| Answer | Crossword Clue |
|---|---|
| EON | Division of about one billion years |
| EON | The Hadean was the first one, ending about 4 billion years ago |
| universes | All existing matter and space considered as a whole; the cosmos. The universe is believed to be at least 10 billion light years in diameter and contains a vast number of galaxies; it has been expanding since its creation in the Big Bang about 13 billion years ago |
| EON | About a billion years |
| AEON | One spelling of a billion years |
| aeons | unit of geologic time equal to one billion years |
| eons | unit of geologic time equal to one billion years |
