The nearest star to Earth is Proxima Centauri, located approximately 4.3 light-years away. The discussion also touches on the distance across a galaxy and the size of the observable universe, which is often cited as around 46 billion light-years based on current cosmological models. There is some confusion regarding the edge of the observable universe, with one source incorrectly stating it as 78 billion light-years. For accurate information, references such as Wikipedia and Ned Wright's cosmology FAQ are recommended. Understanding these distances is crucial for grasping the scale of the universe.