the case with comet ISON C/2012 S1. Here is a time-lapse image of the comet before and after its closest approach to the sun. The individual fragments of the comet after its closest approach are clearly visible.

The ringed planet Saturn is also easy to observe in the evening sky. The special feature is the small ring aperture of just four degrees. In March 2025, we will look at the edge of the rings for a few weeks. They will then be invisible.

Starting this month, we will open our observatory on Friday evenings from 8 p.m., provided the night sky is clear. On Friday 18.10. and Saturday 19.10., the day of astronomy, we will open from 8 pm, also assuming clear skies. Furthermore, two lectures will be offered on Wednesday, October 16 and 23 in the Audimax of Zweibrücken University of Applied Sciences. For more details see point Events.

Sun and moon

On the last Sunday of the month, which this year is October 29, the clocks are set back by one hour at 3 a.m. to 2 a.m., the regular Central European Time.

The full moon will affect the observation of fainter objects around the days of October 17.

Planets

The innermost planet Mercury is close to the sun, so we will not be able to observe it this month.

Venus as an evening star is not yet particularly conspicuous. After sunset, it can be observed low in the southwest. On the evening of October 5, the narrow waxing crescent moon passes about three degrees south of it. However, a clear view of the horizon is essential.

Mars shifts its rises to the time before midnight. However, it is still quite inconspicuous.

Saturn was in opposition to the Sun at the beginning of the previous month and still offers a good observation opportunity in the first half of the night. After dark, it can be found high in the east at the beginning of the month and towards the south towards the end of the month. As already mentioned, the ring aperture is only 4 degrees, a far cry from the maximum of 27 degrees.

Uranus and Neptuneboth exclusively objects for telescopes, can be observed throughout the night. However, one should not expect too much when looking through a telescope, both have an apparent diameter of only a few arc seconds.

Starry sky

The summer starry sky has almost completely receded. High in the east, the autumn quadrilateral, the winged horse Pegasus, can already be seen. Its origins as a hybrid creature are probably oriental. It was frequently depicted in Cretan and Asia Minor art and even on the reverse of Roman coins up until the third century AD. A little further to the east is an object that is already impressive in binoculars, our neighboring galaxy, the Andromeda Nebula with the designation M32.

The following graphic shows the view of the sky on October 15 at 11 pm.

Partial lunar eclipse, equinox, Saturn in opposition.
Starting this month, we will be opening our observatory again on Friday evenings, provided the night sky is clear, as we have already mentioned several times. In September from 9 pm, October from 8 pm and November to February from 7 pm. March and April from 8 and 9 pm respectively. Only at these times will the evening sky be dark enough for astronomical observations.

Sun and moon

We are fast approaching the fall. On September 1, the sun sets in Zweibrücken at 8:16 pm, on September 30 at 7:14 pm. At the time of Autumn equinox On the 22nd at 14:22, the sun will cross the celestial equator in a southerly direction and the nights will once again be longer than the days. The maximum height of the sun above the horizon is still 40.75 degrees.

On 18.9. a partial lunar eclipsewhich reaches its peak in the morning hours at 4:44 am. However, this is quite modest, covering only a good 9 percent of the lunar disk.
Here is a graphical representation.

The full moon will affect the observation of fainter objects around the days of September 18 this month.

Planets

Mercury offers an acceptable observation opportunity in the morning sky in the first third of the month. It can be seen about half an hour before sunrise on the east-northeastern horizon.

Venus is slow to assert itself in the evening sky due to its declining declination (height above the celestial equator at 40.75 degrees in Zweibrücken). It sets at 20:38 in the middle of the month. Sunset occurs at 19:46. On September 5, there is an opportunity to observe the narrow crescent moon right next to Venus.

Mars continues to rise early, but remains an object of the second half of the night. It will not reach its peak until next year.

The rise of the Jupiters occurs before midnight. On September 15, it rises above the horizon at 11:09 pm. Here, too, we will have to be a little patient as it will not be in opposition to the sun until the beginning of November.

