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...

The galaxies are separated into elliptical and spiral galaxies, elliptical galaxies form the handle of the tuning fork and spirals one arm. The other arm is formed by irregular galaxies. Elliptical are round and flat while spiral galaxies have a bright line running through them, and are spiral shaped. Irregular galaxies have none of these attributes.
Distance and size of galaxies are measured using the light that the galaxy emits. Specific stars are identified within the galaxy whose light output can be measured. Based on these measurements the distance is determined. If this is not possible then they may turn to Supernovae to measure distance and size of the galaxy.

References

Components of the Galaxy (2012). Retrieved from http://csep10.phys.utk.edu/astr162/lect/milkyway/components.html

Dark Energy Dark Matter (2012) National Aeronautics and Space Adminsitration. Retrieved from http://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/

Messier 12 (2012). Retrieved from http://messier.obspm.fr/Mdes/dm012.html

The Hubble tuning fork (2012).

http://skyserver.sdss.org/dr1/en/proj/advanced/galaxies/tuningfork.asp

Riess, a.G.(2005) My Path to the Accelerating Universe. Retrieved from http://www.stsci.edu/~ariess/documents/Shaw%20Prize%20Lecture_web.pdf