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Originally posted by Alienmojo
However, confused or not, the op is not lying. He is calling it as he sees it and has come on here to get more information. NOT to be insulted at every turn. This is the reason why I no longer start threads. I hate the ridicule.
Courtesy: NASA/Goddard Space Flight Center Scientific Visualization Studio
The animation archived on this page shows the geocentric phase, libration, position angle of the axis, and apparent diameter of the Moon throughout the year 2011, at hourly intervals. The Current Moon image is the frame from this animation for the current hour.
This marks the first time that accurate shadows at this level of detail are possible in such a computer simulation. The shadows are based on the global elevation map being developed from measurements by the Lunar Orbiter Laser Altimeter (LOLA) aboard the Lunar Reconnaissance Orbiter (LRO). LOLA has already taken more than 10 times as many elevation measurements as all previous missions combined.
Note that a crescent moon has nothing to do with Earth’s shadow on the moon. The only time Earth’s shadow can fall on the moon is at full moon, during a lunar eclipse. There is a shadow on a crescent moon, but it’s the moon’s own shadow. Night on the moon happens on the part of the moon submerged in the moon’s own shadow. Likewise, night on Earth happens on the part of Earth submerged in Earth’s own shadow.
The direction in which the "horns" (the points at the intersection of the two arcs) face indicates whether a crescent is waxing (also young, or increasing) or waning (also old, or decreasing). Eastward pointing horns (pointing to the left, as seen from the Northern hemisphere) indicate a waxing crescent, whereas westward pointing horns (pointing to the right, as seen from the Northern Hemisphere ) indicate a waning crescent. Note that the directions the horns point relative to the observer are reversed in the Southern Hemisphere.
The angle of tilt is determined by where the observer is (what latitude.)
The orientation of the Moon's crescent also depends on the latitude of the observation site: close to the equator, an observer can see a smile-shaped crescent Moon.
The orientation of the Moon's crescent also depends on the latitude of the observation site. Close to the equator, an observer can see a boat Moon.
The Moon orbits at an angle that varies between 18 and 28 degrees relative to the equator. If you lived at 28 degrees latitude or lower (southern Florida or further South), the Moon could be located directly overhead. Or, if you lived in the Southern hemisphere above 28 degrees South latitude, you'd occasionally see the Moon directly overhead (Brazil, Peru, etc).
The Sun's position travels at an angle of 23 degrees relative to the equator. The Moon probably started out orbiting along the Earth's equator, but the Sun's gravity has pulled the Moon to within 5 degrees of it's own plane. That means the Moon's orbit varies between -5 and +5 degrees of the Sun's plane (actually, the plane of the Earth's orbit around the Sun).
Originally posted by luxordelphi
The moon should be tilted a lot more like a backwards C instead of like a U in Las Vegas. The moon tilted like a U is something that happens on the equator.
Las Vegas is not on the equator or even in the tropics. Las Vegas is in the mid-latitudes.
Is the Moon seen as a crescent (and not a "boat") all over the world?
Recently a friend of mine visited the country of Bali in Africa. She claims that because that country is south of the equator, the Moon, instead of having a crescent shape during certain phases, will actually have a "boat" shape. Is she pulling my leg ?? Isn't the crescent shape seen the whole world over ??
Kristine: Your friend is right; the orientation of the crescent moon depends on the latitude of the person observing it (the size of the crescent, however, is the same wherever you are).
This means that if the concave part of the crescent points "left" in North, it will point "right" in the South. Since the transition from a "left" pointing crescent to a "right" pointing one must be smooth, we require that the Moon be a "boat" instead of a crescent at the equator.
Originally posted by Uncinus
reply to post by bhornbuckle75
Actually that's a computer simulation. It's an idealized version of what you would see, and ignores the rotation of the earth.
Courtesy: NASA/Goddard Space Flight Center Scientific Visualization Studio
edit on 9-11-2011 by bhornbuckle75 because: Something something
Originally posted by luxordelphi
reply to post by Soylent Green Is People
The graphic you present showing the 'Moon's Winter Path' is no good because it doesn't have a sun. The graphic itself is credited to the Goddard Space Flight Center so I'm not faulting you for this. The graphic is also used in this link:
Originally posted by luxordelphi
The graphic you present showing the 'Moon's Winter Path' is no good because it doesn't have a sun. The graphic itself is credited to the Goddard Space Flight Center so I'm not faulting you for this.
