Cosmic Perspectives from Amid the Stars:
Astronomy Blog

Social media is buzzing with news of a so-called “planet parade” on Saturday, February 28. But before you get your hopes up, let’s separate the astronomical reality from the viral hype.

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.