A full moon rises over Utah.
Credits: NASA/Bill Dunford
The next full moon is the Crow, Crust, Sap, Sugar, or Worm Moon; the Paschal Moon; Purim; the Holi Festival Moon; Madin Poya; the Pothole Moon; a Micromoon, and a Partial Lunar Eclipse.
The next full moon will be on Monday morning, March 25, 2024, appearing opposite the Sun in Earth-based longitude at 3 AM EDT. This will be on Sunday evening from Alaska Time westward to the International Date Line. Around this time the Moon will pass through the partial shadow of the Earth (called a penumbral lunar eclipse). The slight dimming of the Moon will be difficult to notice, but see if you can tell if the lower part of the Moon is dimmer than the upper part. The Moon will begin entering the Earth’s shadow at 12:53 AM, reach greatest eclipse at 3:13 AM with 96% of the Moon in partial shadow, and exit the shadow at 5:32 AM. Since this full Moon is a little over a day after apogee (when the Moon is at its farthest from the Earth in its orbit) this is a micromoon, the opposite of a supermoon. The Moon will appear full for about 3 days around this time, from Saturday evening through Tuesday morning.
The Maine Farmers’ Almanac began publishing “Indian” names for full Moons in the 1930s and these names are now widely known and used. According to this almanac, as the full Moon in March the tribes of the northeastern United States called this the Crow, Crust, Sap, Sugar, or Worm Moon. The more northern tribes of the northeastern States knew this as the Crow Moon, with the cawing of crows signaling the end of winter. Other northern names were the Crust Moon, because the snow cover became crusted from thawing by day and freezing by night, or the Sap (or Sugar) Moon as this was the time for tapping maple trees. The more southern tribes called this the Worm Moon after the earthworm casts that appeared as the ground thawed. It makes sense that only the southern tribes called this the Worm Moon. When glaciers covered the northern part of North America they wiped out the native earthworms. After these glaciers melted about 12,000 years ago the more northern forests grew back without earthworms. Most of the earthworms in these areas are invasive species introduced from Europe and Asia.
In the western Christian ecclesiastical calendar this is the Paschal Moon, from which the date of Easter is calculated. Paschal is the Latinized version of Pesach, Hebrew for Passover. Initially, the Christian holiday of Easter, also called Pascha, was celebrated on the first Sunday after the first full Moon of spring. However, there are differences between the times of these astronomical events and the calendars now used by the Eastern and Western churches. Western Christianity will be celebrating Easter on Sunday, March 31, 2024, the Sunday after this first full Moon of spring. The date of Eastern Orthodox Easter is based on the Julian calendar and will be on Sunday, May 5.
Many lunar and lunisolar calendars start the months on the new Moon with the full Moon in the middle of the month. Lunisolar calendars add or repeat a month as needed to keep the lunar months aligned with the solar seasons. This full Moon is in the middle of the second month of Adar in the Hebrew calendar and corresponds with Purim, celebrated from sunset on March 23 to sunset on March 24, 2024, the 14th of the Adar II (a day later in Jerusalem and ancient walled cities). Purim marks the Jewish people’s deliverance from a royal death decree around the fourth century BCE as told in the Book of Esther. Purim is celebrated by exchanging gifts of food and drink, feasting, and donating to charity.
In the Islamic calendar this full Moon is near the middle of the holy month of Ramadan. Ramadan is honored as the month in which the Quran was revealed. Observing this annual month of charitable acts, prayer, and fasting from dawn to sunset is one of the Five Pillars of Islam.
As the full Moon in the Hindu month Phalguna, this Moon corresponds with the Holi festival, celebrating the victory of good over evil and the start of spring. This two-day long festival is also known as the Festival of Love, Festival of Colors, or the Festival of Spring. Holi begins with a bonfire the evening before the day of the full Moon, continues on the day of the full Moon with a free-for-all game involving the spraying of colored powders and/or colored water on whomever wanders by, and ends with evening visits with friends and family.
Every full Moon is a holiday in Sri Lanka. This full Moon is Medin or Madin Poya, marking the Buddha’s first visit to his father after his enlightenment.
Continuing the tradition of naming Moons after prominent phenomena tied to the time of year, a few years ago my friend Tom Van Wagner suggested naming this the Pothole Moon. It may be a case of confirmation bias, but whether in my car or on my bicycle I notice more potholes this time of year.
