the moon and the stars, which thou hast ordained;
What is man, that thou art mindful of him?
Psalm 8:3,4
(From Astronomy and Sky & Telescope Magazines)
Sunday, December 15
The last Full Moon of 2024 occurs at 4:02 A.M. EST. December’s Full Moon is also called the Cold Moon, as it occurs when colder temperatures are falling across North America.
Monday, December 16
The Moon, now waning gibbous, rises around the end of twilight and is reasonably high by an hour later. It forms a triangle with Pollux and Castor about 5° to its right. Watch the triangle change shape through the night as the Moon moves eastward along its orbit.
Tuesday, December 17
Late this evening, the bright white waning Moon shines in the east just above fire-colored Mars. They rise about an hour after dark and are nicely up an hour later. These are currently the closest major objects in the solar system, 1.3 light-seconds and 5.9 light-minutes from your eyes.
Slowly setting toward the horizon as the evening progresses, Saturn now hangs some 40° high in the south an hour after sunset. Glowing at magnitude 1 through the end of the year, the ringed planet is the brightest point of light in Aquarius and the surrounding constellations, hanging below the Circlet of Pisces. Closer to the horizon, directly below Saturn in the early evening, is magnitude 1.2 Fomalhaut, Piscis Austrinus’ alpha star.
Wednesday, December 18
The Moon passes 0.9° north of Mars at 4 A.M. EST. You can easily catch the pair before
sunrise this morning — an hour before local sunrise, they’re 40° high in the west in central Cancer, near the Beehive open cluster (M44).
Thursday, December 19
With no Moon in the evening sky, the stars of the Little Dipper will be discernible to the naked eye from a dark site tonight. Early in the evening, the dipper is swinging from west to east, hanging directly from its handle mid-evening.
Pinned in the north, this famous asterism is part of the larger constellation Ursa Minor the Little Bear. Its handle is anchored by the North Star, the only star in the northern sky that does not appear to move as Earth rotates on its axis. Also cataloged as Alpha (α) Ursae Minoris or Polaris, this 2nd-magnitude star is far from the brightest, but gets its notoriety from its current location above the North Celestial Pole.
Last year, this year, and next, we see the orbital plane of Jupiter's moons tilted a bit to our line of sight. So from our viewpoint, the moons can deviate from their usual nearly straight line east and west of the planet.
For instance, tonight around midnight EST, when Jupiter is high for all of North America, Ganymede, Callisto, and Europa form a surprising isoceles triangle east of the planet, while Io looks on from Jupiter's western side.
Friday, December 20
Now the late-night waning Moon pairs up with Regulus. Look east after about 10 p.m.
Mercury reaches 50 percent lit today, an event you can observe in the early-morning sky in the hour before sunrise. The planet has brightened to magnitude 0 and stands near the border of Scorpius and Ophiuchus, already some 7° high an hour before sunrise.
Saturday, December 21
This is the shortest day of the year in the Northern Hemisphere; the longest day in the Southern Hemisphere. The solstice occurs at 4:20 a.m. EST, when the Sun reaches its farthest southern declination and begins its six-month return northward.
The last Full Moon of 2024 occurs at 4:02 A.M. EST. December’s Full Moon is also called the Cold Moon, as it occurs when colder temperatures are falling across North America.
Monday, December 16
The Moon, now waning gibbous, rises around the end of twilight and is reasonably high by an hour later. It forms a triangle with Pollux and Castor about 5° to its right. Watch the triangle change shape through the night as the Moon moves eastward along its orbit.
Tuesday, December 17
Late this evening, the bright white waning Moon shines in the east just above fire-colored Mars. They rise about an hour after dark and are nicely up an hour later. These are currently the closest major objects in the solar system, 1.3 light-seconds and 5.9 light-minutes from your eyes.
Slowly setting toward the horizon as the evening progresses, Saturn now hangs some 40° high in the south an hour after sunset. Glowing at magnitude 1 through the end of the year, the ringed planet is the brightest point of light in Aquarius and the surrounding constellations, hanging below the Circlet of Pisces. Closer to the horizon, directly below Saturn in the early evening, is magnitude 1.2 Fomalhaut, Piscis Austrinus’ alpha star.
Wednesday, December 18
The Moon passes 0.9° north of Mars at 4 A.M. EST. You can easily catch the pair before
Thursday, December 19
With no Moon in the evening sky, the stars of the Little Dipper will be discernible to the naked eye from a dark site tonight. Early in the evening, the dipper is swinging from west to east, hanging directly from its handle mid-evening.
Pinned in the north, this famous asterism is part of the larger constellation Ursa Minor the Little Bear. Its handle is anchored by the North Star, the only star in the northern sky that does not appear to move as Earth rotates on its axis. Also cataloged as Alpha (α) Ursae Minoris or Polaris, this 2nd-magnitude star is far from the brightest, but gets its notoriety from its current location above the North Celestial Pole.
Last year, this year, and next, we see the orbital plane of Jupiter's moons tilted a bit to our line of sight. So from our viewpoint, the moons can deviate from their usual nearly straight line east and west of the planet.
For instance, tonight around midnight EST, when Jupiter is high for all of North America, Ganymede, Callisto, and Europa form a surprising isoceles triangle east of the planet, while Io looks on from Jupiter's western side.
Now the late-night waning Moon pairs up with Regulus. Look east after about 10 p.m.
Mercury reaches 50 percent lit today, an event you can observe in the early-morning sky in the hour before sunrise. The planet has brightened to magnitude 0 and stands near the border of Scorpius and Ophiuchus, already some 7° high an hour before sunrise.
Saturday, December 21
This is the shortest day of the year in the Northern Hemisphere; the longest day in the Southern Hemisphere. The solstice occurs at 4:20 a.m. EST, when the Sun reaches its farthest southern declination and begins its six-month return northward.
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