What’s the difference between the Hubble Space Telescope and James Webb ?

 The James Webb telescope was launched on December 24th, 2021, to succeed the Hubble Space Telescope, which is incredibly important due to its many discoveries in astronomy, like the age of the universe and that there are black holes in the centre of galaxies. But what are the big differences between these two space telescopes?

Firstly, the two telescopes see in different ways. Hubble has a mirror that’s “2.4m wide”, while James Webb has a segmented “6.5m wide mirror” (NASA/ESA/M.Livio & Hubble 20th Anniversary Team (STScI)). This means it can get more light and therefore also see more things. The type of light they see is also different. Hubble used primarily ultraviolet and visible light and Webb uses mostly infrared rays. This was changed from Hubble because visible light can be blocked by dust in space while infrared light doesn’t have such obstacles making James Webb more efficient at collecting data. However, infrared telescopes need to stay cool to work appropriately since heat can mess up the data and images, which is why James Webb has its huge sun shield, which is as big as a tennis court!

Next, Hubble Space Telescope and James Webb Space Telescope differ in where they’ll orbit and as a result, their operation and maintenance. Hubble operates in Earth’s orbit, 570 km from it, meaning that we could maintain it with space shuttle missions. On the other hand, James Webb operates 1.5 million kilometres from Earth, in a special astronomical place called Lagrange point, specifically Lagrange Point 2. A Lagrange point is a point in space where an object stays around the same position and doesn’t move that much. This is because the “gravitational pull of 2 large masses is equal to the force for an object like a telescope to move with them” (NASA/WMAP Science Team). These points are useful because they give clear and consistent views of space while still being able to receive energy and communications from the Earth and Sun.

In conclusion, these were some of the major differences between these two space observatories. I think the James Webb telescope is going to be monumental for space exploration and I can’t wait to see what it discovers. I also hope that it lives up to Hubble’s legacy and works properly because no one wants a $10 billion issue that can’t be fixed due to its position, but hopefully, one day, the launch day of the James Webb Space Telescope will be remembered as a crucial point in human history. 

Sources: 

https://www.jwst.nasa.gov/content/about/comparisonWebbVsHubble.html

https://solarsystem.nasa.gov/resources/754/what-is-a-lagrange-point/