The Milky Way is visible at night because we are located within the Milky Way galaxy itself. When we look up at the night sky, we see the combined light of billions of stars that make up our galaxy.
The visibility of other galaxies, on the other hand, depends on various factors such as their distance from us, their brightness, and the level of light pollution in our surroundings. Most galaxies are located at vast distances from us, often millions or billions of light-years away. These distances make them appear much smaller and dimmer in the night sky compared to the stars within our own galaxy.
Additionally, the individual stars within other galaxies are generally much farther apart from each other compared to stars within the Milky Way. This contributes to the overall faintness of other galaxies when observed from Earth.
Furthermore, light pollution from human activities, such as streetlights and urban developments, can significantly hinder our ability to see faint objects in the night sky, including distant galaxies. In areas with high levels of light pollution, the visibility of even the Milky Way itself may be diminished.
To observe other galaxies, astronomers typically use telescopes, which gather and amplify light, enabling them to see objects that are too faint to be detected with the naked eye. These observations are often conducted in dark and remote locations or in space-based observatories where light pollution is minimal, allowing astronomers to study and appreciate the diverse range of galaxies that populate our universe.