During summer in the northern hemisphere, we are tipped away from the Moon's orbit, putting the Moon lower in the sky and creating more of a crescent. During winter in the north, we are tipped toward the Moon's orbit, putting the Moon higher in the sky and creating more of a boat.
Originally posted by luxordelphi
...The first diagram you present is relevant to an observer in outer space. "The angle of tilt is determined by where the observer is (what latitude.)" That's a quote from my previous post. The phase is always the same and is independent of the location of the observer but the tilt is not. I'm not talking about any tilted orbits. I'm talking about the tilt of the moon which is bound by the geographical, latitude, location of the observer.
Originally posted by luxordelphi
I appreciate also the desire to want to try and explain this within existing parameters, however, just like the planetarium I mentioned above, it can't be done. It can only be done if the established order has changed and that's how they did it.
Originally posted by luxordelphi
...I appreciate the thought and effort you have put into your reply to me. The boat, smile moon (the tilt of the light on the moon) is not a winter phenomena. There are plenty of illustrations from all over the world, some of which I have supplied, to show that this phenomena does not know a season. The 'Winter Moon Path' theory is no theory. The example I gave from 43 degrees N latitude happened in March.
Originally posted by luxordelphi
...Las Vegas is in the middle latitudes. It is not 'near' the equator. The tropics end at 23.5 degrees N and S of the equator. There is not a 'mostly at the bottom' or 'more pronounced' or 'kind of like' to explain this. There is only the location - latitude - of the observer. These are hard numbers...
Therefore the equator would be 23° south on winter nights, and Las Vegas would only be at 13° north of that ecliptic.
Originally posted by luxordelphi
I appreciate also the desire to want to try and explain this within existing parameters, however, just like the planetarium I mentioned above, it can't be done. It can only be done if the established order has changed and that's how they did it.
Originally posted by luxordelphi
...I appreciate also the desire to want to try and explain this within existing parameters, however, just like the planetarium I mentioned above, it can't be done. It can only be done if the established order has changed and that's how they did it.
An orbit whose evolution is so sensitive to minor changes in the orbiting object's position and/or velocity with respect to other gravitating bodies that it is essentially unpredictable. Saturn's moons Pandora and Prometheus have chaotic orbits.
You might be surprised to learn that the Earth's orbit round the Sun, like those of other planets,is chaotic.
When the equations of motion of a system cannot be solved by mathematics, a possible alternative is to solve them using a digital computer . Although such a numerical integration provides less insight than a mathematical solution,it is one of the most powerful tools in modern dynamical astronomy.
In 1988, Sussman and Wisdom produced integrations using the Orrery which revealed that Pluto's orbit shows the tell-tale signs of chaos, due in part to its peculiar resonance with Neptune.
If Pluto's orbit is chaotic, then technically the whole Solar System is chaotic, because each planet, even one as small as Pluto, affects the others to some extent through gravitational interactions. But we now realise that although chaos means that some orbits are unpredictable, it does not necessarily mean that planets will collide - chaotic motion can still be bounded.
Laskar's work showed that the Earth's orbit (as well as the orbits of all the inner planets) is chaotic and that an error as small as 15 metres in measuring the position of the Earth today would make it impossible to predict where the Earth would be in its orbit in just over 100 million years' time.
Laskar's results still have to be confirmed by integrating the full equations of motion, but this will have to wait until the next generation of supercomputers arrives. Meanwhile, we can take comfort from the fact that his work does not imply that orbital catastrophe awaits our planet, only that its future path is unpredictable. It seems likely that the Solar System is chaotic but nevertheless confined, although we have yet to prove it.More than 300 years after the publication of Newton's Principia, we are still struggling to understand the full implications of his square law of gravity. We have begun to view our system of chaos in a light that is revealing the true intricacies of its majestic clockwork.
Trojan asteroid: NASA has discovered that Earth has an asteroid companion traveling just ahead of our planet as it orbits the sun.
"This one has behavior much more interesting than I thought we would find," study co-author Martin Connors, an astronomer at Athabasca University in Canada, told SPACE.com. "It seems to do things not seen for Trojans before. Still, it had to have some kind of extreme behavior to move it far enough from its Lagrangian point to get within our view."
The fact that 2010 TK7's behavior is chaotic enough to take it quite far from its rather stable Trojan point suggests it is only marginally trapped there, having perhaps only recently been disturbed from its original position.
The only way for a planet to have two moons is for them to have very little effect on one another. If they're large enough to affect each other, then you have a three-body system, and it's nearly impossible for a three-body system to be gravitationally stable.