Night sky observation - March

Little Constellation

Do you like science and science fiction? If so, you will certainly be interested in the universe and you will want to live it every day to fill your brains with knowledge and your hearts with desire cognition and discovery unavailable. This article presents the most interesting things we can with the naked eye without binoculars observe the night sky. A cold and rainy moon in The sign of Pisces begins the first part of our humble knowledge of the universe!

A compass may be suitable for orientation in space from the point of view of the sides of the world. You can also use a standard hunting telescope. More interested individuals can also purchase a real astronomical telescope. However, everyone has little free time, so that we can observe the stars early in the morning on the way to work or in the evening on the way from the pub, our simple eyes will suffice.

The merchant god Mercurius and his planet ☿

The March night sky this year offers great conditions for observing this moon-like body. Mercury is only about half the size of the Moon, made up of 70 % metals (iron, nickel) and 30 % silicates. Thanks to the contained metals, it is the second densest planet in the system, the first being the Earth. Mercury has a considerable amount of iron accumulated in the core, which makes up to 42 % of the planet's volume. For Earth, it is only 17 %. The nucleus is probably liquid and, based on the dynamo principle, generates a magnetic field of 1 % of the Earth's nucleus.

We can see Mercury in the evening over the western horizon before it falls beyond the horizon. It is accompanied by the planet Venus, which is much brighter. If you don't see it, you can sense it just above Venus slightly to the right. Venus Mercury will probably lighten. Večernice or Jitřenka is also the 4th brightest object that can be observed in the sky. The first is the Sun, followed by the Moon, the third the satellites Iridium, the fifth is the International Space Station (also known as ISS), followed by Mars, Jupiter and then the stars: 8. Sirius, 9. Canopus, 10. Alpha Centauri .

Interesting things will happen to Mercury on the evening of March 15. On this day, at exactly 4 pm, Mercury reaches its greatest eastern elongation. Eastern elongation means that the planet sets just after dusk and is half lit by the sun.

From the planets of our system, we can enjoy the view of Mars and Saturn early in the morning (before six). Both fly over the SE horizon, Saturn on the left, more orange Mars on the right.

No need for a small car and compasses

As the Earth tilts during the year, it gradually reveals other parts of the Milky Way and the cosmos in the sky. The constellations that we see in our latitude throughout the year are called circumpolar. So these constellations never fall beyond the horizon and would be visible even during the day if they were not illuminated by the Sun. The circumpolar constellations of the northern sky are: Ursa Major, Ursa Major, Cassiopeia, Dragon, Cephusus, and Giraffe.

In this introductory part, for a start, we will analyze the constellations that shine for Europeans all year round and we popularly call it the Little Car. The constellation of the Little Bear, or its asterism of the Little Wagon, has been used by mankind for many centuries for orientation in the landscape or at sea. (Asterism is a distinctive group of stars in the sky, but it is not one of the 88 official constellations.)

The brightest star of this constellation shines on the imaginary handle of a car or at the end of a bear's tail, and in Latin it is called Polaris. The earth's axis passes through the polar and delineates the north celestial pole, which at the same time always points north. However, this was not always the case. The position of the North Celestial Pole changes due to the precessional motion of the Earth's axis, or the deflection of the Earth's axis, due to the attraction of nearby cosmic bodies such as the Sun or the Moon. The closest to the North Celestial Pole will be the Polaris around 2100. 2000 years ago, for example, the pole was more between the Polaris and the last tail star in the constellation of the Dragon, Giausar.

The polar bear is located approximately 432 light-years from Earth. It is also the brightest Cepheid visible on Earth. (Cepheid is a pulsating variable star. Pulsation is caused by the regular shrinkage and expansion of its subsurface layers. Due to the well-known relationship between pulse period and absolute luminosity, Cepheids are used as standard candles to determine the distances of galaxies and globular clusters. the size of the cepheid, then we get its distance.)

A polar star is a multiple star, meaning that it can consist of two or more stars bound together by gravity. The main star is a yellow and white giant 6 times heavier than the Sun, 45 times larger and 45,000 times brighter.


The second brightest star of the Little Car is Kochab. This orange giant forms the front wheel of an imaginary Small Car. 131 light-years away. Kochab has probably depleted his hydrogen reserves and started burning helium, meaning that he has left the group of stars in the main sequence that are still going on hydrogen. Kochab also contains a large amount of barium.

The front edge of the car is represented by the third brightest star Pherkad. The pulsating Pherkad is located at a similar distance as the Polar Bear and is also used as a standard candle in astronomy.

March constellations

Constellations that are not circumpolar treat over the course of the year and re-emerge above the horizon. In March, the constellations of Cancer, Leo, Little Lion, and Sextant move above the horizon.

In the evening above the SE horizon we can see the star Regulus from the constellation Leo. The part of the constellation that has the shape of an inverted question mark will help us find this constellation in the sky, and it is the star Regulus that forms the imaginary dot. Regulus is a four-star star only 77 light-years away. Together with the stars Antares (constellation Scorpio), Fomalhaut (constellation Southern Fish) and Aldebaran (constellation Taurus), he was one of the stars that divided the year into four seasons (Aldebaran - winter, Regulus - spring, Antares - summer, Fomalhaut - autumn). .

Above the SW horizon we can still see the most characteristic constellation of the winter sky, Orion, with the typical three stars forming Orion's belt. (Orion has the shape of a man's body, that is, a waist, shoulders, head, and legs.)

Home planetarium

The useful computer program Stellarium will help us to observe the night sky more inquisitively. It is a computer planetarium that displays a realistic 3D sky as you can see it from your location. The program for the computer is free and you can download it directly on the official website of the manufacturer with the incorporated Czech, only the mobile version is charged.

Stellarium is very easy to use. In addition to the already mentioned adjustability of your current position, you can also adjust your view depending on the light pollution, or you can completely remove the pollution and the atmosphere and see all the space objects. Icons on the clear taskbar allow instant display of constellation shapes and drawings, descriptions of all bodies from satellites to exoplanets, orbits of planets and satellites or current meteor showers.

It is also possible to control the time. You choose either the current elapsed time, you can stop it, you can go back 10,000 years in history or 5,000 years into the future as you like. The program calculates the motion of cosmic bodies and determines their location at a given age. The shapes of the actual constellations as we know them today will disintegrate due to the motion of the stars.

You can also focus on individual objects and zoom in on them. For example, the planets of our system can be explored. You get closer to Saturn and you also see all its moons.

As for the constellations, you can choose a total of 14 different stellar mythologies. If you have this option active, the drawings overlapping the shapes of the constellations will change, and the European constellation Hare will become the Chinese constellation Toilet and Screen. And the Big Dipper will become the Northern Ladle. The program also includes mythological information.

You can also turn on the equatorial grid, which is suitable for subsequent orientation in the night sky. The Earth's axis passes through the North Pole and is always inclined to the north.