The brothers dress up
High above our heads is the famous couple Castor and Pollux. They are the brightest stars of Gemini and something of a step-sibling at best.
The winter constellations have already moved deep west on the March evenings, but still hold the position as the brightest constellations, especially Orion and the Great Dog ("Canis Maior", CMa). They have already disappeared on our nocturnal overview map. But the last major constellation of the cold season is still high in the west and attracts our attention not only because of its brightness, but also because of its shape: Gemini ("Gemini", Gem).
Castor and Pollux are the names of half-siblings from Greek mythology. They are the namesake of the two brightest stars in this constellation. The two stars are only four and a half degrees apart. The lighter, more southern of the two is the orange Pollux. Kastor, on the other hand, glows white and, when viewed through a telescope, turns out to be a very close binary. The magnitudes of the two are 1.1 and 1.6 mag. The following applies here: the higher the numerical value, the weaker the star shines in the night sky. The decimal place is often left out, and everything that is brighter than 1.5th magnitude is called a star of the 1st magnitude. So it is that Castor and Pollux, although they are also called "twin stars", do not even belong to the same size class. The overview card shows the twins as stick figures standing side by side.
For fun, transfer the lines to the photo below on the left. Just outside of Kastor's slightly pendulous foot is M35, a large, bright star cluster. When viewed through a telescope at low magnification, it covers almost the entire field of view. The next constellation to the east is the famous but inconspicuous Cancer ("Cancer", Cnc). It's fairly easy to find these days because it's graced by the ringed planet Saturn. The crab is especially famous for M 44, also called "Praesepe" or beehive heap. You can see this as a blurry spot with the naked eye on a clear, moonless night, far from urban light pollution. Point your binoculars at it!
Following the zodiac is the lion ("Leo"), found high up in the south on the general maps. By appearing, he announces the approaching beginning of spring. Another sign of this is that the Big Dipper is directly overhead.
Planets in March
Mercury sets at the beginning of the month as a crescent soon after the Sun. It will overtake Earth on its inner orbit around the Sun, and will roam around at dawn for two months beginning in late March.
Saturn you can marvel at the night sky until the early hours of the morning. With its rings and moons, it offers an ideal target for observations with a telescope. It is less than two and a half degrees west of M 44, which is about the width of two fingers at an outstretched arm.
Mars can be found at dusk high in the west in the constellation Taurus ("Taurus"). However, its brightness decreases quickly, so that the equally reddish Aldebaran surpasses it. Lastly, the Red Planet stands to the east of Taurus, almost exactly between the stars that mark the tips of the horns.
Jupiter rises at 10:30 p.m. in early March. It shines in Libra ("Libra"), not far from its brightest star, Zuben Elgenubi (Alpha Librae).
Venus is low in the southeast during dawn. On March 25th it reaches its greatest elongation, the maximum angular distance from the sun. With a telescope you can watch it go through its "half-Venus phase" and be exactly half illuminated by the sun.
The Moon will be to the right of Mars on the evening of the 5th and to the left of Saturn on the 10th of March. On the night of the 14th to the 15th we can observe a lunar eclipse. The satellite enters the earth's penumbra at around 10:23 p.m. It stays there until 3.10 a.m., but never reaches the umbra and is therefore not darkened as much as in a total lunar eclipse. The waning gibbous moon rises to the right of Jupiter at around 10:30 pm on March 18 and well below Venus' left at dawn on the 26th.
The Sun reaches the equinox on March 20 at 7:26 p.m. This marks the beginning of spring in the northern hemisphere. An exceptionally long total solar eclipse can be admired on March 29th. In Central Europe, the coverage is around forty percent. © astronomy today