Fact Friday – The Moon

“Mom, what would happen if we didn’t have the moon?”

Don’t you love how kids become little dehydrated philosophers as soon as it’s bedtime?

But it’s a pretty good question cause the only answer I could come up with on the spot was that it has an effect on the tides. Give me a small break though, he’s had a cough and kept me awake for the past two nights. I’m exhausted.

So we googled what would happen if the moon blew up and apparently there are many ways the Moon actually does affect the Earth. Destroying it would be a catastrophe, but would also change our world in some incredibly interesting ways according to an article on Forbs.com

Destroying the Moon would send debris to Earth, but it might not be life-exterminating. Imagine a weapon so deadly it could gravitationally unbind the Moon, blowing it apart. It would take a medium-sized asteroid’s worth of antimatter to do it (about a kilometer in diameter), and the debris would spread out in all directions. If the blast were weak enough, the debris would re-form into one or more new moons; if it were too strong, there would be nothing left; of just the right magnitude, and it would create a ringed system around Earth. Over time, those lunar fragments would de-orbit thanks to Earth’s atmosphere, creating a series of impacts.

The night sky would be naturally much brighter. Once the Moon and all its remnants were gone, the second-brightest object from Earth’s sky would be completely gone. While the Sun is naturally 400,000 times brighter than even the full, perigee Moon, the full Moon is again 14,000 times brighter than the next-brightest object in the sky: Venus. When you look at the Bortle Dark-Sky Scale, a full Moon can take you from a “1” — the most pristine, naturally dark sky possible — all the way up to a 7 or 8, washing out even bright stars. Without a Moon, there would be no natural impediments to pristine, dark skies every night of the year.

Eclipses would be no more. Whether you’re talking solar eclipses — partial, total or annular — or lunar eclipses, where Earth’s natural satellite passes into our shadow, we would no longer have eclipses of any type. Eclipses require three objects to be aligned: the Sun, a planet and a planet’s moon. When the moon passes between the Sun and a planet, a shadow can be cast on the planet’s surface (total eclipse), the moon can transit across the Sun’s surface (annular eclipse), or it can obscure just a fraction of the Sun’s light (partial eclipse). But without a moon at all, none of these could occur. Our only natural satellite would never pass into Earth’s shadow if it didn’t exist, putting an end to eclipses.

The length of a day would remain constant. You might not think about it much, but the Moon exerts a tiny frictional force on the spinning Earth, causing our rotation rate to slow down over time. We might only lose a second here or there over many centuries, but it adds up over time. Our 24 hour day was only 22 hours back when dinosaurs roamed the Earth, and was under 10 hours a few billion years ago. In another four million years, we won’t need leap days any longer in our calendar, as the rotation rate slows and the length of a day continues to get longer. But without a Moon, all that would cease. It would be 24 hour days every single day to come, until the Sun itself ran out of fuel and died.

Our tides would be tiny. High tide and low tide presents an interesting, vast difference for those of us who live near the coast, particularly if we’re in a bay, sound, inlet, or other area where water pools. Our tides on Earth are primarily due to the Moon, with the Sun contributing only a small fraction of the tides we see today. During full moons and new moons, when the Sun, Earth and Moon are aligned, we have spring tides: the largest differences between high and low tide possible. When they’re at right angles, during a half Moon, we have neap tides: the smallest such differences. Spring tides are twice as large as neap tides, but without our Moon, the tides would always be the same paltry size, and only a quarter as big as today’s spring tides.

Our axial tilt would be unstable. This is an unfortunate one. Earth spins on its axis, tilted at 23.4° with respect to our orbital plane around the Sun. (This is known as our obliquity.) You might not think the Moon has much to do with that, but over tens of thousands of years, that tilt changes: from as little as 22.1° to as much as 24.5°. The Moon is a stabilizing force, as worlds without big moons — like Mars — see their axial tilt change by ten times as much over time. On Earth, without a Moon, its estimated that our tilt would possibly even exceed 45° at times, making us a world that spun on our sides. Poles wouldn’t always be cold; the equator might not always be warm. Without our Moon to stabilize us, ice ages would preferentially hit different parts of our world every few thousand years.



Five extra Fabulous Facts

The Earth’s rotation has slowed down due to the Moon’s gravity, long ago –  days were much shorter and rotation was faster.

Mons Huygens is the tallest mountain on the Moon, it is 4700 metres tall, just over half the height of Mt Everest (8848m)

According to scientists, the Moon was formed as a result of a giant impact or giant whack of Earth with Mars sized planet, which resulted in the Moon.

A lunar eclipse, lasts longer than a solar eclipse because Earth’s shadow is so much longer.  In lunar eclipse, earth passes between Sun and the Moon.

Soviet space probe Luna 2 was the first probe to reach the Moon, in 1959, which crash-landed on the Moon.  The first probe, missed the Moon by 3,000 miles, which is Luna 1.

Any other interesting facts you can share with us?


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