Moons orbit planets, planets orbit the sun. Round and round they go forever locked in gravitational harmony. Sunrise, sunset, new moon, full moon, every day a 24 hour certainty. Foundations so fundamental we take them for granted. Not so fast – days haven’t always been 24 hours. Truth is, days are getting longer.
New astronomical research dubbed astrochronology suggests that recently as 1.4 billion years ago Earth completed a day in 18 hours. Science credits interaction of Earth/Moon tidal forces for lunar orbit spiraling away from Earth at 1.5 inches a year.
Gravity is a cosmic wonder, proximity of mass dictates rate of rotation. 18 hour day Earth was driven by a vastly closer Moon. Over time rotation slows as the Moon spirals away. Less pull, less spin, longer days.
Trumpeting moon talk announced the arrival of 2018. Tonight a behemoth supermoon hangs in the sky – of 13 full moons and 14 lunar perigees in 2018, this is the closest full moon and lunar perigee alignment of the year. ( A supermoon happens when the full moon coincides with the moon’s closest approach to Earth in its orbit. ) Tonight is the second of 3 consecutive supermoons.
Technically close and bright as tonight’s supermoon shines, January 31, 2018 promises to steal the show. This third supermoon in a row is a blue supermoon (second full moon in a calendar month ), one that will pass through Earth’s shadow, delivering a full lunar eclipse.Follow this link for eclipse in your time zone – http://earthsky.org/tonight/super-blue-moon-eclipse-on-january-31#calculator
The Moon – steeped in mythology, banded by superstition, monitor of passing time. Comforting phases wax and wane, from crescent sliver to rotund glory, moon shadows rule the night. On September 30, 2016 a shadowless Black Moon will pass unnoticed in the Western Hemisphere.
When a second new moon falls in a month it answers to Black. All new moons are indistinguishable from the night sky – unseen because lunar orbit briefly bounces sunlight off the far side of the moon. They may be dark, but only become black every 32 months or so when a second lunar cycle begins in the same month.
There are more names for our Moon, than all identified/named moons orbiting planets in the solar system. (Great link below to 182 identified/named moons of those planets, followed by moonconnection.com for all things lunar, and another link to ponder Black Moon ) Add black moon to the list, then listen to my favorite moon song –
Tonight’s’ full moon sets the stage for a Blue Moon on July 31st. “Blue Moon” refers to a second full moon in a calendar month. Our moon follows a 19 year loop called the Metonic Cycle – every 19 years phases of the moon recur on or near the same calendar date. Nineteen years has 228 months with 235 full moons, meaning 7 of those 228 months have a blue moon. Sometimes February’s short number of days produces 8 blue moons in a Metonic Cycle (February 2018 won’t have a full moon, pushing the extra moon to another calendar month)
Popular use of the term is credited to a 1946 issue of Sky and Telescope magazine. Author James Hugh Pruett penned an article “Once In A Blue Moon”, Pruett inadvertently screwed up finer details when referencing the 1937 Maine Farmer’s Almanac – nevertheless “once in a blue moon” was born.
The Maine Farmers Almanac described blue moons as an extra full moon in a “season”. Each season – spring, summer, fall, winter typically has 3 full moons, when a 4th happens, the 3rd moon of that season becomes the blue moon. By this rule the next one falls on May 21, 2016. Although two distinctly different definitions exist, most people subscribe to the monthly club.
It’s possible to have 2 blue moons in a calendar year, the next time is January and March of 2018, followed by January and March 2037. Sometimes a rare year has both monthly (2 full moons in a month) and seasonal (3rd full moon of 4 in a season) – don’t hold your breath, it will be 2048 before the monthly in January, seasonal in August.
We visualize our Moon as a lifeless constant. The polite ebb and flow of lunar cycles, familiar photographs of craters and desolate landscapes. Nary a thought to what might lurk beneath that comfortably stark surface. Does it have a hot core like Earth, or did it once froth with geologic intensity?
In 1971, Apollo 15 astronauts captured images of a lunar anomaly dubbed Ina- by all appearances, the aftermath of volcanic eruption. Science knows the adolescent moon was turbulent – much of the lunar surface is covered in basaltic flows, features of the “man in the moon” were created by seething lava. Science believed lunar vulcanism ceased a billion years ago – Ina raised eyebrows, presenting itself as mysteriously recent.
NASA’s Lunar Reconnaissance Orbiter (LRO) has identified 70 sites similar to Ina, anomalies called irregular mare patches (IMP’s). Lightly cratered, these features have rewritten the geologic timeline of conventional thinking. Consider the possibility of volcanic eruptions 50-100 million years ago. Lunar eruptions during the time of dinosaurs might not seem like a remarkable ponder – I assure you, the leap from a billion to 50 million years is an astounding geologic mind blower.
The next time you catch sight of the moon, smile and ponder the possibility of a churning molten core under all that moonlit familiarity.
A solar eclipse happens when the moon passes between Earth and the Sun. The moon has “phases” as it travels in a wobbly orbit around Earth. The “light of the Moon” is really just sunlight reflecting off the lunar surface. Depending where the Moon is in relation to the Sun, this light appears to us as new moon, crescent moon, quarter moon, half moon, full moon and so on – the moon orbits Earth once every 29 1/2 days, hence our lunar cycle.
A “new Moon” can’t actually be seen from Earth because the illuminated side points away from us. A solar eclipse can only happen during the new moon phase, and only when the wobbly moon orbit lines up between Earth and the Sun, as to caste a shadow – this is a solar eclipse. Because the Moon’s orbit is tilted 5 degrees to Earth’s orbit around the Sun, the “shadow” usually misses Earth. A couple of times a year the shadow falls on our planet, depending on the angle of orbit and global location, this translates to varying degrees of eclipse.
On October 23, a partial eclipse will dazzle those inclined to notice – if you reside in the “red zone”, click on the link below the graphic for optimum viewing times and duration.