Even casual observers of the night sky are familiar with the winter constellation Orion. It's two brightest stars, Rigel and Betelgeuse and its three belt stars make it an easy one to spot. But one of them has dimmed dramatically in recent months, the red supergiant star Betelgeuse.

Dave visits with neuroscientist, cognitive psychologist, musician and all-around amazing guy, Daniel Levitin. His book This is Your Brain On Music spent more than a year on the New York Times Bestseller list and his latest, Successful Aging is already on the top ten for this year's list. Levitin's biography thus far is nothing short of amazing. He's helped produce and consult on musical projects ranging from Steely Dan, Blue Oyster Cult and Joni Mitchell (just to name a few!) to being the music

Dave talks with two of the Deputy Project Scientists deeply involved with the Curiosity Rover, which has been exploring Gale Crater since 2012, and the new, yet to be named, Mars 2020 Rover that will be launching this July. Abigail Fraeman is the DPS for Curiosity and explains how the mobile science laboratory has furthered our understanding of how Mars was once a planet that was suitable for primitive microbial life.

In this episode, Dave is going to the dogs. Literally. But that's OK with him because Dave loves dogs and dogs love him and now, thanks to Dr. Clive Wynne, he can prove it. Dr. Wynne, a researcher in animal behavior at Arizona State University, is the author of the new book, Dog is Love: Why and How Your Dog Loves You. From Pavlov's dogs (you'll find out there's more to that story than wringing a bell) to modern research using MRI machines, Wynne's book is an exploration of a simple and

Dave visits with some very special friends! Amy Bean, Tracy Cernan, and Gwen Griffin all grew up inside the Apollo Moon program during the late 1960s and early 70s. Amy and Tracy's Dad's were among the 12 men who are the only ones to have ever walked on another world -- The Moon.

Blue Dot looks back at 51 years of the Apollo program with a look at the very first mission to the Moon -- Apollo 8. Considered by most space historians as the most dramatic and bold mission of the entire lunar program, astronauts Frank Borman, James Lovell and William Anders became the first human beings to leave ride the powerful Saturn V rocket, leave Earth's gravitational well and see the backside of the Moon with their own eyes.

Longtime listeners to Blue Dot know that Dave has a lifelong fascination with the Moon from its exploration to its role in eclipses. But how did our companion world come to be? Since the Apollo missions brought back lunar samples, the most accepted idea is called the "Giant Impact Hypothesis" but the notion has its flaws -- mainly that if a Mars-sized object actually did hit the Earth and create the Moon, where is the evidence in the Moon rocks which are isotopically identical to Earth's?

In this episode, inspired by our good friend Alan Stern, the Principal Investigator for the New Horizons Spacecraft, we examine a question that has vexed astronomers, planetary scientists and 5th graders, for decades: " What exactly is a Planet ?" And more importantly, why should we care about definitions like this in science.

In this very special episode, Dave talks to the daughter of the man he likes to call "the patron saint of Blue Dot," Carl Sagan. Sasha Sagan was only 14 when her father passed away in 1996 and his loss is central to the theme of her new book For Small Creatures Such As We: Rituals for Finding Meaning in Our Unlikely World .

For scientists in the fields of chemistry, medicine and physics, there is the Nobel Prize and all the accolades that come with it. But for scientists in the environmental sciences, the Tyler Prize was created by Ann and John Tyler in 1973 to recognize scientists making world class contributions to the fields of science that most impact our understanding of the Earth's ecosystems.