Physics – 6.2.3 The Universe | e-Consult

Astronomers consider the Milky Way to be one of many galaxies because observations using powerful telescopes reveal countless other collections of stars, gas, dust, and dark matter, all bound together by gravity. These collections are galaxies, and they are distributed throughout the Universe. The Universe is vast, and estimates suggest it contains billions upon billions of galaxies.

The scale of the Universe is difficult to comprehend. Galaxies are grouped into clusters and superclusters, forming a cosmic web. The distances between these structures are immense, spanning billions of light-years. The observable Universe is estimated to be about 93 billion light-years in diameter. Therefore, the Milky Way is just a small part of a much larger structure, and the existence of countless other galaxies is a fundamental aspect of the Universe's structure.