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What are the differences between the Webb and Hubble space telescopes?


Uploaded on December 20, 2021


What are the differences between the Webb and Hubble space telescopes?

2021-12-20 – The Webb and Hubble space telescopes are different, but they complement each other in several ways. The James Webb Space Telescope will be Hubble's successor, but not its replacement. The two missions have a planned overlap and will work together on new discoveries. Webb will build on Hubble's impressive legacy by helping humanity peer even deeper into the universe. (Credits: Canadian Space Agency, NASA)


Sara Gallagher: We asked you what you wanted to know about the science of Webb.

David Saint-Jacques: And we’re here to answer your questions.

Hi, I’m David Saint-Jacques.

Sara Gallagher: And I’m Sarah Gallagher.

Sara Gallagher and David Saint-Jacques: And you are an astrophysicist!

David Saint-Jacques: How are the mission and capabilities of Webb different from those of Hubble?

Sara Gallagher: There are many differences between Hubble and Webb.

Webb is larger than Hubble. Its primary mirror is 6.5 metres wide, and Hubble’s is 2.4 metres wide.

That makes a big difference, because a mirror is basically a light bucket, and the more light you capture, the more sensitive you are to things that are really, really faint and far away. That means that Webb can see farther into the cosmos.

Webb’s location is also much farther away in space, 1.5 million kilometres from Earth orbiting the Sun at a point known as Lagrange 2. But Hubble is in low Earth orbit, which is only about 550 kilometres away.

The reason it’s great that Webb is so far away is that it gives us an unobstructed view of the sky because you don’t have to worry about the Earth getting in the way.

David Saint-Jacques: Wow!

Sara Gallagher: Webb and Hubble are also looking into different types of light. So Webb is designed to focus on the near- and mid-infrared parts of the spectrum. And Hubble uses mostly visible and ultraviolet light.

David Saint-Jacques: More questions will arise as Webb opens a new chapter in our understanding of the universe.

Sara Gallagher: Join astronomers from across Canada and around the world on a thrilling journey of discovery.


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