February 11, 2023: Daylight is longer than darkness today until Halloween. Venus moves towards Jupiter in the west-southwest, while Mars marches to the east against Taurus.
by Jeffrey L. Hunt
Chicago, Ill.: Sunrise, 6:52 am CST; Sunset, 5:19 p.m. CST. Check local sources for sunrise and sunset times for your location. Times are calculated from the US Naval Observatory. MICA Computer program.
Transit times of Jupiter’s Great Red Spot, when it is at the center of the planet in the southern hemisphere: 9:28 UT, 19:24 UT; February 12, 5:20 UT. Convert the time to your time zone. In the US, subtract five hours for EST, six hours for CST, and so on. Use a telescope to see the place. The times are from sky and telescope magazine.
Today the daylight is longer than the darkness. This statement is not about the next equinox when the light of day and night are almost equal. Let’s distinguish some terminology. When the sun is in the sky it is day. When it is not, it is night.
Night can be divided into twilight (both evening and morning) and darkness, when the sky is as dark as is natural. This occurs when the sun is 18° below the horizon. Night occurs in three phases, evening twilight, darkness, and morning twilight.
In the graph above, calculated from US Naval Observatory data, three lines show daylight, darkness, and twilight, adding morning twilight and evening twilight.
Red diamonds show today’s date, when daylight is longer than darkness. It is 10 hours, 27 minutes compared to the 10 hours, 24 minutes of darkness. The daylight curve increases a bit during the equinox on March 20.the, when the length of daylight is 12 hours, 9 minutes. Darkness is 8 hours, 45 minutes.
On the summer solstice, daylight lasts 15 hours and 13 minutes. Darkness decreases to 4 hours, 23 minutes. Interestingly, twilight is a minute or two longer than darkness since June 17.the until June 26the.
After the solstice, daylight begins to wane and darkness lengthens. By the equinox on September 23, the sun is above the horizon for 12 hours and 8 minutes and darkness increases to 8 hours and 45 minutes.
On Halloween, daylight is four minutes shorter than darkness and continues for more than 100 days at Chicago’s latitude. Daylight continues to decrease until the solstice on December 21 with 9 hours and 8 minutes of sunlight.
The dates this occurs vary with latitude. Locations further south suffer from shorter periods when darkness is longer than sunlight. Farther north, the interval is longer.
In Miami, Florida, daylight got longer on January 11the; in Tucson, January 30the. From Seattle, Washington, the interval ends in four days, but Juneau, Alaska doesn’t arrive in this state until March 21.st120 days when darkness is longer than daylight.
However, Juneau experiences a phase without darkness from April 27 to August 15.the. It has daylight and twilight that does not go into darkness.
Here is the planet’s forecast for today:
The 72% illuminated gibbous moon is about a third of its height in the southwestern sky, and 3.1° to the upper left of Spica, the brightest star in Virgo. The lunar orb continues its eastward journey, passing through the half-full phase, Last Quarter, on the 13th.the.
Mercury continues its morning dip in bright sunlight. Rising an hour before sunrise, the planet is at only 4° and in the glow of the approaching dawn.
Saturn, which sets just fifteen minutes after sunset, is closer to the sun in the sky than Mercury. The ringed wonder is conjunct in the far arc of its solar orbit in five days.
Forty-five minutes after sunset, Venus shines brightly in the west-southwest sky. It is about 15° above the horizon 45 minutes after sunset. Its brilliance competes with the lights of low-flying planes or blends in with something out of this world.
Bright Jupiter is higher in the sky and 18.5° to the upper left of Venus. The Jovian giant moves slowly through Cetus. Venus moves faster to the east and reaches Jupiter on March 1st in a spectacular conjunction. A Venus-Jupiter conjunction at twilight is an amazing event.
The best night is March 1st.stgoal of february 20the until March 11the, Venus is 10° from Jupiter. The two brightest stellar bodies are close to each other.
Ten degrees is roughly the distance from the thumb to the little finger on the fist when extended at arm’s length. Close one eye and look through your fist to feel the distance. Similarly, the final arc from the sun to sunset each day is about 15°. The nail of the little finger, when extended to the length of the arm, measures about half a degree. Cover the full moon or the sun. Try it.
At this time, Mars is in the southeast, marching east with Taurus as a starry backdrop. In another 45 minutes, the background stars are easily visible behind the Red Planet.
Mars is 8.6° to the upper left of Aldebaran and 10.1° from Elnath, the northern horn of the Bull.
The gibbous moon rises after midnight tomorrow morning.