People, stars and galaxies
There are more a hundred billion or so stars in our Galaxy, which we call the Milky Way.
Look at this letter: x
Now try to picture a hundred billion letters. You can’t. You’d find that many letters in a million or so books. They would need a bookshelf more than 20 kilometres long.
That’s in just one galaxy. The Hubble Space Telescope is capable of detecting almost a hundred billion galaxies and there are very likely to be many more that are too faint to see but are within the ‘observable Universe’.
- There are about 6 billion people on Earth and a hundred billion stars in the Milky Way. How many stars are there for each person?
- Roughly how many galaxies are there in the Universe, for each person?
- Roughly how many stars are there in the Universe, for each person?
- Estimate the length of bookshelf that would be needed to hold books with the same number of letters as there are stars in the observable Universe.