After all, what is there to discover, if the very first humans lived on the planet anyway?

By Space.com Staff 18 July 2012. Spell. He was working at the Mount Wilson observatory using the brand new 100-inch Hooker telescope when he saw a flash in the "nebula", M31. SamanthaKrywalski. Test.

Astronomy Homework.

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PLAY. What is the important implications of this discovery? Chapter 18-23 homework questions. Gravity. Ancient Greek philosophers proposed that that Milky Way might be a vast collection of stars, to dim to make out individually.

Write. Astronomers now believe that disk galaxies likely formed first, then evolved into elliptical galaxies through galaxy mergers. Learn. The first galaxies were identified in the 17th Century by the French astronomer Charles Messier, although at the time he did not know what they were. Messier, who was a keen observer of comets, spotted a number of other fuzzy objects in the sky which he knew were not comets. Hubble, took long exposures of the spectra of faint galaxies. Seyfert galaxies were first detected in 1908 by Edward A. Fath and Vesto Slipher, who were using the Lick Observatory to look at the spectra of astronomical objects that were thought to be "spiral nebulae".They noticed that NGC 1068 showed six bright emission lines, which was considered unusual as most objects observed showed an absorption spectrum corresponding to stars. Current models also predict that the majority of mass in galaxies is made up of dark matter , a substance which is not directly observable, and … The Milky Way is part of the Local Group, which is dominated by it and the Andromeda Galaxy and is part of the Virgo Supercluster. Asking who discovered the Earth may seem like a silly question—but it isn’t. It was the discovery by Edwin Powell Hubble in October, 1923. The majority of galaxies are gravitationally organized into groups, clusters, and superclusters. Other galaxies had been discovered, but they were thought to be smaller objects within our galaxy. Oldest Spiral Galaxy in Universe Discovered. At the largest scale, these associations are generally arranged into sheets and filaments surrounded by immense voids.

Created by. Who Discovered Earth. Terms in this set (41) Early in the last century, astronomers discovered that most galaxies are moving away from our own, by observing that their light is redshifted. But while this is the case, it took some time before people actually recognized the Earth, the fourth one from the Sun in the Solar System and the only one known to have existing life, is a planet.