On 8.9. Saturn in opposition to the Sun. It is already above the eastern horizon at nightfall.
If we look through a telescope, we will immediately notice the narrow ring. There is hardly a trace of the magnificent ring that we know from photographs and observations in recent years.
The maximum ring opening is up to 27 degrees, but we look at its edge every 14.75 years. This will be the case for a few weeks in March 2025. The ring is only up to a few hundred meters thick. It is therefore not visible from Earth when looking at its edge.
Fun fact: If we could produce a razor blade with the surface of the rings, the rings would clearly be "sharper".

Uranus can be seen with the naked eye under the best conditions and could therefore have been perceived by the ancient Greeks. However, it was not discovered until March 13, 1781 by the German-British astronomer Wilhelm (William) Herschel. Uranus rises in the evening and reaches its opposition in mid-November.

Neptune is roughly in line with the Earth and the Sun (opposition position) on the night of September 20-21. At this time, its distance is 4.322 billion kilometers, which corresponds to around 29.89 astronomical units (mean distance Earth-Sun). It is purely an object for telescopes.

Starry sky

The summer triangle has already shifted noticeably to the west. The autumnal quadrilateral, consisting of four bright stars of Pegasus, is already making itself felt in the eastern sky. In darker areas, the shimmering band of the Milky Way can still be seen high above us to the west on moonless nights. Sometimes even from the observatory.

One object for binoculars is the magnificent globular star cluster M13 in faint Hercules, which can still be seen in the western sky in the evening this month. It is located between the constellations of the Swan and the near-horizon Bear's Keeper or Bootes.

The following graphic shows the view of the sky on September 15 at 11 pm.

Perseids and Saturn occultation: Every year in August, countless shooting stars, the Perseids, can be observed. They get their name from their origin in the direction of the constellation Perseus, which slowly rises above the eastern horizon during the month. This year, the maximum of up to 25 star clusters per hour is expected between the evening of August 12 and the morning of August 13. It is not uncommon to see so-called fireballs or bolides with a brightness comparable to the brightest stars. The Perseids originate from a cloud of dust particles left behind by the comet Swift-Tuttle, which was discovered in July 1862 on its 133-year journey around the sun.

On the occasion of the maximum of the Perseids, our observatory opens on Friday, August 9th, Saturday, August 10th and Sunday, August 11th from 9 pm, weather permitting. See also the point Events.

As Meteoride are small objects in space that are created, for example, by collisions of asteroids or eruptions from comets. If these enter the earth's atmosphere, they become a meteor or shooting star. When they reach the Earth's surface, they are called meteors.te. Meteorites from the moon and Mars have also been detected. Just over a year ago, a meteorite fall took place in Elmshorn, see Elmshorn (meteorite) - Wikipedia.

SUN AND MOON

As every year, August shows us the most beautiful starry sky in summer. The sunsets in Zweibrücken continue to be earlier from 21:08 at the beginning of the month to 20:13 on the 31st of the month.
At the time of the maximum of the Perseids, the moon is in the first quarter. Already quite low in the sky, it leaves the celestial stage at around 11:34 pm, with astronomical twilight ending at 11:05 pm. The conditions are therefore pretty good, provided the weather cooperates.

PLANETS

The fast-moving planet in the sky Mercury cannot free itself from the Sun's rays in August, it remains unobservable to us. The encounter with Venus on the 6th of the month also remains hidden from us for this reason.

The still almost fully illuminated Venus disk with a diameter of only around 10 seconds of arc, only gradually becomes noticeable in the evening sky. The reason for this is that the declination of Venus, and therefore its diurnal arc, decreases daily, causing it to set earlier and earlier over the course of the month. However, the sun also sets earlier.

Mars and Jupiter dominate the second half of the night. On the night of the 15th, Mars passes Jupiter about 0.3 degrees to the north.

Saturn is a highlight of this month alongside the Perseids. Although it only reaches its opposition position at the end of the first third of September, on the 21st of the month there is a Rare occultation of Saturn by the moon. The overcast begins in Zweibrücken at 5:30 in the morning, when nautical twilight has already set in. Here is a graphic representation:

Uranus can only be seen in the morning sky with the aid of a telescope.

