Fraser Cain
Universe Today
Dr. Pamela Gay
CosmoQuest
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. But they were very good robots.
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.
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?
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 here are some scary stories to spook it up a notch.
Recent Episodes
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...
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...
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...
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...
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...
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...
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?...
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...
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...
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? Astronomy Cast at Dragon*Con...
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...
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...
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. 268: Energy Jump to Shownotes...
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. 267: Infinities Jump to Shownotes Jump to...
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....
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...
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...
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...
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. 262:...
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....