As usual, the wearing of suitably celebratory celestial attire is encouraged in honor of the full Moon.
As for other celestial events between now and the full Moon after next (with specific times and angles based on the location of NASA Headquarters in Washington, DC):
There will be a total eclipse of the Sun on Monday, April 8, 2024. This total eclipse will be visible in a swath ranging from 142 (88 miles) wide near the start and end to 203 km (126 miles) wide near the middle of the swath. The path of the total eclipse will begin in the Pacific south of the equator, start passing over North America on the coast of Mexico near Mazatlán, cross the USA from Texas to Maine, exit North America from Canada on the coast of Newfoundland, and end in the North Atlantic. Outside of this narrow swath, most of North and Central America will see a partial solar eclipse. See https://science.nasa.gov/solar-system/skywatching/eclipses/solar-eclipses/2024-solar-eclipse/total-solar-eclipse-2024-the-moons-moment-in-the-sun/ for more information.
Assuming you can find a place with clear skies near the centerline of this swath, this eclipse, in particular, should be quite a show. Compared to the eclipse in 2017, the Moon will be nearer its closest to the Earth, making its shadow larger, the sky darker, and the eclipse longer. In addition, the Sun will be nearer its maximum in its 11-year cycle, so the corona, which can only be seen during a total eclipse, should be more spectacular. If the sky is clear during the eclipse, you will be able to see the planets and some stars that are not normally visible this time of year. Bright Jupiter will be to the upper left of the eclipse, with Venus, Saturn, and Mars to the lower right. In the unlikely event that the comet 12P/Pons-Brooks has an outburst that makes it significantly brighter (described below), you may be able to see it to the right of Jupiter (if it isn’t obvious, I recommend enjoying the eclipse rather than spending time searching for a comet you might not be able to see).
Plenty of information about this total eclipse is available elsewhere, so I will refrain from adding much more, but please read and pay attention to eye safety. The only time it is safe to look directly at the Sun is when it is completely blocked by the Moon, so that you can only see the much fainter corona. Staring directly at even a small sliver of the Sun can do permanent eye damage.
This eclipse will be passing through or near many populated areas, making it possible to trade off waiting for more accurate weather forecasts for clear skies against the difficulties of making last minute bookings or dealing with traffic jams if you wait until the day of the eclipse to drive to the zone of totality.
Total eclipses of the Sun are rare and spectacular events. I recognize that not everyone will be able to drop everything and go see this one, but seeing at least one good, total eclipse in a clear sky should be on your bucket list. A partial eclipse is just not the same. The only other reason I can think of for not going where you can see this total eclipse (other than you absolutely can’t at this time) is that if you see this eclipse, you are likely to want to see more, and will begin making plans to go to North Africa in 2026, Australia in 2028, etc. The next three eclipses visible from parts of North America will be in 2044, 2045, and 2052.
During this lunar cycle, comet 12P/Pons-Brooks will be visible with binoculars or a telescope, and may become bright enough to be a naked eye comet. In my quick searches of the web I found visual guides that provide specific information on when and where to look from your location on any given night. However, I did not see a concise guide to when might be the best time to look for this comet, so here is my meager attempt.
Several things make a difference in how easy it is to see a comet.
The greatest uncertainty is how much dust and gas it will be giving off, as it is the sunlight illuminating these plumes that make the comet bright. This comet has already had outbursts that have made it temporarily 10 to 100 times brighter. It may be less likely such outbursts will occur as the comet moves closer to the Sun, but this is uncertain. As the astronomer David H. Levy said, “Comets are like cats; they have tails, and they do precisely what they want.”
My recommendation is to pay attention to the news and check regularly to see if the comet has had an outburst, as this may push its brightness into the visible range. In addition, I plan to look for the comet with binoculars, both on April 8 and 9 before moonlight begins to interfere and in the weeks before closest approach to the Sun on April 21. The next couple of paragraphs give my reasoning (which you are welcome to skip if you like).
We can’t predict outbursts, but we can predict other influences on the brightness of the comet.
If the gas and dust from the comet isn’t changing, an easy calculation is to assume the comet will scatter light uniformly in all directions, so that all you need to consider is the distance between the Sun and the comet and the distance between the comet and the Earth. This suggests that the comet will be at its brightest around April 20 and 21, 2024, when it will be passing its closest to the Sun and receiving (and reflecting towards Earth) the maximum amount of sunlight.
