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Wednesday, 24 October 2018 is the day of the October Full Moon. It is commonly known as the Hunter Moon and also as the Blood Moon or Sanguine Moon. This is the first full moon after the Harvest Moon, which is the Full Moon nearest the autumnal equinox. In most years, including 2018, the Harvest Moon comes in September, but in some years it occurs in October.

Sanguine is a curious word to attach to the Full Moon. Sanguine usually means “blood-red” and is associated with chalk of a reddish-brown colour, so called because it resembles the colour of dried blood. It has been popular for centuries for drawing and is preferred to common white chalk which only works on colored paper.

But “sanguine” (which comes via French from the Italian sanguigna and originally from the Latin sanguis) also means optimistic or positive, especially in an apparently bad or difficult situation, as in “She is sanguine about prospects for the upcoming elections.”

The Native Americans of the northern and eastern parts of the continent named this Full Moon that came at a time of leaves falling, deer fattened by summer growth and harvests, and concerns for getting game to store for the winter ahead. The appearance of “blood” in the naming comes from the hunting and also from the sometimes reddish appearance of the Moon when it first rises.

Some of the other names associated with this Full Moon are: Travel Moon, Dying Grass Moon, Moon of Falling Leaves (sometimes used in November), Moon When the Water Freezes, Blood Moon, Leaf Fall Moon, Basket Moon, Big Wind Moon, Shedding Moon, Winterfelleth (Winter Coming), Windermanoth (Vintage Month), Ten Colds Moon and the Moon of the Changing Seasons and Moon of the Changing Seasons

This is my birthday weekend and if I am lucky I will be able to look up at the sky in the dark hours before dawn and get a gift of some “shooting stars” that are part of the annual Orionid meteor shower.

The shower will peak overnight on October 21-22. The Orionid meteors do their thing every year between about October 2 and November 7. Hopefully, the sky will be cloudless and the almost full Moon won’t wipe out my view.

These meteors come from Earth passing through the dust cloud left behind by Halley’s Comet, and because we hit that dust head-on, these meteors are very fast. So named because they appear to come from the constellation Orion, they can be seen everywhere on Earth. Look east between midnight and dawn and find Orion who is easy to spot with the three aligned stars of his belt.

 

Orion

Moon

China is considering launching a fake “moon” into space. Chengdu, a city of 14 million people in China’s southwestern province of Sichuan, has announced plans to place a satellite in orbit by 2020 that is capable of reflecting sunlight. The plan is that this reflected light falling on its streets at night could replace street lights.

The satellite’s reflective coating could illuminate an area on Earth of up to 50 square miles, and the Chinese researchers claim their artificial moon will produce at least eight times more light than the real moon.

Hopefully, the Chinese have looked at a similar Russian project. Those researchers planned to use orbiting mirrors to light up cities in Siberia. They tried out a 25-meter mirror to illuminate a three-mile wide patch of land, but during its first orbit the craft was destroyed following a collision in space and the plan was abandoned.

Iapetus and Saturn

Iapetus, a moon of Saturn, could have its own moonmoon – Image: NASA

I write here frequently about our Moon. Stars are orbited by planets. Planets are orbited by moons. But what if a moon has something orbiting it?

Juna Kollmeier at Carnegie Observatories in Pasadena, California, and Sean Raymond at the University of Bordeaux, France calculated whether a moon orbiting a planet could have a moon of its own.

“We’re really just scratching the surface here with how we can use the absence of sub-moons to figure out our early history,” Kollmeier told Gizmodo. “I’m just super excited that people are interested in this and I hope more work is actually done with it.” Her research into the matter is still in its early stages, and it has still yet to be reviewed by other scientists, but it could potentially lead to some huge discoveries.

So far, the moon of a moon has no formal name. But we’ll need one when we finally spot one. Some names have been suggested: the rather boring and somewhat demeaning”submoon,” “mini-moon” (very close to Minnie Mouse) and the whimsical “moonmoon.”

Who gets to decide? The IAU, International Astronomical Union, is the body responsible for giving celestial objects their official names.

Earth certainly does not have any moonmoons.

