A partial solar eclipse will occur on Saturday 29 March 2025

On Saturday 29 March 2025 there will be a solar eclipse observable from central Europe. It will only be partial, but will be accompanied by very favourable viewing conditions. The Czech Republic will be at the edge of the zone of the phenomenon, which will be observable in northeastern America, virtually all of Europe and parts of Asia. In our territory, the eclipse will be visible around noon at an altitude of more than 40° above the horizon, and at its maximum phase the Moon will be occulted up to 22 percent of the diameter of the solar disk (northwestern Bohemia).

How does a solar eclipse occur?

The solar eclipse occurs at the momentwhen the Moon is in the new phase between the observer and the Sun, partially or completely obscuring the Sun's disc. Because the Moon orbits our planet in an orbit slightly inclined to the plane of the Earth's orbit (the deviation is about 5°), more often than not the Moon in the nova phase will miss the solar disk in the daytime sky and no eclipse will occur. Only about once every six months or so does the New Moon come very close to the imaginary straight line between the Earth and the Sun in its orbit, and some people on Earth can observe this phenomenon.

The farther the observer is from the conical shadow of the Moon, the smaller percentage of the Sun is obscured during the phenomenon. The area of visibility of a partial eclipse never covers the entire hemisphere of the Earth where the day is, and thus a partial eclipse is not visible everywhere during a particular event. V in the event of an eclipse on March 29, 2025 it is only a partial eclipse, the full moon's shadow does not reach the Earth's surface anywhere. The eclipse will be most pronounced in Canada, with a 94.8 per cent partial eclipse in northern Quebec.

How will the March 29 solar eclipse take place?

The phenomenon will start around 11:29 CET (the start time varies in minutes in different places). At that time, the silhouette of the dark New Moon will begin to "bite" into the solar disk from the right edge. The further east you are, the later the partial eclipse will start and the smaller the eclipse will be. The maximum of the phenomenon will occur between 12:15 and 12:23 CET, depending on the observer's position. It ends around 1 pm, also depending on the position of the observer. The sun will be very high above the southern horizon throughout the whole phenomenon.

Below is a table with the visibility of the phenomenon in selected Czech cities. For details about the phenomenon in your chosen location, just visit interactive map by Xavier Jubier and choose your location on the map. For observation, it is necessary to equip yourself with a special filter for eye protection (see below). For more detailed information about this phenomenon and other solar eclipses to come in the next few years, see also the book Mysterious eclipses.

Visibility of the solar eclipse on March 29, 2025. Cities are ordered from west to east. Times are in CET.

Solar eclipse viewing safety

When observing solar eclipses, but also sunspots or other phenomena associated with a direct view of the Sun, it is absolutely necessary to follow the safety rules. Looking directly at the Sun, even if it is partially obscured by the Moon, can cause serious or even permanent eye damage. In general, there are several methods to observe the Sun indirectly (by projection, live video streaming, etc.). Direct observation - with the naked eye or binoculars - always requires the use of a suitable filter. Below is a list of possible and available filters that can dim the sunlight and allow you to observe the phenomenon safely:

• Special glasses or foils from Baader Planetarium: the foil and the glasses can be purchased from the company SUPRA Prague.
• Welding filter grade 14 and higher: The filter generally used for welding metal joints is usually reliable even when using a higher degree of solar tracking.
• Any glasses or filters purchased at the nearest observatory: Observatory staff are aware of the risks involved in observing the Sun, so they will undoubtedly offer you safe equipment (if it is in the observatory's range). In general, be suspicious of street vendors selling glasses and get them from the professionals.

Public viewing of the solar eclipse on 29 March 2025

Many observatories will offer observations of the phenomenon with large observing telescopes with a filter, weather permitting. For those who would like to observe the phenomenon with expert commentary and a large telescope, there is a list of events to the eclipse on the website of the Czech Astronomical Society.

Interesting facts at the end

Coincidentally, there was already one solar eclipse on the same date in this century on our territory. It occurred on March 29, 2006 and was observed as complete by many domestic enthusiasts and professional astronomers, especially in Turkey and Libya. In central Europe it was observable as a partial of about 50 %.

You don't need a telescope to see a partial solar eclipse - just a tree. Indeed - if you are near a tree with a lumpy crown, a large number of small images of the Sun will be visible in its shadow due to the so-called pinhole effect. If there is no tree nearby, just leave your clenched fist slightly open and let the sunlight through it to the shadow of your fist on the ground. A small disc of light will be "bitten off" just like the sun's disk in the sky. The phenomenon is called camera obscura and simply get you can make and a more sophisticated eclipse-viewing instrument based on this principle.

The next solar eclipse we will see from the Czech Republic will take place next year on August 12, 2026 and will be the largest partial eclipse visible in Central Europe until July 13, 2075. Those who go to see it Spain, they will see it as a complete. It will also be the closest total solar eclipse to the countries of Central Europe until 2081.

Czech Astronomical Society/ gnews.cz - RoZ