Autumn begins this Saturday, September 23 at 08:50 (official peninsular time). The night is quickly gaining ground on the day. It is a splendid time to enjoy the night sky as it transforms little by little. Here we indicate the ten astronomical keys for the harvest season.
1. Home. Autumn in the northern hemisphere (and spring in the south) will begin on Saturday, September 23 at 08:50 peninsular and Balearic Islands time (07:50 in the Canary Islands).
2. Night and day. The equinox is the time of year when the length of the night is equal to that of the day throughout the Earth, hence the term equinox (from the Latin aequus nocte 'equal night'). After the equinox, at the beginning of autumn, is when the night gains ground more quickly than the day: the nights become three minutes longer with each passing day.
3. Watches. Daylight saving time will end on Sunday, October 29. That day, at three in the morning (two in the Canary Islands) we will have to turn the clocks back until two (one in the Canary Islands). The change will make it dawn earlier (at the official time) and make the afternoons seem shorter.
Illumination of the Earth at the equinox
4. full moons. The first full moon of this autumn will take place on September 29 in the constellation of Pisces.. This full moon, the first after the equinox, is usually called the 'Harvest Moon', since the light of this full moon allowed the harvesting work typical of this time of year to be extended into the night.. The other two full moons of autumn will take place on October 28 and November 27.
5. Rocky. Venus will shine splendidly in the east at the end of the night and in the morning twilight, until it is engulfed in the glow of the rising sun.. The elusive Mercury will make a dawn appearance at the end of September until October 5; It can also be seen at dusk between November 25 and December 15. Mars will remain unobservable throughout the fall.
6. Giants. Jupiter and Saturn will remain visible for many hours of the autumn nights. As the season progresses, the two giants will move west to go to bed a little earlier each day. At the end of the season, Saturn will only be visible at the beginning of the night.
7. Solar eclipse. The season brings us two eclipses. The first of them, one of Sol that can be enjoyed on October 14, will be seen canceled from America. From Spain it will only be visible as partial, with very low magnitude, and only from the westernmost of the Canary Islands.
8. Lunar eclipse. The second eclipse of the fall is a partial lunar eclipse that will take place on October 28. It will be visible from Australia, Asia, Africa and Europe. Specifically, from Spain the partial phase will extend from 9:35 p.m. to 10:53 p.m. (peninsular and Balearic Islands time).
9. Shooting Stars. The Moon will allow us very favorable conditions for observing the most abundant meteor showers of the fall: the Leonids and the Geminids.. Indeed, the Leonids will reach their maximum activity around November 17, four days after the new moon, while the Geminids will have their maximum on December 13, exactly on the night of the new moon.. The lunar glow will therefore not be an obstacle to the contemplation of shooting stars.
10. 89 days. This fall will last 89 days, 20 hours and 38 minutes. It will end on Friday, December 22 with the beginning of winter.
Rafael Bachiller is director of the National Astronomical Observatory (National Geographic Institute) and academic of the Royal Academy of Doctors of Spain.