Why is the European Space Agency building the largest space telescope ever? Science journalist Martin Peters explains | science and planet

The European Space Agency (ESA) has presented its plans for the James Webb Space Telescope. This has to be the biggest and most powerful of all. 1200 scientists from 14 countries are involved in the construction, the US NASA and the Canadian Space Agency are also involved. So their ambition is big: to replace the Hubble Space Telescope this year. But why is it this big? And why should the Hubble Space Telescope be replaced? And above all: what exactly does the ESA want to do with it? Science journalist Martin Peters explains it in the video above.