August Skies

by Dick Cookman

August 1, 2024

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

Focus Constellations: Ursa Major, Draco, Ursa Minor, Camelopardalis, Perseus, Cassiopeia, Cepheus, Andromeda, Pegasus, Cygnus, Lyra, Aquila, Ophiuchus, Hercules, Corona Borealis, Bootes

Comet Journals

Comet C/2023 A3 (Tsuchinshan-ATLAS) is a 8th magnitude comet circling through Sextans. It may brighten drastically when approaching perihelion passage in late September. It may briefly attain naked eye visibility at 1st magnitude. The comet passes perigee (closest to Earth) on October 12, lighting up the western evening sky. It will then circle through the summer triangle in Aquila, Cygnus, and Lyra for the next 6 months while retreating to its origin in the Oort Cloud.

Comet 13P/Olbers (2024) is a short period 7th magnitude comet in Ursa Major and Coma Berenices in August. It passed through perihelion on June 30 and was closest to Earth on July 20.

Mars Landers

The Perseverance rover found an unusual rock in a fossil river channel within the “Bright Angel” region of Mars’ Jezero Crater on July 18. The rock contains spots with black halos similar to those found in Earth rocks and formed when chemical reactions involving hematite release iron and phosphate, causing black halos to form. The reactions are utilized as an energy source by microbes. Previous discoveries by the Martian rovers have uncovered copious evidence that billions of years ago conditions on the red planet may have been favorable to life and numerous organic molecules which may be evidence of pre-existing life have also been found. No current lifeforms have yet been found on Mars, but extremophile lifeforms that exist on Earth have been subjected to Martian conditions and survived. Some lichens, fungi, mosses, and cyanobacteria have even proliferated under the extremely tough conditions that exist on Mars! Billions of years ago, cyanobacteria transformed an inhospitable Earth atmosphere deficient in oxygen and containing a variety of toxic molecular components into one providing the basis for life as we know it. Never mind that the transformation caused the greatest extinction in the planet’s history when a vast array of anaerobes which dominated the first two billion years of planetary evolution were almost wiped out.

Meteor Showers

August meteor showers in August include the famous Perseids, the Kappa Cygnids, and the Alpha Aurigids. The latter two are relatively minor in comparison to the Perseid Meteor Shower which highlights the evening of the 1st quarter Moon on the 12th. The best time to view the shower is the predawn hours of the 12th and 13th after moonset when Earth plunges face first through a stream of comet debris.

• August 12: Perseids. Active July 15-August 24. Radiant 3h16m +58°, ZHR 100, 59 km/sec. 1st Quarter Moon. Progenitor: Comet 109/P Swift-Tuttle.
• August 17: Kappa Cygnids. Active August 3 – 25. Radiant 19h4m 59°, ZHR 3, 25 km/sec. Waxing Gibbous Moon. Progenitor: Asteroid 2008 ED69?.
• August 31: Alpha Aurigids. Active August 25 – Sept. 8. Radiant 5h36m +42°, ZHR 7, 23 km/sec. Waning Crescent Moon. Progenitor: Comet C/1911 N1 Kiess.

Planet Plottings

Mercury (1.2 to 0.7) and Venus (-3.8) in Leo, Saturn (0.8, in Aquarius), and Neptune (7.8, in Pisces) are evening planets in the western sky in August. On the 5th, the waxing crescent Moon passes Venus and, on the 6th, Mercury passes Venus after visiting the Moon the night before. All three hug the western horizon after sunset with Mercury briefly visible on the 1st before falling into sunset’s glare as it approaches inferior conjunction with the Sun on the 18th. The waning gibbous Moon passes Neptune on the 20th. Saturn (0.8, in Aquarius) rises about 10PM EDT on the 1st and before sunset by the end of the month. the waning gibbous Moon passes the ringed planet on the 20th.

Early morning skies display Jupiter (-2.09 to -2.1), Uranus (5.8 to 5.7), and Mars (0.9 to 0.7) in Taurus in the eastern sky before sunrise. Mars and Jupiter are less than one half of a degree apart on the 14th. The waning gibbous Moon passes Uranus on the 25th and the waning crescent Moon passes Jupiter and Mars on the 27th.

August Moon

August’s New Moon is in Cancer on the 4th at 7:13AM EDT. The New Moon marks the start of Lunation 1257 which ends 29.51 days later with the New Moon of September in Leo on the 2nd at 9:56PM EDT. The Full Moon on the 19th occurs at 2:26PM EDT in Capricornus. It is a Blue Moon and a Supermoon and is known as the Sturgeon, Grain, or Green Corn Moon. This blue moon is the 3rd of 4 full moons in the summer season, and the supermoon occurs within 36 hours of one of the closest perihelions (minimum lunar distance) of the year when its proximity to Earth makes it appear larger and brighter than normal. Colonial Americans called it the “Dog Days Moon”. To the Celts it was the “Dispute Moon”, and the Chinese refer to it as the “Harvest Moon”. Medieval English thought of it as the “Corn Moon”, and the Anishinaabe (Odawa and Ojibwe) people of northern Michigan recognize it as “Manoominike-giizis (Ricing Moon). Ontario’s Earth Haven Farm presents cultural teachings explaining the cycle of life and nature of their 13 Grandmother Moons. “The eighth moon of Creation is the Thimbleberry Moon, when we honour the Thimbleberry which produces an abundance of fruit once every three years. It was one of the first plants put on Mother Earth, and its purpose is to protect the Sacred Circle of Life by allowing us to recognize and understand the teachings that come from the Spirit World.”

Lunar Apogee (maximum lunar distance) is on August 8 at 9:31PM EDT. Lunar distance is 251,840mi. (63.55 Earth radii). Lunar perigee is on Aug. 21. It is at 223,815 mi. (56.47 Earth radii) at 1:02AM EDT.