It is hard to comprehend the enormity of our Universe. Our Sun is only one of billions of stars in our galaxy, known as the Milky Way. But beyond the Milky Way, there are billions of other galaxies too. Collectively, all these galaxies, along with the vast amount of space found in between them, make up the Universe.
- How big is our solar system?
- How big is our galaxy and if you reach the edge of our galaxy, what would you see?
- How many galaxies are there?
These are fundamental questions which have long interested humankind. In the more than 70 years since the discovery that the Universe is expanding, we have made some significant steps in understanding how the Universe began and how it must have evolved to be what it is today. We know that galaxies and clusters of galaxies formed from tiny fluctuations in the early Universe. We can measure these fluctuations by mapping the cosmic background radiation and relate them to the structures which we observe today. However, many challenges remain such as:
- Finding the age of the Universe
- Discovering the rate at which the Universe is expanding
Since the discovery of Io, Europa, Callisto and Ganymede (four moons of Jupiter) by Galileo in January 1610, many theories developed regarding distant planets and their movements but it wasn’t until 1922 when a man by the name of Edwin Hubble made the startling discovery that shook the scientific world. Up to this time it was agreed that the entire Universe was made up of the Milky Way but while looking through his 100″ telescope at Mt. Wilson, Hubble observed several spiral nebulae, including the Andromeda Nebula, and came to the conclusion that these nebulae were too distant to be part of the Milky Way, thus coming to the conclusion that these were contained within galaxies of their own. It is now known that our galaxy is only one of billions of galaxies that make up the Universe. Using the links on this site you can navigate through Space and Time and discover planets, stars, nebulae, galaxies and much much more.