Moonmoons could occur when the large moon is quite large, and the small moon is quite small, and both are sufficiently far away from the host planet. If a moon is close to the mother planet, the moonmoon could get sent to its destruction by the planet’s tidal forces.

If they do exist, it would be at the edges of our solar system or more likely beyond in some place we have not closely observed.

The Harvest Moon and Hunter’s Moon are the traditional names for the Full Moons occurring in autumn, usually in September and October, respectively. These two names go back to the early 18th century.

The Harvest Moon is the Full Moon closest to autumnal equinox. This year it became full in the early morning today, September 25, 2018. The Hunter’s Moon is the Full Moon that follows the next month.

Coincidentally, or apocryphally, some Native Americans also referred to this Full Moon as a hunting moon. Indian tribes of eastern and northern North America had as diet staples corn, pumpkins, squash, beans, and wild rice, and of which would normally be ready by this Full Moon. The Corn Moon was another Native American name for this Full Moon.

In 2010, the Harvest Moon occurred on the night of the equinox itself for the first time since 1991. Most years, the Harvest Moon is in September though it can be in October.

There are other names for autumn Full Moons: Nut Moon, Mulberry Moon, Gypsy Moon, Singing Moon, Barley Moon, Barley Moon, Elk Call Moon and Fruit Moon.

I know that many people think of the Harvest and Hunter Moons as being more orange-tinged. That fits in nicely with autumn tree colors and Halloween decorations, but really the Moon will not appear any more orange or red this season than it will during the year when there is enough atmosphere/pollution to add some color to our view. Also, the tilt of the Earth after the equinox gives a warmer color of the moon shortly after it rises. But it is an optical illusion. When the Moon is low in the sky, we are looking at it through more atmospheric particles (including pollution) than when the moon is overhead. All of that scatters the blue light but allows the reddish component of the light to travel a straighter path to your eyes.

And that low hanging Moon, to our eyes, is also perceived as being larger than one that is high in the sky. This is known as a Moon Illusion.

The Full Moons of September, October and November as seen from the northern hemisphere correspond to the full moons of March, April and May as seen from the southern hemisphere.

Dark matter bothers me. It also bothers scientists.

Galaxies don’t rotate by the same physics that we know and understand. Scientists noticed that stars at a galaxy’s edge rotate faster than expected. How can we explain that? There must be matter that is invisible to us that is there.

In 1998 and the Hubble Space Telescope observations of a very distant supernovae showed that a long time ago the universe was actually expanding more slowly than it is today. We once believed that gravity was causing the slowing expansion of the universe, but this showed that it was accelerating.

expansion of universe

A diagram reveals showing the rate of expansion since the universe’s birth 15 billion years ago. The curve changes noticeably about 7.5 billion years ago, when objects in the universe began flying apart at a faster rate. Astronomers theorize that the faster expansion rate is due to a mysterious, dark force that is pulling galaxies apart. Credit: NASA/STSci/Ann Feild

Astronomers know more about what dark matter is not than what it actually is. Roughly 68% of the universe is dark energy. Dark matter makes up about 27%. The rest is, well, everything on Earth. This “normal matter” is less than 5% of the universe. Actually, that hardly makes it qualify as the”norm.”

Most of the universe is made up of dark energy, and that mysterious force drives the accelerating expansion of the universe. The next largest ingredient is dark matter, and that only interacts with the rest of the universe through its gravity.

At one time, the theory was that MACHOs (Massive Compact Halo Objects) was the cause.  A MACHO, such as a brown dwarf, would be so massive that it would bend light around them. We know they exist, and we know they are out there, even though they are too dark for us to see. But this theory fell out of favor because there are not enough of them to make the galaxy-rotation math work.

Astrophysicists next came up with the WIMP (Weakly Interacting Massive Particles – the scientists do have a sense of humor). Maybe the universe is full of very small things we can’t see.

And maybe dark matter is made up of a different object we have never observed. One candidate is the neutralino.

We keep looking. The Large Hadron Collider, one of the most expensive science experiments ever built, is looking, but hasn’t found them.

But we do know that the universe is “heavier” than what we can see.

There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.
– Hamlet (1.5.167-8)

Dark matter doesn’t keep me up at night. But it did bother Alvy in the film Annie Hall.

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