Neptune is approaching its opposition position, which it will not reach until the last third of September. A telescope is required to observe it.

STARRY SKY

August is the month with the most beautiful starry sky in summer par excellence.

About us the band of the Milky Way with countless stars and the summer triangle is now revealed in its full splendor in less light-polluted areas.

This month there is no detailed description of the starry sky, this can still be seen from the July or the august from last year. Instead, an invitation to simply lie down on a meadow with a lounger or blanket and a pair of binoculars and enjoy the summer night sky. Also in front of our observatory. If it is open despite the summer break, you are welcome to visit us. Don't forget a jacket, it can get quite chilly at night.

Here is the course of the Milky Way on August 15 at 0:00 a.m. each year. East is on the left, south at the bottom.

The following sky view is valid for August 1 at 0:00 am, August 15 at 11:00 pm and August 30 at 10:00 pm.

SUN AND MOON

On the 20th of the previous month, the sun reached its highest point in the sky at noon and is now sinking again. The length of the day in Zweibrücken decreases from 16 hours 17 minutes to 15 hours 17 minutes over the course of the month. From July 5, we again reach the point at which it becomes dark enough for astronomical observations. Even if only at 1:20 a.m. for a whole 15 minutes. During these few minutes, the sun already reaches a position of more than 18 degrees below the horizon, which is considered night for amateur astronomers. Also on the morning of July 5 at 5:00 a.m., the earth is at its furthest point from the sun. The distance at this time is 152,100,000 kilometers.
On the 21st of the month, the full moon makes it difficult to observe fainter objects. In the night from July 24 to 25, our Earth companion apparently visits the planet Saturn. At 1:00 a.m., the angular distance is just under 2 degrees, i.e. almost four full moon diameters.

PLANETS

The first planets reappear in the night sky.

Mercury reaches its almost maximum possible eastern angular distance from the sun on July 22 at just under 27 degrees. The large angular distance is due to the fact that five days later it is at its furthest point from the sun at a distance of almost 70 million kilometers. Unfortunately, this is not sufficient for evening visibility as it is too far south of the Sun's apparent orbit around the Earth (ecliptic).

Venus was at an upper conjunction to the Sun on 04.06.2023. The angle to the sun of almost 15 degrees is not yet sufficient for evening visibility. In August, it is possible to find it low in the evening sky.

Mars increases its morning visibility considerably and reaches the northern parts of the zodiac. On the first of the month, it crosses the horizon line in Zweibrücken at 2:23 a.m. and continues to rise early to 1:21 a.m. at the end of the month.

Jupiter can be observed in the morning sky. It rises at 1:47 a.m. on the last day of the month. However, it does not reach its peak with the opposition until the beginning of December.

From the middle of the month, the planet Uranus the object of observation in the second half of the night.

Neptune begins its opposition loop, but still poses a challenge in the morning sky. A telescope is required to observe both planets, Uranus and Neptune, as they can never be seen with the naked eye.

Formerly the ninth planet and now belonging to the minor planets Pluto is at opposition to the sun on July 23. However, it can only be observed in larger telescopes, such as those at observatories.

STARRY SKY

Deep in the East the winged horse of antiquity, Pegasus, stretches its head above the layers of haze near the horizon.

Just above the Southern horizon Scorpio and Sagittarius are still in the sky. They are only significantly higher in the night sky in the Mediterranean regions.

A little further to West the inconspicuous constellation of the Northern Crown and Bootes can still be observed. As already here experts expect a nova to appear by September 2024.

The summer triangle with Vega, Atair and Deneb is approaching from the east. Zenith.

High above us Hercules and the inconspicuous dragon still stand.

The big bear is already sinking on northern night sky towards the west. Opposite Polaris, as seen from the Great Bear, the "celestial W", Cassiopeia, slowly rises into the northern regions.

The following sky view is valid for July 1 at 0 am, July 15 at 11 pm and July 30 at 10 pm.