We did a wildly popular three part series about the center, size and shape of the Universe. But every good trilogy needs a 4th episode. This week we look at age of the Universe. How old is the Universe, and how do we know? And how has this number changed over time as astronomers have gotten better tools and techniques?
AstronomyCast
Questions Show: Stellar Roche Limits, Seeing Black Holes, and Water on Mars
This week we find out when stars get torn apart from gravity, how we can see supermassive black holes, how liquid water could have existed on Mars in the past, and much 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. Please include your location and a way to pronounce your name.
Ep. 121: Spacesuits
As we’ve mentioned before, the Universe is trying to kill you. And for astronauts, that’s truer than ever. One step out into the vacuum of space would be a world of hurt for an unprotected astronaut: the freezing cold temperature, the lack of atmospheric pressure, and the deadly radiation, just to name a few hazards. That’s why the smart astronaut always puts on a spacesuit first. Let’s take a look at the smallest spaceship around.
Ep. 120: The Christmas Star
With Christmas just around the corner, we thought we’d investigate a mystery that has puzzled historians for hundreds of years. In the bible, the birth of Jesus was announced by a bright star in the sky that led the three wise men to his birthplace. What are some possible astronomical objects that might look like such a bright star in the sky? And were there any unusual events that happened at that time?
Questions Show: Different Fields of Astronomy, Our Sibling Stars, and Hidden Lagrange Points
This week we find out the difference between an astronomer, an astrophysicist, and a cosmologist, the search for the stars that shared our nebula, hidden objects in Lagrange points, and much 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. Please include your location and a way to pronounce your name.
Ep. 119: Robots in Space
Space is totally inhospitable. If the freezing temperatures don’t get you, the intense radiation will kill you. Or the vacuum, or the lack of breathable atmosphere, or meteoroid impacts. Well… you get the idea. That’s why most space exploration is done by hardy robots. They don’t need to eat, drink or breathe. They get their energy from the Sun, and they’ve proven they’ve got the right stuff to explore every planet and major moon in the Solar System. Let’s hear it for the space robots.
Questions Show: Distance in Space, Changing Earth's Orbit, and Different Sized Stars
This week we find out the distance between Betelgeuse and Bellatrex, how astronomers measure distance between objects, the possibility that an object could mess up the orbit of Earth, and the reason for different sizes of stars. 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. 118: Sky Surveys
In the old days, astronomers had to beg for telescope time. They’d put together a proposal, convince observatories to gather data for them, crunch that data and release the results. No telescope, no results. But everything’s different now. Fleets of robotic telescopes constantly scan the skies, building up a vast database of raw data about the Universe. Anyone who wants can access the information through the Internet, download what they need to do real science. No telescope necessary. Let’s look at the development of sky surveys, and how they’re changing how astronomy gets done.
Ep. 117: Time
Today, time rules our lives. We live each day with the moments broken up into hours, minutes and seconds. We never seem to have enough time. But can you imagine not being able to tell time at all, where the movements of the Sun and the stars was the only way to know what time it was? Let’s learn about the history of time, methods of telling time, and Einstein’s historic discovery that time isn’t as fixed as we thought it was.
Ep. 116: Molecules in Space
As part of her trip to England, Pamela had a chance to sit down with Oxford astrophysicist Chris Lintott and record an episode of Astronomy Cast. From the first stars to the newest planets, molecules and the chemistry that allows them to form affects all aspects of astronomy. While most astronomers group molecules into three bins of hydrogen, helium and everything else, there are a few who do proper chemistry by studying the sometimes complex molecules that form between the stars.
Ep. 115: The Moon, Part 3: Return to the Moon
It’s time for a third lunar chapter. We’ve talked about the physical characteristics of the Moon, and the exploration. Now we’re going to talk about the plans to return to the Moon. From the upcoming lunar reconnaissance orbiter to the plans to have humans set foot on the Moon again, for the first time in more than 50 years.
