Earth from space, Earth in space

Earth is our home planet. But we know very little about it. And less even about the true scale of things on Earth and around Earth.

This talk is organized in four chapters. On the first one a real notion of our planet's scale is provided, starting by marking some cities in a world map and the distances beetwen them and then moving on to compare the size of the continents and oceans, the largest countries and the smallest ones.

The second chapter is about the Solar System and its scale. Starting with the Earth-Moon system we arrive at the size of the planets and the Sun and the distances beetwen them using true scale diagrams.

The third chapter is about the Milky Way, our galaxy. What's its size and how insignificant is the Solar System on the galactic scale. And also how small is our sun when compared to so many other stars.

Finally, the fourth chapter is about the Universe. Its scale, the galaxies that are part of it, the immense emptyness of space.

In this talk it gets clear why we usually say that really, really large numbers are... astronomical!