How easy the comet will be to see will also depend on how much glow there is from twilight (which depends on how far the Sun is below the horizon), whether (and how much) moonlight there is (increased moonlight will brighten the background sky), and how high the comet is above the horizon.
In the evenings, nautical twilight ends when the Sun reaches 12 degrees below the horizon (the estimate of when the horizon will be too dark for sailors at sea to use for navigation). In mid-to-late April (for the DC area), nautical twilight ends about 1 hour after sunset (the start and end of twilight I use throughout these Moon Missives is based on nautical twilight). Astronomical twilight is when the Sun is between 12 and 18 degrees below the horizon, when the sky looks dark but there can be enough residual glow that the faintest stars and diffuse objects (like nebulae, galaxies, faint meteors, and comets on the edge of visibility) may be masked. When the Sun is more than 18 degrees below the horizon the sky is about as dark as it is going to get.
When the Moon is in the sky it will add its light to the background brightness of the sky. The amount of light added will increase as the Moon waxes from a faint, thin crescent to a bright, nearly full Moon.
The evening of April 8, 2024, as nautical twilight ends (at 8:39 PM EDT), the crescent Moon will have already set and the comet will be 11.4 degrees above the west-northwestern horizon. The combined effect of the range from the Sun and the Earth gives a geometric estimate of 91% of the maximum brightness at its closest to the Sun in late April. By the time astronomical twilight ends (at 9:12 PM) the comet will still be 5 degrees above the horizon.
The evening of April 9, it might be interesting to see the comet and the thin, waxing crescent Moon low on the horizon as twilight ends, as the Moon will not be very bright and should not interfere much with seeing the comet. Nautical twilight will end (at 8:40 PM) with the Moon 4.2 degrees above the horizon and the comet above the Moon at 10.8 degrees above the horizon. The Moon will set (at 9:08 PM) just 5 minutes before astronomical twilight ends (at 9:13 PM), when the comet will be 4.6 degrees above the horizon. The distance-based estimate of brightness will have increased to 93% of the peak in late April.
Between April 10 and April 21, the geometric estimate of the brightness of the comet will gradually increase, but so will interference from the brightness of the waxing Moon, and the comet will shift closer to the horizon each evening. On the evening of April 21 the geometric brightness of the comet will be at its greatest, but the Moon will be 96% illuminated and the comet will be only 2.7 degrees above the horizon as nautical twilight ends. April 24 will be the last evening that the comet will be above the horizon before nautical twilight ends (at 8:57 PM).
Note that as our opportunity to view this comet from northern latitudes gets worse in late April, the opportunity for viewers in the Southern Hemisphere will get better.
As spring continues the daily periods of sunlight continue to lengthen, having changed at their fastest around the equinox on March 19, 2024. On Monday, March 25 (the day of the full Moon), morning twilight will begin at 6:05 AM, sunrise will be at 7:03 AM, solar noon will be at 1:14 PM when the Sun will reach its maximum altitude of 53.3 degrees, sunset will be at 7:25 PM, and evening twilight will end at 8:24 PM. By Tuesday, April 23 (the day of the full Moon after next), morning twilight will begin at 5:18 AM, sunrise will be at 6:20 AM, solar noon will be at 1:06 PM when the Sun will reach its maximum altitude of 64.0 degrees, sunset will be at 7:53 PM, and evening twilight will end at 8:56 PM.
Two meteor showers, the Lyrids (006 LYR) and the π-Puppids (137 PPU), will peak near the end of this lunar cycle but the nearly full Moon will interfere with seeing these meteors.
On the evening of Sunday, March 24 (the evening before the full Moon), as twilight ends (at 8:22 PM EDT), the rising Moon will be 14 degrees above the east-southeastern horizon. The bright planet Jupiter will be 27 degrees above the western horizon and the planet Mercury will be to the lower right of Jupiter at 7 degrees above the horizon. The bright object appearing closest to overhead will be Pollux at 78 degrees above the south-southeastern horizon. Pollux is the 17th brightest star in our night sky and the brighter of the twin stars in the constellation Gemini the twins. Pollux is an orange tinted star about 34 light-years from Earth. It is not quite twice the mass of our Sun but about 9 times the diameter and 33 times the brightness.
