- A solar eclipse occurs when the Moon passes between the Sun and the Earth, aligning during the new moon phase.
- There are three main variants: total, annular and partial, depending on the alignment and orbital distance.
- For safe observation, the use of ISO 12312-2 certified filters or indirect projection methods is essential.
- Spain is preparing for an exceptional cycle of astronomical events known as the trio of eclipses.
You've probably been awestruck at some point, thinking about that moment when day turns to night in a matter of minutes. A solar eclipse is, essentially, a cosmic play of shadows where the Moon passes directly between the Sun and the Earth, blocking the sunlight and giving us a visual spectacle that always leaves people speechless.
For this to happen, it's not enough for it to be a new moon; the Sun, the Moon, and our planet need to be perfectly aligned . Because the lunar orbit is slightly inclined (about 5,24 degrees) with respect to the ecliptic, the Moon's shadow usually passes above or below the Earth, so these events don't occur every month, but are much more selective phenomena.
Types of eclipses and their particularities
Not all eclipses are the same, and that's where the magic of astronomy comes in. Depending on your location and the distance of the Moon, you'll see very different things. A partial eclipse is the most common, where the Moon only covers part of the solar disk, leaving the Sun looking like a bitten cookie.
Then we have the total eclipse , which is the crown jewel. In this case, the Moon completely covers the Sun from a narrow strip called the path of totality. This is where the most amazing thing happens: the sky darkens, temperatures drop, and you can see the solar corona , that outer atmosphere that is normally invisible.
Finally, there is the annular eclipse . This occurs when the Moon is at its farthest point from the Sun (apogee) and its apparent size is smaller than that of the Sun. The result is a spectacular ring of bright fire surrounding the dark silhouette of our satellite.
The science behind the phenomenon
For an eclipse to occur, the Moon must be near its nodes, which are the points where its orbit intersects the Earth's plane. Interestingly, there are at least two solar eclipses each year, although on special occasions there can be up to five in a single year if the first one occurs very close to January.
There is also a cycle called the Saros period , which lasts about 18 years and 11 days. This cycle allows astronomers to predict with astonishing accuracy when and where a very similar eclipse will occur again, since it is a common multiple of lunar revolutions.
Throughout history, these events have been interpreted in countless ways. From the ancient Chinese who saw them as omens, to the famous eclipse of Thales in 585 BC, which, according to Herodotus, was so impactful that it caused two armies to stop fighting and sign a peace treaty in the middle of battle.
How to look at the Sun without going blind
This is where we need to get serious: looking directly at the sun is a terrible idea that can cause irreversible retinal burns . Regular sunglasses, X-rays, and even glass tinted with candles are useless. The only safe option is ISO 12312-2 certified sunglasses or professional sun filters.
If you don't have specialized equipment, you can resort to indirect observation . A very simple technique is to poke a small hole in a piece of cardboard and project sunlight onto a sheet of paper. You can also take advantage of the light that filters through the leaves of trees, which creates small images of the eclipse on the ground.
- Use of telescopes: Always project the image onto a smooth surface; never look through the eyepiece without a filter.
- Binoculars: Never use them to look directly at the Sun, as they concentrate radiation and the damage is instantaneous.
- Photographer: It is essential to install the filter. in front of the target and not behind the eyepiece to prevent the glass from shattering due to the heat.
The highly anticipated event in Spain and the Trio of Eclipses
Spain is preparing for an unforgettable experience. On August 12, 2026, a large part of the northern half of the Iberian Peninsula will be able to enjoy a total solar eclipse . From Galicia to the Balearic Islands, darkness will envelop the landscape just before sunset, creating a mystical and captivating atmosphere.
This event marks the beginning of what is known as the Trio of Eclipses , a sequence of phenomena that includes another total eclipse on August 2, 2027, and an annular eclipse in January 2028. It presents a golden opportunity for scientific tourism and astronomical outreach in our country.
To manage such logistical chaos, the government has created the Interministerial Commission for the Trio of Eclipses. Its objective is to coordinate mobility and security, preventing road gridlock and ensuring that everyone can enjoy the spectacle without endangering their own health or the health of others.
The combination of planetary alignment, the use of appropriate eye protection, and planning for upcoming events on Iberian soil makes these phenomena an educational and exciting experience. Understanding celestial mechanics and respecting safety regulations is the only way to marvel at the temporary darkness of the day and the majesty of the solar corona.
