The James Webb Telescope

Some of you may remember I have a deep interest in astronomy and although it has been nearly a year since I have peered through my telescope, I still reach for news related to astronomy, and it is a huge story that is beginning to be explained starting today.

The James Webb Space Telescope is a huge, extremely complicated piece of equipment and its deployment, a million miles from Earth exceeds its complexity by an order of magnitude. The Webb's wiki is here:James Webb Space Telescope

This is an image of what the Webb Telescope will look like in space:

Some of you may remember the first image of the Hubble Space Telescope being horribly out of focus, the effort it took to correct the image as shown below:

Consider the engineering that went into constructing the Hubble and somehow realize that nearly 10 times the effort went into the Webb versus the Hubble. The Hubble's main mirror was 9' in diameter whereas Webb's mirror is comprised of 18 hexagonal segments when fully extended will create a mirror 21' in diameter. The Webb mirror is also coated with gold as its primary purpose is to look for infra-red objects in space and gold reflects infra-red photons better than a mirror as the Hubble has.

So, today, the Webb's first image was announced to the world, and here it is:


This is a spectacular image of a piece of space that if you held up a finger, your fingernail would cover the area. The image shows an area of space where an item is so massive it is literally bending space and that is why some of the galaxies are distorted, looking a bit like apple slices.

I don't like to use the word/term 'pride' often, but the collaboration between NASA and ESA is incredible and the result of that collaboration is the James Webb Space Telescope and I admit to having a bit of pride in knowing that my country, the U.S. participated in its success.

Hi Michaela,

It is quite amazing. The clarity of those galaxys. There are around an average of a trillion stars in a galaxy... and more galaxys than humans that have ever walked the earth. The numbers are breathtaking.

I look forward to seeing more pictures from this incredible piece of equipment.

Celia xx

In a largely depressing world, this is a great achievement for our species.

Saw that image the other day. It is awesome.

NASA has posted more images at Webb First Images

There are two main reasons for the clarity of the images: 1) the Webb is designed for infra-red observing which allows for stars that are embedded in the galactic/intergalactic dust to be clearly seen as the star's heat shows through the clouds of dust in and between galaxies and 2) the larger the diameter of the telescope determines the resolution inherent in the system,

As I mentioned above, the Hubble has a 9' mirror whereas the Webb has a 21' mirror. There is something called the Dawes limit which is a theoretical measurement of the resolving power of a telescope. In the case of the Hubble, the resolving power is 0.04 arcseconds. In the case of the Webb, the resolving power is 0.018 arcseconds (the smaller the number the better resolution).

The resolving power of my 'little' telescope is 0.39 arcseconds. The biggest difference between mine, of any land-based telescope (regardless of size), is the atmosphere it has to look through to see anything in space. Both the Hubble and the Webb are above Earth's atmosphere and in the case of the Webb over a million miles from Earth.