As this lunar cycle progresses, the background of stars will appear to shift westward each evening (as the Earth moves around the Sun). Mercury will be dimming as it shifts toward the west-northwestern horizon, with April 3 the last evening it will be above the horizon as twilight ends and April 11 when it will pass between the Earth and the Sun, shifting from the evening to the morning sky. We are approaching the end of the opportunity to view Jupiter for this apparition, as it will shift lower towards the west-northwestern horizon each evening. The waxing Moon will pass by Jupiter on April 10, Pollux on April 14 and 15, Regulus on April 17 and 18, and Spica on April 22. By the evening of Tuesday, April 23 (the evening of the day of the full Moon after next), as twilight ends (at 8:56 PM EDT), the rising Moon will be 10 degrees above the east-southeastern horizon. The bright planet Jupiter will be 4 degrees above the west-northwestern horizon. The bright object appearing closest to overhead will be Regulus at 63 degrees above the southern horizon. Regulus is the 21st brightest star in our night sky and the brightest star in the constellation Leo the lion. The Arabic name for Regulus translates as “the heart of the lion.” Although we see Regulus as a single star, it is actually four stars (two pairs of stars orbiting each other). Regulus is about 79 light-years from us.
On the morning of Monday, March 25 (the morning after the full Moon), as twilight begins (at 6:05 AM EDT), the setting Moon will be 12 degrees above the west-southwestern horizon. The planet Mars will be 3 degrees above the east-southeastern horizon. The bright object appearing closest to overhead will be the star Vega at 73 degrees above the eastern horizon. Vega is the brightest star in the constellation Lyra the lyre and is one of the three bright stars in the “Summer Triangle” along with Deneb and Altair. Vega is the 5th brightest star in our night sky, about 25 light-years from Earth, twice the mass of our Sun, and shines 40 times brighter than our Sun.
As this lunar cycle progresses, the background of stars will appear to shift westward each evening, while Mars will hover low on the east-southeastern horizon, drifting slightly to the left. The waning Moon will pass by Spica on March 26 and 27, and Antares on March 30. April 1 will be the first morning the planet Saturn will be above the eastern horizon as morning twilight begins, shifting towards Mars each morning. On April 6 the thin, waning crescent Moon will form a triangle with Saturn and Mars, but will be low on the east-southeastern horizon and difficult to see, with the Moon rising just 3 minutes before morning twilight begins. On April 10 Mars and Saturn will appear closest to each other, after which they will appear to separate. By the morning of Tuesday, April 23 (the morning of the day of the full Moon after next), as twilight begins (at 5:18 AM EDT), the setting full Moon will be 7 degrees above the west-southwestern horizon with the bright star Spica 2.5 degrees to the lower left of the Moon. The planet Mars will be 5 degrees above the eastern horizon and the planet Saturn will be 7 degrees above the east-southeastern horizon. The bright object appearing closest to overhead will still be the star Vega at 86 degrees above the eastern horizon.
Here for your reference is a day-by-day listing of celestial events between now and the full Moon after next. The times and angles are based on the location of NASA Headquarters in Washington, DC, and some of these details may differ for where you are (I use parentheses to indicate times specific to the DC area).
Monday evening into Tuesday morning, March 18 to 19, 2024, the bright star Pollux (the brighter of the twin stars in the constellation Gemini the twins) will appear near the waxing gibbous Moon. Pollux will be 3.5 degrees to the left as twilight ends (at 8:16 PM EDT) and will shift clockwise around the Moon until the Moon sets on the northwestern horizon (at 4:42 AM) when Pollux will be 2 degrees to the upper right.
Tuesday evening, March 19, 2024, at 11:06 PM EDT, will be the vernal equinox, the astronomical end of winter and start of spring. For a location on the equator in the ocean north of Western New Guinea the Sun will pass directly overhead as it shifts from the Southern to the Northern Hemisphere.
Thursday morning, March 21, 2024, if you have a very clear view of the horizon about halfway between east and east-southeast, you might be able to see the planet Saturn less than a degree to the lower left of the bright planet Venus. Because of the glow of dawn this will be hard to see. Venus will shine brighter than any star, but Saturn will rise last (at 6:32 AM), 21 minutes after twilight begins (at 6:11 AM EDT), and will be only a little brighter than the star Pollux, the 17th brightest star in our night sky. You may need binoculars to see the pair, but make sure you stop looking well before sunrise.
