A recent study suggests that our home galaxy, the Milky Way, cannot be seen by one-third of humanity. Why? Millions of city lamps brighten our cities every night, but only part of their light is used to actually illuminate streets or sidewalks – the rest is lost and emitted above the horizon, brightening the night sky and contributing to what is known as light pollution. However, as the artificial glow from towns and cities increases every year, the consequences of this urban phenomenon go beyond just preventing us from seeing stars.
