We are actually able to see many other galaxies from Earth. In fact, there are billions of galaxies in the universe, each containing billions or even trillions of stars. However, the visibility of other galaxies can be influenced by several factors:
Distance: The vast majority of galaxies are located at enormous distances from our own Milky Way galaxy. The light from these distant galaxies takes a significant amount of time to reach us. As a result, we observe them as they appeared in the past. The most distant galaxies we can currently observe are from the early universe, as their light has taken billions of years to reach us.
Brightness: Galaxies vary in size, composition, and the number of stars they contain. Some galaxies, particularly the larger ones, can be quite bright and easily visible, even from relatively large distances. However, many galaxies are dimmer and more challenging to observe, especially if they are located far away or obscured by interstellar dust or other objects in their vicinity.
Light Pollution and Atmospheric Effects: Light pollution from human activities, such as streetlights and cities, can obscure the faint light from distant galaxies. Additionally, Earth's atmosphere can cause blurring and distortion of celestial objects, making it more difficult to observe faint or distant galaxies.
Observational Limitations: Our ability to observe distant galaxies is also limited by the capabilities of our telescopes and instruments. Advancements in technology, such as the development of space telescopes like the Hubble Space Telescope, have significantly improved our ability to observe and study galaxies in great detail.
Despite these challenges, astronomers have been able to identify and study a vast number of galaxies beyond our Milky Way using various observational techniques. These observations have greatly contributed to our understanding of the universe's large-scale structure, cosmic evolution, and the diversity of galaxies.