The next morning, Friday, March 22, 2024, the planet Venus will have shifted to less than a degree to the left of the planet Saturn, with the pair rising together (at 6:29 AM EDT) 19 minutes after twilight begins (at 6:10 AM).
Thursday evening into Friday morning, March 21 to 22, 2024, the bright star Regulus will appear near the waxing gibbous Moon. As twilight ends (at 8:19 PM EDT) Regulus will be 5 degrees to the lower right of the Moon. Regulus will gradually shift closer to the Moon, initially swinging towards the left (appearing 4 degrees below and a little to the left) as the Moon reaches its highest (at 11:13 PM). At about 2:30 AM (when Regulus will be 3 degrees to the lower left) Regulus will switch and start swinging towards the right. As Regulus sets (at 5:58 AM) it will be 2.5 degrees below the Moon, with morning twilight beginning 12 minutes later (at 6:10 AM) and the Moon setting 3 minutes after that (at 6:13 AM).
Saturday night, March 23, 2024, at 11:46 AM EDT, the Moon will be at apogee, its farthest from the Earth for this orbit.
Sunday evening, March 24, 2024, at 5:59 PM EDT, will be when the planet Mercury reaches its greatest angular separation from the Sun as seen from Earth for this apparition (called greatest elongation). This will be the evening when the planet Mercury will appear highest above the western horizon (6.5 degrees) as twilight ends (at 8:22 PM).
As mentioned above, the next full Moon will be on Monday morning, March 25, 2024. The Moon will pass through the partial shadow of the Earth (called a penumbral lunar eclipse), beginning to enter the shadow at 12:53 AM EDT, reaching greatest eclipse at 3:13 AM when 96% of the Moon will be in partial shadow, and exiting the shadow at 5:32 AM. The slight dimming of the Moon will be difficult to notice. Since this is a little over a day after apogee (when the Moon is at its farthest from the Earth in its orbit) this will be a micromoon, the opposite of a supermoon. The Moon will appear full for about 3 days around this time, from Saturday evening through Tuesday morning.
Tuesday morning, March 26, 2024, the bright star Spica will appear near the full Moon. As the Moon reaches its highest in the sky for the night (at 1:52 AM EDT), Spica will be 8 degrees to the lower left of the Moon. By the time twilight begins (at 6:03 AM), Spica will be 6 degrees to the left of the Moon.
Tuesday evening into Wednesday morning, March 26 to 27, 2024, the Moon will have shifted to the other side of Spica. As the Moon rises on the east-southeastern horizon (at 8:59 PM EDT), Spica will be 3 degrees to the upper right of the Moon. By the time the Moon reaches its highest for the night (at 2:32 AM), Spica will be 5 degrees to the upper right. Spica will be 6 degrees to the lower right as twilight begins (at 6:02 AM).
Saturday morning, March 30, 2024, the bright star Antares will appear near the waning gibbous Moon. As Antares rises on the southeastern horizon (at 12:37 AM EDT) it will be 5 degrees to the lower left of the Moon. The Moon will reach its highest for the night (at 4:52 AM) with Antares 3 degrees to the left. As twilight begins (at 5:57 AM) Antares will be a little less than 3 degrees to the upper left of the Moon.
Monday morning, April 1, 2024, will be the first morning that the planet Saturn will be above the eastern horizon as twilight begins (at 5:55 AM EDT).
Monday night, April 1, 2024, the waning Moon will appear half-full as it reaches its last quarter at 11:15 PM EDT (when the Moon will be below the horizon).
Wednesday evening, April 3, 2024, will be the last evening that the planet Mercury will be above the horizon as twilight ends.
Saturday morning, April 6, 2024, if you have a very clear view of the east-southeastern horizon, you might be able to see the thin, waning crescent Moon near the planets Saturn and Mars. The Moon will rise last (at 5:42 AM EDT) just 3 minutes before twilight begins, with
Saturn 2 degrees to the upper left of the Moon and Mars 4 degrees to the upper right of the Moon.
