Astronomical event: planetary alignment of February 28, 2025
The last week of February will offer us an astronomical spectacle worthy of admiration: the planetary alignment in which the seven visible planets of our solar system will line up in the form of an arc over the horizon after sunset. A rare event that will allow us to see Mercury, Venus, Mars, Jupiter and Saturn with the naked eye, while Uranus and Neptune will be accessible with telescopes .
A rare planetary alignment
This phenomenon, which will take place between February 22 and 28, will be one of the few opportunities of the year to simultaneously observe all the planets of the solar system in the Earth's sky. For the most attentive observers, it will be essential to have a clear sky and an unobstructed horizon in order not to miss the appearance of the faintest stars, such as Mercury and Saturn, which will be very low in the west.
Venus and Jupiter, two of the brightest planets, will dominate the celestial scene, standing out in the constellations of Pisces and Taurus respectively. Mars, with its characteristic reddish glow, will be visible higher in the sky, in the constellation of Gemini. Mercury, on the other hand, will be the most difficult to detect, due to its proximity to the Sun and its low elevation above the horizon.
It is important to note that alignment is only a perspective from our planet, alignment does not occur symmetrically as many think.
Observation times for the alignment in Spain and Mexico
For those wishing to observe this event from Spain, the best time will be approximately 45 minutes after sunset, that is, around 19:45 (peninsular and Balearic time). It is important to have a clear horizon to the west in order to be able to distinguish Mercury and Saturn before they disappear behind the horizon line.
In Mexico, visibility will also begin about 45 minutes after sunset, which varies depending on the location within the country. In Mexico City, for example, the best time to observe will be around 7:10 p.m. (local time), while in the northwest of the country, such as in Tijuana, it will occur around 6:20 p.m. (local time). As in Spain, an unobstructed horizon will be key to making the most of the observation.
The importance of the ecliptic
The planetary parade will follow the ecliptic, the imaginary line along which the planets move in their orbit around the Sun. This line crosses the constellations and is also the path along which eclipses occur. The minimal inclination of the planetary orbits with respect to that of the Earth means that, on special occasions such as this, all the planets will be visible in almost the same region of the night sky.
Uranus and Neptune: the hidden giants
While the five classical planets will be observable without instruments, Uranus and Neptune will require telescopes to detect them. These ice giants, located 2.955 and 4.620 billion kilometres from Earth respectively, are too faint to be seen with the naked eye. Uranus, discovered in 1781, and Neptune, in 1845, remained hidden from humanity until the modern era due to their remoteness and reduced brightness.
The great conjunction of March 1st
The astronomical event will culminate in a beautiful conjunction on March 1, when the crescent Moon will be positioned between Venus and Mercury on the western horizon. This celestial encounter will provide a spectacular sight, with the thin curve of the Moon illuminated next to the two innermost planets of the solar system. For those who wish to observe it, the best time will be shortly after sunset, looking towards the west.
Planetary alignment: A spectacle to remember
This planetary parade will remind us of the grandeur of the cosmos and our connection with the stars. Although winter is giving way to spring and the nights are getting shorter, we can still enjoy the celestial dance and the immensity of the universe from our little corner on Earth. Let us take advantage of every opportunity to look up at the sky and marvel at the secrets that the firmament holds.