The summer of 2019 begins, in the northern hemisphere, on June 21 at 5:54 p.m. peninsular time, as calculated by the National Astronomical Observatory. In the northern hemisphere, the summer solstice always occurs between June 20 and 22.
The hottest season of the year will last exactly 93 days and 15 hours , ending on September 23 with the autumnal equinox.
The day of the beginning of summer is also the longest day of the year: the Sun rises earlier and the one on which it sets later. It is the summer solstice (still sun) , a name that has its origin in the behavior of our planet in relation to its position and inclination with respect to the sun king. In the sky, the Sun reaches its maximum north declination (+ 23º 27 ‘) and for several days its maximum height at noon does not change. At the same time that this happens, winter begins in the southern hemisphere.
Another characteristic of summer is that it is the season that lasts the longest, because the Earth moves more slowly along its orbit, but the distance that the Earth travels from the autumnal equinox to the spring equinox is less than the that runs from the spring equinox to the autumn equinox. Something that can be demonstrated thanks to Kepler’s laws of the motion of the planets.
Image: National Astronomical Observatory / astronomia.ign.es
The reason why summer is the shortest season of the year is found, as we noted, in Kepler’s Second Law. The orbit that the planets describe around their star is elliptical, which means that not all points are at the same distance from their center, which is the star around which they orbit. The second law comes to say that planets move faster when they are closest to their star , and they move slower at the farthest point.
Although it may seem counterintuitive to us, in summer there is the moment of maximum distance between the Earth and the Sun (also known as aphelion). Therefore, the Earth moves more slowly, resulting in a slightly longer season (93 days compared to 89 in winter and autumn). In summer, the distance from the Earth to the Sun is just over 152 million kilometers , 5 million further than at the time of shortest distance (known as perihelion), which this year took place on January 3, 2019.
Celestial bodies that will be more visible
Until mid-July, both Venus and Saturn will be highly visible at sunrise. Instead, at dusk Jupiter, Saturn and Mars will be visible.
Astronomical phenomena
On July 2 there will be a total solar eclipse that will be visible in the South Pacific and South America. The second and last eclipse of the summer will be of the Moon, and will take place on the night of July 16 to 17, being visible in America, Europe (also from Spain) and Africa.
This summer we will also witness two major meteor showers. First, those known as aquarid deltas, which have a period of maximum activity around July 30; and, second, the Perseids, whose peak of activity will take place on August 12. Three days later, on August 15, we will see Luna lluna and, as there is more light in the sky, this will make it difficult to see the Perseids that night. Take this into account if you plan to go out to the country to enjoy them!
