July 2025 Skies

BY: DICK COOKMAN

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

Focus Constellations: Ursa Major, Draco, Ursa Minor, Cepheus, Cassiopeia, Camelopardalis, Lynx, Leo Minor, Leo, Coma Berenices, Virgo, Bootes, Corona Borealis, Hercules, Lyra, Cygnus, Vulpecula

☄️Comets: Comet C/2023 A3 (Tsuchinshan-ATLAS) is on the Lyra/Hercules border and at 13th magnitude. It is departing to the Oort Belt or, if its orbit is hyperbolic and allows escape from the Sun, the great beyond.

First discovered in May, C/2025 K1 (ATLAS) is a 12th magnitude Oort Belt comet rising in Pegasus in the evening and moving into Vulpecula in July. Perihelion passage is on October 8 in Virgo when it may reach 8th magnitude. It is closest to Earth in late November.

🚀 Mars – What are the Rovers Up To?
Thirty years of discovery reveal evidence for almost 6000 exoplanets. Detailed information of other planets is pretty much restricted to Mars as numerous satellites, landers, and rovers provide a plethora of information about the red planet, too much to have been adequately analyzed by the limited number of scientists available.  A recent study in Nature Magazine states that lead study author Edwin Kite, a planetary scientist at the University of Chicago and a member of the Curiosity team, said that it appeared there were "blips of habitability in some times and places" on Mars, but allowed that these "oases" were few and far between. Although Mars is currently dry and cold, there is plenty of evidence that warm and wet conditions existed in the distant past. What happened? Edwin Kite proposes that, unlike Earth, Martian carbon cycling lacks copious vulcanism. On Earth, volcanoes recycle oceanic rocks and sediments when oceanic plates collide with each other and with continental plates. The rocks include carbonates, the long term storehouses of carbon from atmospheric CO2 which gets dissolved in the ocean. Limited carbon recycling by CO2 emitting volcanoes on Mars reduces the greenhouse effect. Earth is kept warm by the greenhouse effect. Without it, average temperatures on Earth would be ~45-50° lower. If you want to prevent excessive? greenhouse warming on Earth, stop vulcanism!

Or, on the other hand, you could interfere with transition from dissolved CO2 to carbonate rock in the ocean. It is an equilibrium reaction, too much of something on one side of the reaction forces the reaction to reverse. CO2 and water combine to produce bicarbonate (HCO3) and hydrogen ion. Bicarbonate reacts with dissolved calcium causing carbonate sediments to precipitate onto the seafloor. These are eventually lithified into carbonate rock which is fed to volcanoes by plate tectonics. Stop formation of carbonate rocks–– no carbon for volcanoes to spew back into the atmosphere. Problem solved! How to add bicarbonate and hydrogen ion and prevent carbonate formation? That is easy, increase erosion and weathering rates or dump in limestone (concrete?––thank the old time mobs with their concrete boots trying to save the planet). If you want questions answered, keep on studying Mars. Mars will provide.

🌟 Meteor Showers

The three best meteor showers in July are all southern hemisphere showers. The Pisces Austrinids (July 27) and the Alpha Capricornids (July 29) are both minor showers and the Delta Aquarids typically produce about 25 meteors/hour in exceptionally dark predawn skies. Expect up to 12 meteors/hour.

July 31: South Delta Aquarids, Active July 12-August 23, Radiant 22h36m -16°, ZHR 20, 41 km/sec., Waxing Crescent Moon, Progenitor: possibly a combination of Comet 96P and Asteroid 2003 EH1.

🪐 Planet Plottings

After sunset in early July, Saturn (1.0 to 0.8), and Neptune (7.9 to 7.8) rise together in Pisces in the east and can be seen throughout the night. Mercury (0.5 to 4.8) sets in Cancer in the western sky slightly before 8PM EDT and Mars (1.5 to 1.6) sets two hours later in Leo, Mercury is at greatest eastern elongation on the 4th when it is 26° from the Sun. The waxing crescent Moon passes Mercury on the 25th but the planet sets two hours earlier and is no longer visible as it approaches inferior conjunction on the 31st. Mars is visible throughout the entire month and sets after 9:00PM EDT as the waxing crescent Moon passes on the 28th, 4 days after New Moon.

Before dawn in July, binoculars reveal dim Neptune north of bright ringed Saturn. On the 6th, they will be separated by less than one degree. The waning gibbous Moon passes each on the 16th. Jupiter (-1.7 to -1.8) in Gemini rises about 5:00AM EDT on the 14th, well after the rising of sparkling Venus (-4.0 to -3.9) and much dimmer Uranus (5.8) which are higher in the southeastern sky in Taurus. The waning crescent Moon passes them respectively on the 21st and 20th.

🌚 July Moon

The New Moon of July in Cancer on the 24th at 3:11PM EDT introduces Lunation 1269 which ends 28.95 days later with the New Moon of August 22 at 2:06PM EDT.  The Full Moon on the 10th at 4:37PM EDT in Sagittarius is a Hay, or Thunder Moon. Colonial Americans called it “Summer Moon”. To the Celts it was “Moon of Claiming”, and it is “Hungry Ghost Moon” in China. Medieval English thought of it as “Mead Moon” and to Anishinaabe (Odawa, Potawatomi, and Ojibwe) people, it is Aabita-niibina-gitziis (Mid-Summer Moon) or Miin-giizis (Berry Moon).

In summer (Niibin), The constellation dominating southern skies represents the Anishinaabe Protecting Spirit/trickster, Nanaboujou. It rises before sunset in the southeast in Scorpius and sets about 1:00 or 2:00AM EDT in July. Anishinaabe stories about Nanaboujou play a central role in indigenous culture, teaching how to live appropriately. They are comparable to Christian parables. The following link is about Naniboujou and the Thunderbirds: https://www.reddit.com/r/Native_Stories/comments/13m91sc/naniboujou_and_the_thunderbirds/.

Cultural teachings of the Anishinabek Nation’s Mississauga branch by Ontario’s Earth Haven Farm include the 13 Grandmother Moons and the cycle of life: “The seventh moon of Creation is Raspberry Moon, when great changes begin. By learning gentleness and kindness, we may pass through the thorns of its bush and harvest its fruit, knowledge that will help in raising our families.”

The Moon is at Lunar Apogee (maximum lunar distance of 251,423 mi. (63.44 Earth radii) on July 4 at 10:29PM EDT. Lunar perigee is on July 20 at 9:55AM EDT. The Moon is at 228,690 mi. (57.70 Earth radii). The waning gibbous Moon passes Neptune and Saturn on the 16th. The waning crescent Moon passes Uranus on the 20th, Venus on the 21st, and Jupiter on the 22nd. The waxing crescent Moon passes Mercury on the 25th, almost 10 hours after New Moon and then passes Mars on the 28th.