You will need binoculars to see them in the glow of dawn, but on Sunday morning, April 7, 2024, the bright planet Venus will appear 3.5 degrees to the left of the very thin, waning crescent Moon low on the eastern horizon. Venus will rise last (at 6:14 AM EDT) 31 minutes after twilight begins and 29 minutes before sunrise. If you are using binoculars to scan for this pairing, be sure to stop looking well before any chance of sunrise (as using high powered lenses to focus intense sunlight directly into your eyes is a really bad idea).
Sunday afternoon, April 7, 2024, at 1:52 PM EDT, the Moon will be at perigee, its closest to the Earth for this orbit.
There will be an eclipse of the Sun on Monday, April 8, 2024. For information on the total solar eclipse (not visible from the Washington, DC area) see the summary section above. The Washington, DC area will only see a partial eclipse, starting at about 2:04 PM EDT, reaching its peak at about 3:21 PM when 88.9% of the Sun will be blocked by the Moon, and ending at 4:33 PM. Please pay attention to eye safety and do not look at the Sun directly without eclipse glasses. When the Moon is blocking most of the Sun, what remains will appear like a crescent. One of the interesting effects is that the sunlight through trees, etc., that we normally see as mottled sunlight (round blotches of light) is actually made up of many small images of the round Sun. When the Sun appears as a crescent these mottled patches will appear as many small crescents.
The eclipse will also be the new Moon, when the Moon passes between the Earth and the Sun and is not usually visible from the Earth (except when its silhouette causes an eclipse). The day of or the day after the new Moon marks the start of the new month for most lunisolar calendars. Sundown on Monday, April 8, 2024, marks the start of Nisan in the Hebrew calendar. Pesach or Passover begins on the 15th day of Nisan. The third month of the Chinese calendar starts on Tuesday, April 9, 2023.
Monday evening, April 8, 2024, as nautical or evening twilight ends (at 8:39 PM EDT), comet 12P/Pons-Brooks will be 11.4 degrees above the west-northwestern horizon. The crescent Moon will have already set, making this the last evening to see this comet without moonlight. By the time astronomical twilight ends (at 9:12 PM) the comet will still be 5 degrees above the horizon.
In the Islamic calendar the months traditionally start with the first sighting of the waxing crescent Moon. Many Muslim communities now follow the Umm al-Qura Calendar of Saudi Arabia, which uses astronomical calculations to start months in a more predictable way. This calendar predicts the holy month of Ramadan will end and ShawwÄl will begin with sunset on Tuesday, April 9, 2024. Because of the religious significance of the end of Ramadan, ShawwÄl is one of 4 months in the Islamic year where the start of the month is updated in the Umm al-Qura Calendar based upon the actual sighting of the crescent Moon. Starting with the sighting of the crescent Moon, the end of the Ramadan fast will be celebrated with Eid al-Fitr (the Feast of Breaking the Fast), a celebration lasting from 1 to 3 days.
Tuesday evening, April 9, 2024, it should be interesting to see the comet 12P/Pons-Brooks and the thin, waxing crescent Moon low on the horizon as twilight ends, as the Moon will not be very bright and should not interfere much with seeing the comet. Nautical or evening twilight will end (at 8:40 PM EDT) with the Moon 4.2 degrees above the horizon and the comet above the Moon at 10.8 degrees above the horizon. The Moon will set (at 9:08 PM) just 5 minutes before astronomical twilight ends (at 9:13 PM), when the comet will be 4.6 degrees above the horizon.
In the mornings throughout this lunar cycle the planets Saturn and Mars will appear near each other low on the east-southeastern horizon. Both will appear to shift higher each morning, with Saturn shifting more than Mars. Wednesday morning, April 10, 2024, will be when the pair will be at their closest. As twilight begins (at 5:38 AM EDT) the slightly brighter Saturn will appear 3 degrees above the horizon with Mars 0.5 degrees above Saturn.
Wednesday evening, April 10, 2024, the bright planet Jupiter will appear 4 degrees to the lower left of the waxing crescent Moon. The Moon will be 17 degrees above the west-northwestern horizon as twilight ends (at 8:41 PM EDT) and Jupiter will set first 77 minutes later (at 9:58 PM).
Thursday evening, April 11, 2024, the Pleiades star cluster will appear 6 degrees to the lower right of the waxing crescent Moon. The Moon will be 30 degrees above the western horizon as twilight ends (at 8:42 PM EDT) and the Pleiades will set first a little over 2 hours later (at about 11 PM).
