This summer, Space.com is celebrating its 25th anniversary! To mark the occasion, here's a look back at the past 25 years of discoveries in astronomy. These are findings that have been absolutely revolutionary for exoplanetary research, cosmology and astrophysics.
Astronomy as a field aims to answer big-yet-fundamental questions about our place in the universe, so it is perhaps most apt to start this list with a bombshell discovery 25 years ago, on April 15, 1999, when astronomers found the first planetary system outside our own.
