One of JWST’s top jobs is to peer deeper into the Universe than ever before, watching as the first galaxies came together. Surprisingly, astronomers found galaxies that seemed much more mature than expected, much earlier than it was believed possible. What’s going on and what does it mean for cosmology?
After the cosmic microwave background radiation was released, the Universe returned to darkness, cloaked in this clouds of primordial hydrogen and helium. Gravity pulled these vast clouds into the first stars, and then the first galaxies. This is Cosmic Dawn, and JWST will help us probe this mysterious time.
Astronomers first noticed the strange behaviors of rotating galaxies almost 100 years ago, suggesting there’s an invisible dark matter hold them together with gravity. Or maybe we just don’t understand how gravity works at the largest scales. Observations are much better now, and astronomers have found examples of galaxies that almost entirely made of dark matter. Does this tell us anything?
In 2017, astronomers detected the gravitational waves and electromagnetic radiation from colliding neutron stars. This had been long theorized as one of the causes of a certain type of gamma-ray burst. By studying the event and its afterglow, astronomers have learned a tremendous amount about the formation of the heaviest elements in the Universe.
Recent Episodes
https://www.youtube.com/watch?v=5_1L_P24gT4 It’s been over 20 years since astronomers first discovered that the expansion of the Universe is accelerating thanks to dark energy. And in these decades, astronomers still don’t have much evidence for what could be causing...
https://www.youtube.com/watch?v=2n6HKpWaEEE Astronomers have made extremely accurate measurements of the expansion rate of the Universe and come up with different results. And the error bars for the observations don’t overlap, so there’s something strange going on....
https://www.youtube.com/watch?v=BbMBAivcnes Astronomers came together in January to present their newest research, and not surprisingly, the Winter AAS meeting was heavy on news from JWST. What were some of the new results that were announced? Download MP3 | Show...
https://www.youtube.com/watch?v=8QwZoy58ZR8 Well, we did it. We made it to episode 666, an auspicious number to be sure. What can we do to celebrate this accomplishment? An episode all about things in the Universe that have been named after mythological people and...
https://youtu.be/ceUI7wR76gE The Cosmic Microwave Background Radiation tells us so much about the Universe. After that era, the Universe went dark. Then, as gas pulled together into the first stars and eventually galaxies, light returned, beginning the Age of...
https://youtu.be/zK4Palgj6zI The Sun is a third-generation star, polluted with the metals from long-dead stars. Astronomers have also discovered second-generation stars, with very low metallicity. But theories suggest there must be a first generation, with stars made...
https://youtu.be/ImwJ1FblRhU We generally save our stargazing suggestions for the summer, when it’s warmer in the northern hemisphere. But you’re tough, you can handle a little cold. And it’s worth it because there are some wonderful things you can see in the night...
https://youtu.be/shKSE47JmjY Last week we talked about the missions we’re saying goodbye to. This week, we’re going to talk about some upcoming missions to say hello to. Some are brand new ideas, others are, uh, recycled. Download MP3 | Show Notes | Transcript Show...
https://youtu.be/TicUn1-ak3Y It’s always sad to say goodbye, but when we send our robotic emissaries out into the cosmos, it’s just a matter of time before they shut down. Today we’re going to say goodbye to a few missions which have reached the end of their lives....
https://youtu.be/_jE0X9eb-54 Moons orbit planets, planets orbit stars, stars orbit within galaxies. It’s orbits all the way down. But occasionally objects can receive a powerful kick that sends them off on a journey, never to return. PART II PART III Download MP3 |...
https://youtu.be/PbOnrSZbRjA Light pollution is a big problem, and it’s only getting worse -- not just near cities but everywhere thanks to increased satellite constellations. How bad is the problem, and how can we fix it? Download MP3 | Show Notes | Transcript Show...
https://youtu.be/sdQF-jHLVpk We’re recording this episode on Halloween, so how could we resist but take advantage of this opportunity. Space is already terrifying enough, you know, with the vast endless emptiness, incomprehensible mysteries, and uncaring coldness. But...
https://youtu.be/caF8-BCJGPc Space is a big place, with a lot of galaxies, stars, planets and moons, and that means a lot of names. How do astronomers name stuff, like comets, asteroids, exoplanets, craters? Download MP3 | Show Notes | Transcript Show Notes...
https://youtu.be/QNZmj1XfpmA This week we saw the incredible image of DART smashing into asteroid Dimorphos. Beyond avenging the dinosaurs, what can we learn scientifically from this and other asteroid/comet impact missions? Download MP3 | Show Notes | Transcript Show...
https://youtu.be/f1ysu0nH1eY It’s been about 65 years since the Soviets launched the first orbital satellite into low Earth orbit: Sputnik 1. Now there are thousands of satellites in orbit, with tens of thousands on the way. Let’s look at the impact that Sputnik had...
https://youtu.be/zk8JkaOdnUY To battle climate change, we’ll need to rapidly move to carbon-free sources of energy. But this technology isn’t a free lunch. They require metals, generate waste and deplete the environment. What’s the best way to balance this shift?...
https://youtu.be/RmqwHtTzpzM Climate change is on our minds these days, with increasing wildfires, droughts and floods. What are the variables that play into a planet’s changing climate, and what can this teach us about the search for habitable planets across the...
https://youtu.be/juXi4CVJBC8 Last week we talked about how single-use rocketry has changed over time, and the role it still plays in launching payloads into orbit and beyond. Today, we’ll address the stainless steel elephant in the room and talk about the shift to...
https://youtu.be/aXu8Hmqkz2M On the day that we’re recording this, NASA’s Space Launch System is about to blast off. But everyone is expecting it’ll be delayed to October. When it does launch, it’ll be the most powerful rocket on Earth. Well, until Starship blasts...
https://youtu.be/8g8eZtvagGY?t=211 Well, this is it, we’re finally going to talk about the James Webb Space Telescope. After decades of development, delays and budget creep, the powerful infrared observatory is at its final home at the L2 Lagrange Point. Yesterday we...
