AstronomyCast 255: Observing Hydrogen, by Fraser Cain & Dr. Pamela Gay

Hydrogen is the most common element in the Universe, formed at the beginning of everything in the Big Bang. It's the raw material of stars, gathering together through mutual gravity into vast nebulae. Astronomers can learn so much looking for hydrogen in the Universe. Here's why, and how they do it.

Another week, another space roundup. This week we talk about the redefinition of the term "Earthlike", salty soil on Mars, how you can participate in SETI, asteroid dust from Hayabusa, and the dangers of a warp drive.

Light can do some pretty strange stuff, like pass through objects and bounce off them; it can be broken up and recombined. In fact, everything we "see" is actually the end result of reflection and refraction of light. Time to understand how it all works.

AstronomyCast 253: Rayleigh Scattering, by Fraser Cain & Dr. Pamela Gay

Next time a kid asks you, why is the sky blue? Answer them: because of Rayleigh scattering. If they’re not happy with that answer, feel free to expand based on the knowledge we’re about to drop today, right into your brain.

AstronomyCast 251: Messier Objects, by Fraser Cain & Dr. Pamela Gay