A total solar eclipse is one of the rarest and most spectacular astronomical phenomena observable from Earth. Although a total solar eclipse occurs somewhere on the planet approximately once every 18 months, it may not be seen again at a particular location for several generations. The last total solar eclipse visible in Latvia occurred on 30 June 1954, while the next is not expected until 25 May 2142. Weather conditions in the Baltic region are also often unfavourable for astronomical observations, as cloudy skies frequently prevent even significant celestial events from being observed. For this reason, astronomy enthusiasts and researchers often organise expeditions to locations where the path of totality coincides with a greater likelihood of clear skies.

The possibility of a total solar eclipse is the result of an extraordinary cosmic coincidence. Although the Sun is approximately 400 times larger than the Moon, it is also about 400 times farther away from Earth. As a result, both celestial bodies appear almost the same size in the sky. This allows the Moon to cover the solar disc with remarkable precision, revealing structures in the Sun's atmosphere that are normally impossible to observe due to the Sun's intense brightness.

Earth is not the only place where such a remarkable alignment of celestial bodies can occur naturally. Jupiter's four largest moons can cast shadows on the planet's surface, producing eclipse-like phenomena. Moreover, the moons Io, Callisto and Ganymede have simultaneously crossed Jupiter's disc between the Sun and Jupiter, creating a triple transit, or triple eclipse phenomenon.

Observers located on certain moons of Jupiter or Saturn could experience spectacular eclipses caused by other moons. Similar events may also be possible in distant exoplanetary systems if a moon and its star appear approximately the same size in the sky to an observer. Such cosmic coincidences may be rare, but they are not unique to Earth.

Why We Do Not See a Solar Eclipse Every Month

The Moon orbits Earth approximately once a month, so it might seem logical to expect solar eclipses to occur regularly. However, total solar eclipses are rare at any particular location. The reason lies in geometry.

The Moon's orbit is tilted by approximately five degrees relative to the plane of Earth's orbit around the Sun. Most of the time, as seen from Earth, the Moon passes either above or below the Sun. Only when the orbital planes and the positions of the celestial bodies align precisely can the Moon cast its shadow on Earth and cause a solar eclipse.

This complex alignment makes every total solar eclipse a special event, attracting scientists, photographers, educators and astronomy enthusiasts from around the world.

One of the main objectives of STEM education is to encourage young people to pursue studies and careers in science, technology, engineering and mathematics. Astronomy is a particularly powerful tool for achieving this goal, as it naturally combines physics, mathematics, engineering, computer science and curiosity about the Universe.

A total solar eclipse provides a unique educational experience, transforming knowledge acquired from textbooks into something tangible and memorable. Concepts such as the motion of celestial bodies, celestial mechanics and solar physics suddenly become visible above our heads.

For the students from Ventspils, this trip was a vivid demonstration that science is not confined to classrooms or laboratories. It is an international field driven by collaboration, observation and discovery.

Photo: V. Bezrukovs, J. A. Cázares Montes, A. Kalniņa.