The first light

These are the first galaxies and the first stars that were formed after the big bang. Because the universe has since been constantly expanding these objects are now the very furthest objects away from us in the universe and are also moving away at the fastest rate. This means that what would have been visible light given off by these object has been red shifted so that the wavelengths are very long when they are received at the Earth, so to detect them we have to look a long way into the infra-red.

How galaxies form

Here the aim is to look into regions in the far distance where new galaxies are just beginning to form. Astronomers want to see how the different types of galaxies we can see (spiral, barred, loose clusters etc.) form and what role the differences in conditions during the early years of their formation play in determining the eventual form of a galaxy.

Star formation

Stars generally form in regions with a high density of dust and gas. One of the main problems in trying to observe star formation is that the dust that surrounds the young stars is opaque in the visible part of the spectrum. However, the infra-red light that is given off by the newly forming star passes through the dust due to its longer wavelengths, therefore by observing in the infrared we can see what is happening inside the clouds of dust and gas around the stars.

 

Artists impression of JWST

Planets around other stars

To trace the origins of the Earth and life in the Universe, scientists need to study planet formation and evolution, including the material around stars where planets form. A key issue is to understand how the building blocks of planets are assembled. Scientists do not know if all planets in a planetary system form in place or travel inwards after forming in the outer reaches of the system. The sensitive instruments on JWST will be able to obtain infra-red images of giant planets and planetary systems and measure their ages and masses.

In addition to studying planets outside our solar system, scientists want to learn more about our own home. Studying the chemical and physical history of the small and large bodies that came together to form the Earth may help us discover how life developed on Earth. JWST will be powerful enough to identify and characterize comets and other icy bodies in the outermost reaches of our solar system, which might contain clues to our origins on Earth.

For more information please contact: RAL Space Enquiries