Where Are the First Stars and Galaxies?

Download This Video (.mov 1280x720 321.26MB)

We are privileged to live in a time when the story of Genesis, the beginning of all that is, can be critically explored by direct observations.

Because of the finite time it takes light to travel from the distant reaches of creation, we can take images of the universe when it was younger by looking deep in space-time through ever more power powerful telescopes.

Modern cosmology provides us with a framework of understanding from the earliest history of the cosmos through to the present day. Using our space-based and large ground-based telescopes, we have observations and data that provide detailed maps from a time when the universe was just 400 thousand years old and images of the first galaxies when the universe was around a billion years old.

Unfortunately, we have almost no data, no images, of the time in between. No observations of the period between the cooling big bang and the first galaxies around a billion years later.

This is akin to having a photo album of someone that begins with the first ultrasound and then no photos until that person was as a teenager or an adult.

We need more observations between the infant, primordial universe and the cosmos as a teenager.

The one fuzzy image of this time that does exist comes to us, accidentally, from the Spitzer Space telescope.

Here is an image taken from the Spitzer Infrared Camera pointed in the constellation Draco and covers an area of about 50 by 100 million light years. This image was taken at 3.6 microns, a wavelenght invisible to the human eye.

After painstakingly masking instrument artifacts and subtracting all known sources of light from foreground stars, galaxies and nebulae, astronomers discovered a faint glow that could not be attributed to any of the other objects in the image.

This glow is believed to come from the photons of the very first stars in the universe. They appear as blobs because they are not resolved, too faint and distant for the cameras on Spitzer.

Here is the collective light from millions of the first stars ever to shine and while they have long since died away, their light is still travelling, outrunning the expansion of the universe to our detectors.

These stars were likely over one hundred times more massive than our Sun and extremely hot, bright and very short lived - each one burning only a few million years.

These early stars would have been very bright in the ultraviolet, but by the time they reach us over the eons, their light has been redshifted into the infrared.

And it is in this part of the spectrum that we must take our pictures if we are to see the first stars, to directly observe the early embers of creation.

The Spitzer Space Telescope has long since run out of its Helium coolant necessary to take these images. To take more, we must employ a new telescope, one sensitive to the infrared with an aperature large enough to resolve these distant objects.

The James Webb Space Telescope is designed precisely to do this. Using 18 onboard detectors, most sensitive to the IR, over a half a TB of images per detector per week will be transmitted to earth, with many surveys planned for the first stars and galaxies.

Much has yet to be learned about the childhood of the cosmos, and the James Webb Space Telescope is the next spacecraft to help fill the missing pages in our cosmic photo album.