Cosmic Perspectives from Amid the Stars:
Astronomy Blog

The solar eclipse is the well-known event when the Moon passes between the Earth and Sun, blocking the Sun from view. Less known is the lunar eclipse, where the Earth passes between the Sun and Moon, blocking the light of the Sun that usually reflects off the Moon. The morning of March 3, 2026, at around 3:00 am PST, will provide this special show of celestial alignment.

You might have heard before that the nearest star is 4.24 light-years from Earth. Or that the closest galaxy is 2.5 million light-years from the Milky Way. Or even that the most distant observed objects are 33.8 billion light-years away. But how do we measure these distances in space? After all, there’s no such thing as a cosmic ruler. That’s where the cosmic distance ladder comes in.