Our universe sprang into existence nearly 14 billion years ago—according to astronomy’s current understanding (the date is as yet not absolutely accepted as gospel… science often updates itself). For something like 100 million years after that Big Bang origin, the cosmos dramatically expanded, but would have been essentially invisible at the time, as it consisted almost entirely of hydrogen gas ions. Darkness prevailed and stars had not yet formed. It was a pretty bleak and lonely universe.
Then the first stars began to form some 200 million years after the Big Bang. The cosmos was still rapidly expanding at the time, but now some of that hydrogen began to clump into clouds. Gravity exerted its force and those hydrogen clouds began to compress—increasingly so, until the first stars winked on... or rather ignited, from the intense pressure. That point in time is sometimes called the “cosmic dawn.” Now starlight illuminated the nascent universe. It was no longer totally dark.
Astronomers are very curious about the birth of those first stars. If they could be observed by telescope, our knowledge of the workings of the early universe would be significantly expanded. What were they like? How large and bright were they? What happened next, in the unfolding of the universe? The answers to these questions would help validate our current understanding and models of the cosmos or show us where they may be in error and thus how to improve them.
The most powerful telescope that currently peers not quite that far back in time is the Hubble Space Telescope—the workhorse that has for 30 years shown us some amazing photos and helped confirm our existing cosmic models. Hubble reaches back tantalizingly close to the cosmic dawn, but cannot quite image those first stars.
NASA's James Webb Telescope is the next step in capability beyond Hubble, and astronomers have high hopes that this telescope will reach back to those initial stars and offer some answers to our questions. Astronomers have all their fingers and toes crossed—hoping that the James Webb scope will finally be launched this November. Its launch date has repeatedly been postponed for several years, due to design flaws and thus the program's cost is astronomically over budget. A lot of nail biting will be done by NASA employees between now and November, when it may actually be launched. A lot of money and prestige may soon be lost or, alternatively, gloriously resulting in new discoveries.
[A brief reminder: Due to the continuous expansion of our universe, these long-ago star-birth events occurred at vast distances from Earth... so vast that light (the fastest moving thing in the cosmos) takes billions of years to reach us, to allow us to see these events. So when we first view the light from these initial stars, we will be actually detecting light that shown forth from them, over 13 billion years ago. Those rays may be new to us, but they've been en route across the vastness of space for that long.]
