Questions Show: Decelerating Black Holes, Earth-Sun Tidal Lock, and the Crushing Gravity of Dark Matter

This week we wonder if you can made a black hole by accelerating a mass, but then can you un-make it again? Will the Earth ever be tidally locked to the Sun? And can dark matter crush an unsuspecting space ship?
If you’ve got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and we’ll try to tackle it for a future show. Please include your location and a way to pronounce your name.

Ep. 682: Ultra-Diffuse Galaxies and Dark Matter

Ep. 682: Ultra-Diffuse Galaxies and Dark Matter

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?

Ep. 550: Missing Epochs – Observing the Cosmic Dark Ages

Ep. 550: Missing Epochs – Observing the Cosmic Dark Ages

Powerful observatories like Hubble and the Very Large Telescope have pushed our vision billions of light-years into the Universe, allowing us to see further and further back in time. But there are regions which we still haven’t seen: the Cosmic Dark Ages. What’s it going to take to observe some of these earliest moments in the Universe?

Ep. 503: Gravity Mapping

The Earth looks like a perfect sphere, but down here on the surface we see that there are mountains, rivers, oceans, glaciers, all kinds of features with different densities and shapes. Scientists can map this produce a highly detailed gravity map of our planet. And it turns out, this is very useful for other worlds too.

Ep 488: Dark Energy: 2018 Edition

The updates continue. Last week we talked about dark matter, and this week we continue with its partner dark energy. Of course, they’re not really partners, unless you consider mysteriousness to be an attribute. Dark energy, that force that’s accelerating the expansion of the Universe. What have we learned?

Ep 487: Dark Matter: 2018 Edition

Last week, we gave you an update in particle physics. This week it’s time to see what’s new in the world of dark matter. Spoiler alert, we still have no idea what it is, but maybe a few more ideas for what it isn’t.

Questions Show – light speed, Andromeda galaxy, dark matter and black holes

Another week, another roundup of your questions. This week listeners asked: will reaching light speed destroy the Universe? When is Andromeda going to look really, really cool with the unaided eye? Why didn’t dark matter all turn into black holes? And there’s even more. If you’ve got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and we’ll try to tackle it for a future show.

Ep. 11: A Universe of Dark Energy

The discovery of dark energy was one of the biggest surprises in astronomy. Instead of a nice, predictable expanding Universe, acted on only by gravity, astronomers turned up a mysterious repulsive force accelerating the expansion of the Universe. Fraser and Pamela explain
the evidence for a dark energy, and a few possible theories for what could be providing this repulsive force.

Ep. 4: The Search for Dark Matter

Dark matter . . . What is it? Nobody knows for sure, but it’s definitely there. Or maybe it’s not there, and we just need some redefinition of gravity at vast scales. Join Fraser and Pamela as we discuss the discovery, detection, and possible explanations of dark matter.

Ep. 683: Cosmic Dawn

Ep. 683: Cosmic Dawn

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.

Ep. 667: JWST First Science Results

Ep. 667: JWST First Science Results

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?

Ep. 665: The Age of Reionization

Ep. 665: The Age of Reionization

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 Reionization.

Ep. 640: Survey Science: Newest Projects and Results

Ep. 640: Survey Science: Newest Projects and Results

There are general-purpose telescopes and missions that astronomers can use to study specific objects. And there are survey missions that look at the entire sky, which astronomers can use to answer questions about the Universe. We’ve talked about surveys in the past, but the landscape is changing fast so it’s time for an update.

Ep. 638: Simulating Space Missions

Ep. 638: Simulating Space Missions

Although humans have never actually been to Mars, explorers have simulated many aspects of Mars missions here on Earth. There are missions under the ocean, on the tops of volcanoes, in the harsh Canadian north, and even in bed that simulate the limitations of spaceflight, and teach us many of the lessons to prepare us for the real thing.

Ep. 634: Milky Way’s Mergers & Acquisitions

Ep. 634: Milky Way’s Mergers & Acquisitions

The Milky Way is a vast grand spiral today, but how did it get this way? Astronomers are starting to unravel the history of our galaxy, revealing the ancient collisions with dwarf galaxies, and how they came together to build the Milky Way.

Ep. 631: All the Uses of Pulsars (Including Murder)

Ep. 631: All the Uses of Pulsars (Including Murder)

Pulsars are the rapidly spinning degenerate husks of dead stars, turning hundreds of times a second. But they’re also handy clocks, spinning with such certainty and accuracy that astronomers can use them for all kinds of stuff. We might even use them to navigate the cosmos.

Ep. 628: The Sun Revisited

Ep. 628: The Sun Revisited

Once again, it’s time to take a look at the Sun. You know, ongoing thermonuclear explosion of fusing hydrogen that’s right over there. Fortunately, there’s a fleet of spacecraft and ground observatories ready to give our best ever view of the Sun.

Ep. 625: End of the Year Review

Ep. 625: End of the Year Review

We’ve reached the end of 2021, and this is the last episode of the year. Let’s look back at the big space events of the last year and talk about what we’re looking forward to in 2022.

Ep. 624: Small Rocky Bodies (Including Phobos and Deimos)

Ep. 624: Small Rocky Bodies (Including Phobos and Deimos)

We’ve talked about the icy objects of the Solar System, today let’s talk about space rocks. There’s a surprising variety of rocky material in the Solar System, and each object has a story to tell about the history and formation of the planets, moons and other rocky bodies.

Ep. 615: Planet 9

Ep. 615: Planet 9

After Pluto lost its planethood, we were down to 8 planets. But there’s growing evidence of another world (or worlds) out beyond the orbit of Pluto. Is Planet 9 out there and how will we find it? Could there even be a Planet 10?

Ep. 607: InSight and Marsquakes

Ep. 607: InSight and Marsquakes

Mars is cold and dead today, but the massive volcanoes tell us what the planet used to be like, millions and even billions of years ago. But how volcanically active is the planet today? That’s what NASA’s Mars InSight lander is there to figure out.

Ep. 606: Time Dilation – Skipping Through Time

Ep. 606: Time Dilation – Skipping Through Time

Have you ever wanted to be a time traveler? Good news! You’re time traveling right now. Into the future at one second per second. Too long? Don’t want to wait? Good news, Einstein’s got you covered. Today, let’s talk about the weird world of time dilation.

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