The Milky Way
In summer, in a clear place with dark night skies, an irregular glowing band arcs high overhead. The ancients likened
How fast is Earth moving through space?
To begin with, Earth is rotating on its axis at the familiar rate of one revolution per day. For those
How many stars are in the Milky Way?
Most estimates place the number of stars in our galaxy at between 100 billion and 500 billion.
How big is our galaxy?
The Milky Way’s disk spans at least 100,000 light-years and probably contains several hundred billion stars, which makes our home
How many galaxies are there in the universe?
Quite a few. Most estimates place the number of galaxies at around 100 billion. Most of those galaxies are little