April Skies

by Dick Cookman

April 4, 2023

Highlights: Comet Journal, Martian Landers, Meteor Showers, Planet Plotting, April Moon

Focus Constellations: Ursa Major, Ursa Minor, Draco, Cepheus, Cassiopeia, Camelopardalis, Perseus, Auriga, Taurus, Gemini, Cancer, Leo, Virgo, Coma Berenices, Bootes, Hercules

• Comet Journals

Comets C/2022 E3 (ZTF) and C/2020 V2 (ZTF) have faded to 10th magnitude. The former is south of Orion and moving into southern hemisphere skies as it leaves the inner solar system. The latter moves from Triangulum to Aries in April. Perihelion occurs in May, 2023 and it is closest to Earth in September.

C/2022 A2 (PanSTARRS) is also at 10th magnitude in Andromeda. It was closest to Earth on January 17 and was at perihelion on Feb. 18.

• Mars Landers

NASA’s Perseverance rover is now on top of the river delta on the edge of Jezero Crater. After coring a rock designated as Berea, it stored the first sample of the mission’s newest science campaign on Thursday, March 30. “The Berea core highlights the beauty of rover missions,” said Perseverance’s project scientist, Ken Farley of Caltech in Pasadena. “Perseverance’s mobility has allowed us to collect igneous samples from the relatively flat crater floor during the first campaign, and then travel to the base of the crater’s delta, where we found fine-grained sedimentary rocks deposited in a dried lakebed. Now we are sampling from a geologic location where we find coarse-grained sedimentary rocks deposited in a river. With this diversity of environments to observe and collect from, we are confident that these samples will allow us to better understand what occurred here at Jezero Crater billions of years ago.”

• Meteor Showers

The Lyrid meteor shower, in the predawn dark skies after New Moon in April, can approach 90 meteors per hour, but 15 to 20 is more likely. Watch for them emanating out of northwestern skies in the hours before dawn. Pi Puppid meteors peaking on the 24th may appear rising above the eastern horizon.

• Apr. 22: Lyrids. Active Apr 16-25. Radiant 18h04m -34°. ZHR ~var<90. 49 km/sec. 2 days after New Moon. Progenitor: Comet C/1861 G1 (Thatcher).

• Planet Plottings

“Dē revolutionibus orbium coelestium” (On the Revolutions of the Heavenly Spheres) by the Polish cleric Copernicus was published when he was on his deathbed in 1543. It offered a Sun centered model of the universe which contrasted with the accepted Earth centered Ptolemaic model. Predictions of planetary positions from his model fared no better than the Ptolemaic model although they were somewhat simpler to calculate. Correct predictions awaited Keplers’ “Epitome astronomical Copernicanae, 1-3, De doctrina sphaerica” which was published in 1618. He derived the 3 laws of planetary motion and determined that planetary orbits are not perfect circles, they are ellipses!

Saturn (1.0) in Aquarius and Neptune (8.0 to 7.9) in Pisces are morning planets in April. The waning crescent Moon passes Saturn on the 15th and Neptune on the 17th. Jupiter will not be visible in April because it is on the other side of the Sun in Pisces and reaches solar conjunction on April 11. The waning crescent Moon passes Jupiter on the 19th, just before New Moon on the 20th.

On the 1st, Mercury (-1.0) is just above the western horizon in Pisces after sunset. Each succeeding night it will be higher until the 11th when it reaches greatest eastern elongation of 19° in Aries and drops to a magnitude of -0.1. The waxing crescent Moon passes less than 2° from dimming Mercury and even dimmer Uranus (5.8) in Aries on the 21st when all three are below brilliant Venus (-4.0) in Taurus. The waxing crescent Moon passes within 2° of Venus on the 23rd and 3° of Mars (1.0) in Gemini on the 25th.

• April Moon

April’s New Moon is in Aries on the 20th at 12:13AM EDT. It marks the start of Lunation 1241 which ends 29.49 days later with the New Moon of May in Taurus on the 19th at 11:55AM EDT. The New Moon will eclipse the Sun over the Pacific and Indian oceans. The Full Moon is in Leo on the 6th at 12:35AM EST. The April Moon is called the “Grass Moon” and “Egg Moon”, celebrating grass sprouting and the end of the hen’s molting season when egg production returns. It was called the “Seed Moon” in Medieval England and for Celts it was the “Growing Moon”. In China, it is the “Peony Moon” and Colonial Americans called it “Planter’s Moon”. Anishnaabe (Odawa and Ojibwe) first people recognize the April Moon as the “Boiling Sap Moon” (“Iskigamizige-giizis” in the western dialect and Skigamizige-giizis” in the eastern dialect).

The cultural teaching of the cycle of life and nature during the 4th Grandmother Moon of Creation is explained by Earth Haven Farm in Ontario as follows: “The fourth moon of Creation is Sucker Moon, when sucker goes to the Spirit World in order to receive cleansing techniques for this world. When it returns to this realm, it purifies a path for the Spirits and cleanses all our water beings. During this time we can learn to become healed healers.

Lunar Perigee distance (minimum lunar distance) is 228,645 mi. (57.69 Earth radiil) on the 15th at 10:24PM EDT. Lunar Apogee (maximum lunar distance) is on April 28 at 2:43AM EST when the Moon’s distance is 251,220 mi. (63.39 Earth radii). A The waning crescent Moon appears to pass Saturn on the 15th, Neptune on the 17th, and Jupiter on the 19th. A waxing crescent passes Mercury and Uranus on the 21st, Venus on the 23rd, and Mars on the 25th.