Questions Show: Spiral Arms, Seismic Waves on the Sun, and our Favorite Gear
This week we explore galactic spiral arms, seismic quakes on the Sun, and our picks for astronomy gear. 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. 114: The Moon, Part 2 – Exploration of the Moon
Let’s continue on our journey to the Moon. Last week we talked about the physical characteristics of the Moon, its appearance in the sky and how it interacts with the Earth. This week we’re going to take a look at how scientists have expanded our understanding of the Moon. From ancient astronomers using nothing more than their eyes and the first telescope observations of Galileo to the exploration by robotic spacecraft. And of course, the first tentative steps by the human explorers of the Apollo program.
Questions Show: Ice in Space, Expansion of the Universe, and Death from the Skies
Another week, another batch of questions. If ice disappears in your freezer, how can it last in space? How can the Universe be expanding faster than the speed of light? And what is the risk from a coronal mass ejection in an airplane? All this and even more questions. 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. 113: The Moon, Part 1
Hey, here’s a topic we haven’t really gotten around to yet… the Moon. Today we look at our closest astronomical companion: the Moon. What impact does the Moon have on our lives, where did it come from, who walked on it, and are we ever going to walk on it again? We’re going to learn about the phases, the tides, and even a little bit about NASA’s plans to send humans back to the Moon.
Questions Show: Orbit of the Planets, Green Stars, and Oort Cloud Contamination
We’re back to a theme-less questions show. We’re right across the Universe this time. Why are the planets lined up in a nice flat plane? Why are there no green stars? And is the Oort Cloud contaminating our understanding of the cosmic microwave background radiation? 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. 112: Death From the Skies, Interview with Phil Plait
We say it all the time here on Astronomy Cast: the Universe is trying to kill us. This week, Pamela is joined by Dr. Phil Plait to discuss his new book, “Death from the Skies”. Phil and Pamela talk about asteroid strikes, solar flares and gamma ray bursts.
Questions Show: Relativity, Relativity and More Relativity
Everyone loves a theme. And this week we’ve collected together some of your questions about relativity. More light speed spacecraft, twin paradoxes, and the mixing up of gravity, time and mass. 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. 111: Nebulae
When you think about the best pictures in astronomy, almost every one is a nebula; the pillars of creation in the Eagle Nebula, or the complex Helix Nebula – or my personal favourite, the Ring Nebula. They’re beautiful, wispy clouds of gas and dust that signify both the birth and death of stars. Today we give tribute to nebulae.
Questions Show: Galactic Dust, the Speed of Photons, and the Big Bang Calculations
Another week, another roundup of your questions. This week listeners asked: what is galactic dust anyway, and where does it come from? Why can photons move at the speed of light? And how can astronomers know what happened right after the Big Bang? 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. Please include your location and a way to pronounce your name.
Ep. 110: The Search for Extraterrestrial Intelligence
You know what this show needs? More aliens. Since we don’t seem to have any visiting right now, we’re going to have to find some. SETI is an acronym. It stands for the Search for Extraterrestrial Intelligence. But there’s more to SETI than just putting up a radio telescope and hoping to catch a glimpse of an alien television broadcast.
Questions Show: Alignment with the Galactic Plane, Destruction from Venus, and the Death of the Solar System
Another week, another roundup of your questions. This week listeners asked: are we all going to die in 2012 when the solar system passes through the galactic plane? Did Venus make the Moon? And what will extraterrestrials see when the Sun is dead and gone? 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. 109: The Life of Other Stars
Last week we looked at the complete life of the Sun, birth to death. But stars can be smaller, and stars can get much much larger. And with a change in mass, their lives change too. Let’s start the clock again, and see what happens to the smallest stars in the Universe; and what happens to the largest.
Questions Show – Running Out of Gravitons and Hitting the Brakes at Light Speed
Another week, another roundup of your questions. This week listeners asked: if forces are communicated through particles, can we run out? If you were traveling at light speed, when would you know to stop? 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. 108: The Life of the Sun
We’ve talked about the Sun before, but this time we’re going to look at the entire life cycle of the Sun, and all the stages it’s going to go through: solar nebula, protostar, main sequence, red giant, white dwarf, and more. Want to know what the future holds for the Sun, get ready for the grim details.