| Black Holes |
Regions of spacetime where gravity is so intense not even light can escape. |
Estimated 100 million in our galaxy; closest known is ~5,000 light-years away. |
| Supernovas |
Explosive deaths of massive stars, releasing enormous energy. |
Can sterilize areas up to 50 light-years wide. |
| Gamma-Ray Bursts |
Extremely powerful beams of radiation often from collapsing stars. |
Can wipe out life instantly; often undetectable until too late. |
| Cosmic Voids |
Enormous empty regions with almost no galaxies. |
Bootes Void spans over 330 million light-years. |
| Size of the Universe |
The observable universe extends in every direction farther than we can comprehend. |
Approx. 93 billion light-years in diameter; age 13.8 billion years. |
