Features of the Milky Way

¶ … features of the Milky Way Galaxy is Open Clusters or Galactic Clusters. There are about 1000 stars in the clusters and together there are approximately 20,000 clusters in the Milky Way. The largest concentration of the clusters is located in the main body or the plane of the galaxy. This phenomenon received the name Open Clusters because of the way that they appear. The stars that they contain are spread out very wide and there is no discernable pattern in the arrangement of the stars.

Additionally, the distance between the stars is very large and there is "less than one star in a cubic parsec of space" (the Milky Way Galaxy 2012). The exciting aspect of these stars is that they contain mainly young stars and hot stars. In this regard many of the stars are very much like our sun. The brightness and the hue of the stars also make them easy to observe. These features mean that the visual presentation of these stars is stunning as well as exciting to observe.

The Globular Cluster was discovered by Messier in 1764. Messier 12 (M12, NGC 6218) as the object is known is marginally larger and more luminous that its close neighbor M10. It is very diffuse, particularly in the center where it is visibly less dense than M10. The spectral type of the cluster was identified as F7 and the color index as 0.0. The "mean magnitude of the 25 brightest stars is 13.97" (Messier 12, 2005) There is however a horizontal band of stars whose magnitude exceeds the mean and they are rated at 13.97.

M12 Dark energy is one of the key concepts employed to explain the expansion of the universe. The major challenge of dark energy is that this concept is difficult to explain. It is essentially a mystery (Dark energy dark matter 2012). The understanding of the expansion of the universe change dramatically based on observations from the Hubble telescope, prior to Hubble it was believed that the universe's expansion could be stopped and thus the possibility of re-collapse eliminated. This was based on the theory that gravity would slow the expansion.

There was no empirical evidence to support this view but the proposition found suitable theoretical support. However Hubble images showed that the universe has been expanding at a faster rate than previously expected. There are multiple explanations of for this phenomenon; dark energy is one of the explanations. Dark energy is considered to be a property of space itself. Empty space contains something so as space expands this dark energy increases. Other theorists suggest that dark energy is a new kind of dynamic energy fluid.

Consequently, while there is a lot of theorizing about dark energy it remains enigmatic. The most likely fate for the Universe is an accelerating Universe. The changing nature of the Universe continues to elicit a lot of theorizing. An accelerating Universe however is highly consistent with the following, firstly Hubble telescope data. The existing data suggest that the galaxies are moving away from each other. This empirical evidence from supernovae is stronger than the theoretical postulations previously advanced.

Additionally, if the universe is actually expanding then there must be an explanation for that expansion. There must be an invisible force that is acting on those galaxies. These two features make the accelerating universe the most probable explanation amongst its competitors (Riess 2012). Major surface features of a) the Earth's Moon The moon's major surface features are craters, rays formed through the crashing of meteorites into the moon's surface. There are also Marias and mountains.

Marias is a dark hole like features of the moon and mountains are high elevations on the surface. b) Mercury Mercury's surface contains a variety of craters, ridges and terrains. The intensity of the cratered area is highly varied as some areas have a large number of craters while other areas are comparatively smooth. The craters are also highly varied from old craters to new craters. Some craters have rays extending from them. c) Europa Unlike the moon and Mercury Europa is very smooth.

The visible markings are "albedo features." Europa is a young body and has few craters it is however tectonically very active. Three ways Uranus and Jupiter differ from Neptune 1. Size-Uranus and Neptune are only about 15 times the size of earth, Jupiter is at least 100 times the size of earth. 2. Uranus and Neptune are cooler 3. The magnetic field is produce by electrically charged water instead of a metallic core like Jupiter.

Open cluster and Global cluster An open cluster is a group of new stars that are basically far from each other. A global cluster is comprised of older stars and they are in closer proximity to each other. The major components of the Milky Way are the (1) the disk (containing the spiral arms)- the disk contains most of the gas and dust that is found in the galaxy. (2) the halo-contains less gas and dust, there are very few stars in the halo.