The starry sky in June 2025
Mercury in the evening sky, Summer solstice
Due to the short nights, the observatory will remain closed at night in June. However, a few Sundays are planned on which the observatory will open between 14:00 and 16:00 for solar observation. The dates cannot be planned in advance due to the weather. The times will be announced via a ticker on our main page.
SUN AND MOON
The longest day of the year 2025 is on June 21. At 04:42, the sun reaches its greatest northern latitude due to the tilt of the earth's axis by 23.45 degrees. At 13:32 on this day, the sun is 64.18 degrees above the horizon in Zweibrücken. The length of the day is 16 hours and 23 minutes. From an astronomical point of view, it is no longer really dark at our latitude. Astronomical night only falls when the sun is lower than 18 degrees below the horizon. This is not the case between June 7 and July 4. We can look forward to long, bright days and, due to the full moon on June 11, brighter nights. However, the full moon in summer does not appear quite as bright as in winter. Its maximum height on this night is only 12.3 degrees.
PLANETS
The evening sky is poor in planets.
Mercury can be observed in the evening sky for the second and last time this year in the last half of the month. Its best observation days are between June 19 and 27.
Here is the view of the sky at 22:15 from the observatory hill.
Venus reaches its greatest angular distance from the sun on the 1st of the month at just over 45 degrees. It therefore dominates the eastern morning sky with its brilliance.
The red planet Mars is receding further from the evening sky. It is no longer an attractive object for visual and telescopic observation. On the evening of the 17th, it passes by Regulus, the main star of Leo, by only 0.8 degrees.
The giant planet Jupiter has withdrawn completely from the evening sky. It will gradually reappear in the morning sky in mid-July.
Saturn can be observed in the morning sky. The ring of the gas planet shows only a small aperture in the telescope.
Uranus was in conjunction with the Sun in the middle of the previous month and therefore cannot be observed.
Neptune is not yet a worthwhile object in the morning sky.
STARRY SKY
In the East the summer constellations have already risen. Among them are the Swan with the star Deneb, the Eagle with the main star Atair, which is still close to the horizon, and Lyra with its bright star Vega, which is also the brightest star in the northern sky. This means that the summer triangle, which consists of the three stars mentioned above, is completely above the horizon, even if it is not yet too high.
Deep in the South is Scorpio with its main star Antares, which means "opposite Mars". Because of its reddish color, it has already been confused with Mars, which is also reddish. The bright star to the west of Scorpio is Spica, the main star of Virgo.
The lion is already approaching the western horizon. Cancer is already on the verge of extinction.
High above us the inconspicuous constellation of Hercules can be seen. A little further to the southwest is the equally inconspicuous constellation of the Northern Crown and Bootes, which has also been called an ice cream cone because of its shape.
Low on the Northern sky the "celestial W" is Cassiopeia, wife of Cepheus, who can be found a little further west.
The following sky view is valid for June 1 at midnight, June 15 at 11 p.m. and June 30 at 10 p.m.
