Moon in Motion

 

In the article, “Make the Most of January’s Total Lunar Eclipse” by Bob King he talks about the lunar eclipse that will take place in the morning on Wednesday, January 31st. King states that “the farther west you live, the higher the Moon will be in the sky and the more of the eclipse you’ll see.” He also includes images of the position of the moon as it moves through the different time zones.

 

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As you can see by the images he included you can see how the moon moves from East to West, while also tracking the time and what will be seen in the early sky.

The article can relate to the motion lecture tutorial that was done in class, specifically talking about the image that shows the rotation of a star in a night sky. In this case, the moon is still going counterclockwise because it’s going from East (i.e. New York) to West (i.e. California).

I found the article to be interesting and informative. Before this class I had not really paid attention on how objects move, but now what I’m taking away from this is the understanding of how objects move across our sky that we see in a daily basis.

 

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The Motion of the Moon

Coming soon on January the 31st, we will expect to see what NASA has called “a Super Blue Blood Moon” in the night sky. To many avid stargazers, this is a wondrous sight to have the chance to experience, and to the general populace, it is a prime opportunity to tear oneself away from whatever screen they are coupled with to witness a magnificent event in the physical universe. For those, such as myself, who are unaware of how such a rare event even occurs, the article I have chosen does an excellent job of detailing exactly what must happen. Three primary factors must be met for a moon to be considered a “Super Blue Blood Moon”:

  1. It Must be super: A supermoon is when our moon gets as close to the Earth as possible in its elliptical orbit, meaning that it appears larger than usual in the night sky.
  2. It Must Appear Blood-like: A blood moon occurs when the moon is completely covered by the Earth’s ‘umbra’, which is essentially Earth’s inner shadow. This, in turn, leads to a few hours of the moon looking bloodish-red, as only certain light rays are bouncing off of it as the Earth is blocking most of the sun’s rays.
  3. It Must be ‘Blue’: Blue in this context means that there have been two consecutive full moons in a single calendar month.

For all three of those criteria to be met at the same time is quite rare, and won’t happen again until 2037, so be sure to check it out around 5 o’clock on the 31th!

Source: https://www.space.com/39517-super-blue-blood-moon-2018-phases-explained.html

Now, as to the reason for choosing this article, I choose it because, in class, we were discussing quite a bit about how celestial objects appear and “move” from the perspective of an observer on Earth. The moon that will appear Wednesday night is a perfect encapsulation of this idea. When, for instance, we talked about the motion and position of the moon in relation to the sun and the Earth, we learned about how this three-way relationship can create certain aesthetic differences in the sky from our position here on Earth (perceiving the stars rotating around some central northern point, sun rising from the east and setting in the west, etc). Without this relationship, phenomena like supermoons and blood moons would not be able to physically occur.

As for the article itself, I enjoyed it quite a bit. I had always known and or heard about supermoons and blood moons before, however, I had never taken the necessary time to investigate why in which they happen. This article gave me that chance by outlining very clearly how these events happen and why they happen. Without this article and investigating what each was on my own I would probably still be unaware of the magnificent physical criteria required for their existence.

-Joseph Nontell

The Stars in the Sky

I found an article from sciencedaily.com entitled, “Farthest stars in Milky Way might be ripped from another galaxy.” The article explains that the 11 farthest known stars in our galaxy are 300,000 light years away, and that 5 of those may have been “ripped” from a different galaxy called the Sagittarius Dwarf. This galaxy orbits the Milky Way, and has lost much of its mass and stars over time. Scientists have figured out that the gravitational pull of our galaxy is literally tearing the Sagittarius Dwarf apart, and so some of the stars we see in the night sky are actually supposed to belong somewhere else.

The article relates to what we’ve been talking about in class because it explains at least one small part of what we see when we look out into space from Earth. From our point of view on this planet, all the other stars, planets, and other celestial bodies appear to orbit us. However, this is simply an illusion caused by the Earth’s rotation around the sun. From our point of view, the sun and stars appear to rise in the east and set in the west. Rising and setting is an illusion caused by the horizon. When the sun sets, it is no longer visible from our point of view because it has dipped below the horizon—meaning that the Earth is blocking us from seeing it. When it rises, it is no longer blocked by the Earth and we are able to see it again. Every celestial body appears to move at the same speed because of the Earth’s rotation; therefore, if the sun rises with a particular constellation, it sets with that constellation as well.

I thought that this was an interesting, informative article because it explains where a few of the billions of stars that we see in the night sky come from. Looking up at the sky at night is fascinating because space is so mysterious and infinite and there’s still so much that we don’t know about the universe. I thought it was weird that our galaxy could damage another so severely without even trying. It’s not like our galaxy planned to do it; both galaxies simply exist near each other and by chance just happened to have a profound effect on its entire structure. It’s so strange that celestial bodies are constantly interacting with each other like that throughout the universe.

UPDATE: (PERSONAL REFLECTION) I thought that the article was interesting and meaningful because it helped to reinforce some of the things that we learned in class about how celestial bodies appear to move in the sky. It also took what we learned about stars rising and setting one step further and explained exactly where a few of those stars came from, which I thought was interesting. Regardless of how far away these stars are or where exactly they came from, however, they all appear to move at the same speed, since this movement is an illusion caused by the Earth’s rotation, and the Earth rotates at a constant rate.

 

Does the North Star Ever Move?

http://earthsky.org/astronomy-essentials/north-star-movement

Sky wheeling around Polaris, the North Star.

The first conceptual objective, I can explain how astronomical objects (sun, planets, stars) appear to move in the sky, has been discussed frequently in class. In class we discussed that astronomical appear to move in the sky, but in fact, they are positioned. This illusion is caused by Earth’s rotation. The article I chose, “Does the North Star Ever Move?”, closely relates to the conceptual objective 1. Unlike every other star in the sky, the North Star, Polaris, appear to stay fixed in our sky. The time lapse photo shown above of the North Star and its surrounding stars would suggest that Polaris appears to slightly move. This is due to the rotation of Earth. Because the North Star is directly above the northern axis, it does not rise or set. In class, we also talked about certain stars that do not rise or set in the sky, these stars are called circumpolar stars. This article caught me by surprise. Even though the stars are fixed, Earth’s rotation appears to make them move. I was under the assumption that even with Earth’s rotation, the North Star has always stayed in the same location. This article suggests that the North Star, in fact, makes its own little movement around the sky’s north pole. Therefore, this article taught me something I was not aware of previously.

Christopher Stricker