February will be an interesting month with the sky’s brightest stars and constellations well placed for viewing in the southeastern sky. Very bright Jupiter will be unmistakable to their right (or westward). However, the other planets will be more of a challenge. Bright Saturn will start February low in the southwestern sky and drop lower each day. It will be lost in the twilight glow by mid month. In the predawn sky, Mercury probably will be too close to the Sun to be seen, and brilliant Venus will be dropping lower each day and may be hard to spot by the end of February. Meanwhile, Mars will be crawling slowly up out of the Sun’s glow and should be easier to find by the end of the month. Mars and Venus will pass each other on the morning of the 22nd.

February is best known as the shortest month of the year and the month when a leap day is added every four years. It is called a “leap” day because succeeding dates leap over a day of the week. For example, in 2023, March 1 was on a Wednesday, but this year has a leap day, so March 1 leaps over Thursday and falls on a Friday. A leap day is needed because the Earth takes 365.25 days to obit the Sun, so without a leap day the calendar would drift away from the seasons. Such was the case in ancient Rome when Julius Ceasar developed a calendar that is very close to what we have today.

Since the year at that time started in March, he gave March 31 days and alternated the subsequent months with 30 and 31 days This used 336 days. That left 29 days to be given to the last month, February, with an extra day every four years. He also changed the start of the year to January. Everything was fine until the Romans decided to name a month August after the birth month of Caesar Augustus. That month followed July, which was named for the birth month of Julius Caesar. Since July had 31 days, it would have been an insult if August had 30 days. August was given 31 days and the subsequent alteration was changed, but January was kept at 31 days because of its cultural significance. This gave the calendar 337 days through January, so February was given one less day, or 28, with an extra day every four years

Unfortunately, the year is about 11 minutes shorter than 365.25 days, so by 1582 the calendar was again getting out of whack. Pope Gregory XIII corrected this by dropping leap days in century years that are not divisible by 400. Also, 10 days were dropped, and the day after Thursday, October 4, 1582 was Friday, October 15. Protestant countries resisted using the Pope’s calendar, so it was not until 1752 that all countries started to use it. By then, those countries needed to skip 11 days to correct the calendar.

Observing Highlights

-Feb. 4: The Moon will be upper right of Antares, the reddish heart of Scorpius (the Scorpion), before sunrise. By the 5th, the Moon will have moved in its orbit and be to the lower left of Antares.

-Feb. 6: The crescent Moon will be to the upper right of brilliant Venus and close to its lower right on the 7th. They will be quite low in the sky, so you will need a clear eastern horizon to see them. You may also be able to pick out Mars with binoculars to the lower left of Venus.

-Feb. 10: The very thin crescent Moon will be below Saturn very low in the west-southwestern sky. Binoculars will help.

-Feb. 14: The Moon will be close to the lower right of the very bright Jupiter.

-Feb. 16: The Moon will be above Aldebaran and close to the lower left of the Pleiades open star cluster in Taurus (the Bull). However, the Moon will probably be too bright to see the Pleiades.

-Feb. 20: The bright Moon will be close to the lower right of Pollux with Castor above in Gemini (the Twins).

-Feb. 22: Brilliant Venus will pass much fainter Mars very low in the predawn sky. They will be close from the 20th through the 24th. Start looking about 45 minutes before sunrise. Binoculars may be helpful to see Mars.

-Feb. 27: The Moon will be close above Spica in Virgo (the Maiden) after they rise at about 10:00.