The Schickard Crater. Gay Boyle photo

Backyard Astronomer: Our Glorious Moon

Gary Boyle

Stargazing is a wonderful, peaceful pasttime that anyone can enjoy. From planets to star clusters, galaxies to nebulae, the night sky is a treasure chest of celestial delights. Although astronomy and star gazing are traditionally done in the dark countryside, our glorious moon can be enjoyed from the city as well.

The moon was created about 50,000 years after the earth formed, 4.5 billion years ago. After the sun was created fine dust particles began sticking together, creating larger sand sized pieces. The “snowball” effect continued as more stuff clung together and built up to rock, boulder and small asteroid size.

Over the next few hundred million years this process formed about 100 baby planets call planetesimals. Like a cosmic demolition derby, they orbited the sun at different speeds and directions. One such body called Theia measuring the size of Mars, or half that of earth, hit our world with a glancing blow causing its tilt and ejecting molten rock into space. Like the rings of Saturn, the molten debris formed a ring around our planet and started to coalesce to what we see today.

Back then, the moon was only 20,000 kilometres away compared to its average 386,000-kilometre orbit. The moon is still moving away from us at the width of a golf ball per year.

As the molten moon was slowly cooling, lighter material rose to create a thin semi-smooth crust. The later heavy bombardment (LHB) lasting tens of millions of years showered the earth and moon as well as other planets with asteroids and comets. Early earth looked like the moon does today. Some massive asteroids fractured the thin lunar surface and allowed molten lava to float up and flood certain areas. These are the lunar maria that appears as the darker smoother regions.

The close distance of our two worlds creates a “tidal lock” which allows us to see roughly one side of the lunar surface. The so-called “dark side of the moon” is simply the opposite side that earth does not see except for the Apollo and other missions that have mapped this side in great detail. Except for about five days of the moon’s 29.5-day orbit, we see our natural satellite at various phases.

Through the eyepiece of a telescope, you can observe craters measuring only a few kilometres across. From night to night, long and short shadows produced by the sun, provide a slightly different face. The “terminator” is the dividing line between the lit and unlit areas, produces dramatic shadows. When doing terrestrial photography, the full moon will accent your portrait of distant mountains or trees during twilight but is the worst time to view with a telescope. Craters appear as circles without depth.

And on the topic of photography, the moon is bright enough to be imaged through a telescope. Unlike long exposures of constellations and other fainter objects where a telescope motor drive is needed to ensure pinpoint stars, the bright moon requires extremely short exposures. There are now adaptors that allow you to attach your smartphone to the telescope’s eyepiece.

Until next time, clear skies.

Known as “The Backyard Astronomer”, Gary Boyle is an astronomy educator, guest speaker and monthly columnist for the Royal Astronomical Society of Canada. He has been interviewed on more than 50 Canadian radio stations and local Ottawa TV. In recognition of his public outreach in astronomy, the International Astronomical Union has honoured him with the naming of Asteroid (22406) Garyboyle. Follow him on Twitter: @astroeducator or his website: www.wondersofastronomy.com

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Cranbrook city hall.
Cranbrook construction values continue to soar despite pandemic

The City of Cranbrook is on pace to finish the year with… Continue reading

RCMP
Crime severity index shows an increase in Cranbrook crime

Statistics Canada has released the latest index, which is based on police-reported incidents

Cranbrook city hall.
Cranbrook maps out investment attraction strategy for economic development

Cranbrook is eyeing a number of industrial sectors identified in an investment… Continue reading

test tube with the blood test is on the table next to the documents. Positive test for coronavirus covid-19. The concept of fighting a dangerous Chinese disease.
Interior Health records third COVID-19 death

A new community outbreak was reported at Okanagan Men’s Centre in Lake Country

NAV CANDA is considering closing its station at the West Kootenay Regional Airport. Photo: Betsy Kline
Nav Canada considering closing station at West Kootenay Regional Airport

The organization is conducting a service review at Castlegar’s airport

A woman wears a face mask and plastic gloves while browsing books as a sticker on the floor indicates a one-way direction of travel between shelves of books at the Vancouver Public Library’s central branch, after it and four other branches reopened with limited services, in Vancouver, on Tuesday, July 14, 2020. (THE CANADIAN PRESS/Darryl Dyck)
B.C. reports 234 new COVID cases, 1 death of senior who had attended small birthday party

Roughly 5,700 people are isolating due to being exposed to a confirmed case

A nurse performs a test on a patient at a drive-in COVID-19 clinic in Montreal, on Wednesday, October 21, 2020. THE CANADIAN PRESS/Paul Chiasson
Interior Health reports seven more COVID-19 cases

Eighty-nine cases remain active, none of whom are currently hospitalized

Burnaby RCMP responded to a dine-and-dash suspect who fell through a ceiling in March 2020. (RCMP handout)
VIDEO: Suspected dine-and-dasher falls through ceiling of Burnaby restaurant

A woman believed to be dashing on her restaurant bill fell through the kitchen ceiling

A can of Canada Dry Ginger Ale is shown in Toronto on Thursday Oct. 29, 2020. The maker of Canada Dry Ginger Ale has agreed to pay over $200,000 to settle a class-action lawsuit launched by a B.C. man who alleged he was misled by marketing suggesting the soda had medicinal benefits. THE CANADIAN PRESS/Joseph O’Connal
B.C. man’s lawsuit over marketing of Canada Dry ginger ale settled for $200K

Soda’s maker, Canada Dry Mott’s Inc., denied the allegations and any liability

Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Vancouver Island-based Wilson’s Transportation has expanded to fill some of the routes left unserviced by Greyhound as of Nov. 1, 2018. (Black Press files)
B.C. bus companies say they need help to survive COVID-19

Like airlines, motor coaches have lost most of their revenue

A deer was spotted in October 2020 in Prince Rupert, B.C., with a bright pink yoga ball stuck in its antlers. (Kayla Vickers/Chronicles Of Hammy The Deer Official Page)
Hammy 2.0? Prince Rupert deer spotted with bright pink yoga ball stuck in antlers

The BC Conservation Officer Service is aware of the deer roaming around the city

RCMP. (Phil McLachlan - Black Press Media)
Kelowna Mountie hit with 2nd lawsuit in 2 months for alleged assault

Const. Julius Prommer is accused of breaking a woman’s knee during while responding to a noise complaint

Most Read