When Edwin Hubble observed that distant galaxies are speeding away from us in all directions, he discovered the reality that we live in an expanding Universe. Hubble worked to calculate exactly how fast this expansion is happening, creating the Hubble constant – which astronomers continue to refine and reference in their research.
AstronomyCast
Ep. 278: Animals in Space
We always think about humans in space, but the cold hard reality is that animals have always been first in space. First to fly, first to orbit, and sadly, first to die. Let’s learn about how our animal companions have been our trusty partners in space exploration, and let’s recognize their noble sacrifices over decades of experiments.
Ep. 277: Orbit
When an object is orbiting the Earth, it’s really falling. The trick, described in the Hitchhiker’s Guide to the Galaxy, is how to throw yourself at the ground and miss. There are several different kinds of orbits, and they are good for different reasons. From suborbital jumps to geostationary orbit, time to learn everything there is to know about going around and around and around.
Ep. 276: XMM-Newton
The Earth’s atmosphere keeps us alive and blocks x-ray radiation from reaching the surface. In order to understand the universe at the higher energy levels you need to launch a space telescope like the European Space Agency’s XMM-Newton Telescope. Let’s learn about the telescope named for the famous scientist.
Ep. 275: Isaac Newton
Isaac Newton has been called “the greatest and most influential scientist who ever lived.” That sounds about right. He unlocked our modern understanding of gravity and laws of motion, dabbled in optics, philosophy… even alchemy. He was also known to have a bit of a difficult personality. Let’s find out everything we can about Isaac Newton.
Ep. 274: Vesta
There’s some topics on Astronomy Cast that we wait until we are good and ready, until the science is all in. The Dawn mission has completed it’s mapping operations at asteroid Vesta and it’s now moving on to Ceres. This gives us a great opportunity to take a detailed look at this amazing asteroid, report on the science findings, and give you a preview of what’s coming next.
Ep. 273: Solutions to the Fermi Paradox
In Episode 24 we presented the concept of the Fermi Paradox. In short: Where are all the aliens? Today we’re going to examine the theoretical solutions to this problem. Maybe they’re out there, but just don’t want to talk to us. Maybe it’s too hard to communicate? Maybe there are no other civilizations. Maybe civilizations wipe themselves out when they reach a certain point. So many solutions, none of them satisfactory.
Ep. 272: Abiogenesis
The Theory of Evolution provides a rich explanation for why we see the diversity of life here on Earth. There are so many lines of evidence, from genetic drift to the fossil record. But how did life start? How did things go from a collection of raw materials to the building blocks of life, giving evolution and natural selection a way to take over? That first step, from non-life to life is called “abiogenesis”, and it’s one of the most important questions science can answer.
Ep. 271: Who Does What in Space and Astronomy
In past, if you looked up into the sky, you were an astronomer. But everything has gotten so complicated. Now we have astrophysicists, and cosmologists, planetary geologists, and even exobiologists. Who does what, and how do they all interact with one another. If you want to go into space research as a career, which one should you choose?
Astronomy Cast at Dragon*Con 2012: Space Money
We’ve probed the deepest recesses of the universe, landed spacecraft and humans on other planets and moons but, face it, all of this exploration is expensive. Just a single spacecraft can cost billions. So, who pays for all this stuff?
Ep. 270: Inertia
An object at rest tends to stay at rest. An object in motion tends to stay in motion. Isaac Newton dismantled the traditional idea that objects would tend to slow down over time, and described the concept of inertia: the amount an object will resist changes in its motion.
Ep. 269: Mass
Last week we talked about energy, and this week we’ll talk about mass. And here’s the crazy thing. Mass, matter, the stuff that the Universe is made of, is the same thing as energy. They’re connected through Einstein’s famous formula – E=mc2. But what is mass, how do we measure it, and how does it become energy, and vice versa.
Ep. 268: Energy
Our entire civilization depends on energy: getting it, converting it, burning it, and conserving it. But how do physicists think about energy? How do they measure and quantify it. And what is energy’s special relationship with mass?
Ep. 267: Infinities
Forever is a funny thing. Today we’re going to talk about infinities. That’s right, all the different kinds of possible infinities. How you add them, subtract them, and use them to think about the scale of the Universe.
Ep. 266: Archimedes
It’s time to look deep into history to the birthplace of modern mathematics – Ancient Greece. And the most famous mathematician of the time was Archimedes. We use many of his mathematical theories and inventions to this day; others are steeped in legend and mystery.
Ep. 265: Arthur Eddington
We can thank Arthur Eddington for much of our current understanding of stars. He provided some of the breakthrough concepts that explain what’s going on, deep inside the hottest places in the Universe. Sadly, the spacecraft associated with his name wasn’t so successful.
Ep. 264: Hazards of Spaceflight
We hold all these romantic notions about humans exploring the Solar System, turning humanity into a true space-faring race. But the cold hard reality is that space, really the entire Universe, is trying to kill you. Any humans venturing out into space will face all kinds of hazards.
Ep. 263: Radioactive Decay
Nothing lasts forever, even atoms. Heavier elements decay into lighter elements, releasing energy as radiation. But thanks to this radiation, astronomers can get a glimpse into what’s going on inside distant start. Let’s take a look at the whole process of radioactive decay, the different events that happen, and how humans use this fundamental force of nature for our own needs.
Ep. 262: Solar Sails
Wouldn’t it be cool to explore the cosmos, powered only by sunlight caught by your shimmering solar sail? It sounds like science fiction, but it’s serious science – a test sail has even been sent to orbit. It might even be a way to travel from star to star.
Ep. 261: Lasers and Masers in Astronomy
Last week we introduced the science of lasers and masers. This week we apply that knowledge to our favourite field: astronomy. Learn how naturally forming masers teach us about the cosmos, and how the artificially produced lasers help us gather better science.
Ep. 260: The Technology of Lasers and Masers
Just when you think you understand it, light will do some amazing things. Just look at the discovery of lasers, and their use in almost every technology you can think of: from cutting, to transmitting information to, yes, astronomy. And nature has figured out its own version of laser technology, called the maser, which has kept astronomers puzzled and excited for years.
Ep. 259: Exploration of Venus
Mars gets all the attention, but you might be surprised to know how much Venus has been explored. From initial telescope observations and the early flyby missions, to the landers… yes landers and orbiters. We know quite a lot about Venus, but the planet sure didn’t give up its secrets easily.
Ep. 258: Viking Landers
Last week we talked about the orbiter portion of the Viking Missions. But that was only half the adventure. Each Viking spacecraft carried a lander as well, which touched down on the surface of Mars, searching for evidence of past and current life. And what they discovered is still up for debate.
Ep. 257: Viking Orbiters
Spirit, Opportunity and Curiosity get all the news now, but it was NASA’s Viking Missions that gave us our first close up view of the surface of Mars. These twin missions, both made of orbiter and lander set the stage for the exploration of Mars, demonstrating that we could actually reach the surface of Mars, and study the soil up close. Today, let’s talk about the Viking Orbiters.
Ep. 256: Resolution
When it comes to telescopes, astronomers really just care about resolution: how much can you see? Your resolution defines how much science you can get done, and it depends on your gear, wavelength, and conditions. Putting a telescope in space really helps too.