The Milky Way[a] is the galaxy that contains our Solar System, with the name describing the galaxy’s appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term Milky Way is a translation of the Latin via lactea, from the Greek γαλαξίας κύκλος (galaxías kýklos, “milky circle”). From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies.
Makemake is about a fifth as bright as Pluto. However, despite its comparative brightness, it was not discovered until well after a number of much fainter KBOs had been detected. Most of the scientific hunts for minor planets are conducted relatively close to the region of the sky that the Sun, Earth's Moon, and planets appear to lie in (the ecliptic). This is because there is a much greater likelihood of discovering objects there. Makemake is thought to have evaded detection during earlier searches because of its relatively high orbital inclination, as well as the fact that it was at its greatest distance from the ecliptic at the time of its discovery--in the northern constellation of Coma Berenices. The "Dagwood Sandwich" Moon. Earlier models of Ganymede's oceans were based on the assumption that the existence of salt didn't change the nature of liquid very much with pressure. However, Dr. Vance and his colleagues found, through laboratory experiments, that salt does increase the density of liquids under the extreme conditions hidden deep within Ganymede and similar icy moons with subsurface bodies of water. Imagine adding table salt to a glass of water. Instead of increasing in volume, the liquid will actually shrink and become denser. The reason for this is that salt ions lure water molecules. In addition, the newly collected data derived from the GRAIL mission helps astronomers redefine the late heavy bombardment--a proposed episode that occurred about 4 billion years ago, during which a heavy shower of projectiles pelted the bodies of the inner Solar System, including Earth and its beloved Moon, creating heavy lunar cratering in the process. The concept of the late heavy bombardment is primarily based on the ages of massive near-side craters that are either within, or adjacent to, dark, lava-flooded basins (lunar maria), that are named Oceanus Procellarum and Mare Imbrium. However, the composition of the material existing on and below the surface of the lunar near-side indicates that the temperatures beneath this area are not representative of Earth's Moon as a whole at the time of the late heavy bombardment. The difference in the temperature profiles may have caused scientists to overestimate the amount of crater-excavating projectiles that characterized the late heavy bombardment. New studies by GRAIL scientists indicate that the size distribution of impact craters on the lunar far-side is a more accurate reflection of the crater-forming history of the inner Solar System than those pock-marking the near-side.