Thursday evening, April 11, 2024, the planet Mercury will be passing between the Earth and the Sun, called inferior conjunction. Planets that orbit inside of the orbit of Earth can have two types of conjunctions with the Sun, inferior (when passing between the Earth and the Sun) and superior (when passing on the far side of the Sun). Mercury will be shifting from the evening sky to the morning sky and will begin emerging from the glow of the dawn on the eastern horizon later in April (depending upon viewing conditions).
Sunday evening into early Monday morning, April 14 to 15, 2024, the bright star Pollux (the brighter of the twins in the constellation Gemini the twins) will appear to the upper left of the waxing crescent Moon. As twilight ends (at 8:45 PM EDT) Pollux will be 8 degrees from the Moon. By the time the Moon sets on the west-northwestern horizon (at 2:39 AM), Pollux will be 5 degrees from the Moon.
Monday afternoon, April 15, 2024, the Moon will appear half-full as it reaches its first quarter at 3:13 PM EDT (when it will be daylight with the Moon visible in the eastern sky).
Monday evening into early Tuesday morning, April 15 to 16, 2024, the half-Moon will have shifted such that the bright star Pollux will appear to the lower right of the Moon. As twilight ends (at 8:45 PM EDT) Pollux will be 6 degrees from the Moon and the pair will appear to separate as the night progresses, reaching 8 degrees apart around 1:30 AM.
Wednesday evening into Thursday morning, April 17 to 18, 2024, the bright star Regulus will appear to the lower left of the waxing gibbous Moon. As twilight ends (at 8:49 PM EDT) Regulus will be 7.5 degrees from the Moon. When Regulus sets on the west-northwestern horizon (at 4:12 AM) it will be 4.5 degrees from the Moon.
Thursday evening into Friday morning, April 18 to 19, 2024, the waxing gibbous Moon will have shifted to the other side of the bright star Regulus. As twilight ends (at 8:50 PM EDT) Regulus will be 6 degrees to the upper right of the Moon. About 1 hour later (at 9:53 PM) the Moon will reach its highest for the night with Regulus 6 degrees to the right. Regulus will appear to rotate clockwise around and to separate from the Moon as the night progresses, reaching about 8 degrees to the lower right around 3 AM.
Friday night, April 19, 2024, at 10:09 PM EDT, the Moon will be at apogee, its farthest from the Earth for this orbit.
Friday morning, April 19, 2024, will be the first morning that the planet Mercury will rise more than 30 minutes before sunrise, a very rough estimate of the earliest it might start being visible in the glow of dawn on the eastern horizon. Mercury will be quite faint, but will brighten each morning as it presents a larger illuminated crescent towards the Earth. However, this will not be a favorable apparition for Mercury viewing, as even at its highest it will not rise before twilight begins.
Sunday, April 21, 2024 will be when the comet 12P/Pons-Brooks will be at its closest to the Sun, and the week or two before this might be a good time to look for this comet with binoculars. If the trail of gas and dust the comet is giving off doesn’t change significantly (a very big and uncertain “if”) then the brightness of the comet should gradually increase to a maximum on April 21. However, interference from the light of the waxing Moon will also increase beginning April 9, and the comet will shift closer to the horizon each evening. As twilight ends on April 21 (at 8:53 PM EDT) the Moon will be 96% illuminated and the comet will be only 2.7 degrees above the horizon. April 24 will be the last evening that the comet will be above the horizon before evening twilight ends (at 8:57 PM).
Monday evening into Tuesday morning, April 22 to 23, 2024, the bright star Spica will appear to the lower right of the full Moon. Spica will be a little more than 1 degree from the Moon as twilight ends. They will be at their closest a little before midnight. Spica will be 1 degree from the Moon as the Moon reaches its highest for the night (at 12:31 AM) and will be 2.5 degrees from the Moon as twilight begins (at 5:18 AM).
The full Moon after next will be Tuesday evening, April 23, 2024, at 7:49 PM EDT. This will be on Wednesday from the UK, Ireland, and Portugal eastward across Europe, Africa, Asia, and Australia to the International Date Line in the mid-Pacific. The Moon will appear full for about 3 days centered on this time, from Monday morning to Thursday morning.
