The universe began with a vast explosion that generated space and time, and created all the matter and energy in the universe. Exactly what triggered this sudden expansion remains a mystery.

It's been a long, strange trip for this universe we call home. Follow its development and take a peek at what's ahead with the Mysteries of Deep Space interactive timeline. Simply click on the ...

The expansion of the Universe is not constant ... Our Sun is on one of the spiral arms as shown in the diagram: The Sun's orbital speed is determined almost entirely by the gravitational pull ...