James Webb Reveals All!

By Jackson Stephens | Copy Editor

Have you ever wondered what it’s like to travel back in time? Chances are pretty good you have. Every time you go outside on a clear night and look up, you’re instantly transported between four and 16,308 years in the past. Depending on which star you look at, your ticket to the past is punched with a different arrival time.

Distances in the universe are measured in a length called a light year, which is the distance light travels in a year. So when we say a star is five light years away, that means the light from that star took five years to reach our eyes, meaning that light is five years old. Being able to see into the past may seem exciting, but astronomers are over the moon when a faraway galaxy (more than 13 billion light years away) is discovered that offers new insight into what the universe was like in its infancy.

While looking at the night sky is cool, to really see what’s going on in the universe you have to use a telescope. Most ground based telescopes can see a lot farther than the human eye, but even they are limited by Earth’s atmosphere because it absorbs electromagnetic waves on the higher end of the spectrum. Most faraway galaxies are only visible on these frequencies, rendering these kinds of telescopes useless for observing the early years of the universe. This leaves one solution: space telescopes! Telescopes in orbit around Earth aren’t hindered by an obfuscating atmosphere, allowing them to see much further than any telescope on Earth. Up until a year or so ago, this job was mainly filled by the Hubble Space Telescope which was launched in 1990 and has been taking pictures of the cosmos ever since.

Hubble was the main tool used by astronomers to study early galaxies until the James Webb Space Telescope took to the skies in December of 2021. Webb was not fully deployed until August of last year even though it took its first picture a month prior.

Ever since then, Webb has been teaching us more and more about the cosmos on a weekly basis. Olathe North Geoscience teacher Staci Cavanaugh has been in the know about the things Webb has sent back to us since it took that first picture back in July. In fact, one of Cavanaugh’s favorite pictures is one of Webb’s first snapshots. “My favorite [picture] is one of the first five images released: the Carina Nebula. It shows never before seen stars forming within the cosmic cliffs of gas and dust that is the nebula,” Cavanaugh said. One of the great things about Webb is its ability to let us play space tourist and see things we couldn’t see with Hubble. Two things set Webb apart from Hubble: its eyes and its size. Hubble can see things in the UV and visible light part of the electromagnetic spectrum, which have granted us some fantastic views, but Webb sees mainly in the infrared portion of the spectrum, allowing us to see much further than Hubble due to the redshift of the light of receding galaxies. Additionally, Webb’s primary mirror is about six times larger than Hubble’s, which means that it can collate much more light and take a more detailed picture. Cavanaugh thinks these differences set Webb apart from Hubble in a completely unprecedented way. “It is impossible to truly convey the significance of Webb’s data thus far. With our ‘new set of eyes’ we can see nebulae in greater detail than ever before. Astronomers will be able to see some of the first galaxies ever formed after the Big Bang,” Cavanaugh explained. Being able to see these galaxies that were around when the universe was in its infancy is huge scientific news because it allows us to gain a greater understanding of what the uni- verse was like back then and how things got to where they are now. It’s about as close as we’ll get to seeing the Big Bang. Will we see the Big Bang? According to Cavanaugh, chances are pretty slim. “I truly don’t know if Webb would be capable of seeing the Big Bang. Ideally, the heat from that event would be too small for Webb’s mirrors to detect,” Cavanaugh said. Since Webb can see mostly in the infrared spectrum, a lot of the detail it captures depends on the heat emitted from faraway objects. The heat emitted from those early galaxies was already so “tiny” that the dot that showed up had to be magnified copiously to determine what it was. This means that looking even further back to the Big Bang is probably impossible. Despite this disappointing prognosis, Cavanaugh is excited about what the future holds for Webb. “Webb proved that we could fold up a large telescope and deploy it in space, which means more big space telescopes in the future! It also has a tennis court sized sunshield to block out heat instead of using coolant onboard, which will allow for longer lifetimes of future missions,” Cavanaugh said. Cavanaugh was also very excited about how future generations will interact with the data Webb collects, noting that “[t]his technology will allow us to see life signatures on exoplanets (planets not in our solar system) and detect the most detailed data on star formation. Textbooks will need to be rewritten from what Webb will continue to discover!”