August 5, 2015 2:30 am

James Webb Space Telescope, Look Deeper In The Sky

Looking Deep in the Sky

Famous Hubble’s successor James Webb Space Telescope is soon on the way helping us look deeper in the sky than ever before. James Webb Space Telescope will peer into the past to a time when new stars and developing galaxies were first beginning to form, measuring and capturing images and spectra of galaxies that formed billions of years ago. Seems like James Webb Space Telescope is similar with The Giant Magellan Telescope, the world’s largest telescope which will be able to see big bang.

The James Webb Space Telescope is scheduled to launch in 2018 dubbed to replace Hubble space telescope, like Hubble, it will be able to see distant objects with great detail.

Big year for James Webb space telescope is nearly come. Whereas in the past, the talk has all been about the development and manufacture of individual components, such as Webb’s instruments or its beryllium and gold mirrors – these have all now been produced. The time has come to put everything together in preparation for the big launch into orbit on an Ariane rocket in 2018.


The US aerospace giant Northrop Grumman is the industrial prime contractor and it has just completed the main telescope structure at its facility in Los Angeles. This includes the “backplane” – the part of Webb that will hold the 18 mirror segments in its primary reflecting surface. Shortly, the telescope structure will ship to Nasa’s Goddard centre outside Washington DC for this integration task to begin.

It will be an iconic milestone because, as Eric Smith, the program director and program scientist on this $10bn venture says: it’s the moment when everyone will go: “So, this is JWST!” At last, we will have something that starts to resemble all those artist impressions.

Unlike its predecessor, Hubble, it has some significant differences because of its primary goal, which is to see deeper in the sky than ever before.


It all has to do with the apparent size of Pluto vs a distant galaxy. A galaxy can be billions of times more distant than Pluto, but it’s also much larger, so the apparent size of even the most distant galaxies is larger than that of Pluto. Hubble can see the Andromeda galaxy in awesome detail because it’s apparent size is about 6 times larger than the Moon. It is true that more distant objects tend to have a smaller apparent size than closer ones, but it’s not just resolution that limits depth of view.

To outperform Hubble, the Webb not only has to be larger, it also needs to be more sensitive at infrared wavelengths. The Webb will focus primarily on infrared wavelengths, and it will do so at the cost of seeing less of the visible spectrum. For example, its mirrors are made with a layer of gold, which is very effective at infrared wavelengths but actually absorbs blue wavelengths. So the Webb won’t be able to observe things at the blue end of the visible spectrum. It will, however, be able to see objects at the red end of visible spectrum. The Webb will also be able to observe objects 100 times more faint than the Hubble, and would enable astronomers get new insights for the discovery of cosmos.