Iapetus-Saturn

Yin Yang Moon

Iapetus is a moon of Saturn known for two distinctive features. One is that it has a two-tone coloration, where roughly half of the moon is a dark, reddish-brown color while the other half is white and almost as bright as Jupiter’s moon Europa. It’s not entirely clear what gives Iapetus is yin yang coloring, but the most popular view is that it is cause by sublimation of the moon’s warmer side. Ice evaporates away leaving the dark remnant material. We know, for example, that the dark layer is no more than a foot thick, and has a bright layer underneath it. Read more

Credit: NASA/JPL-Caltech

Young and Brilliant

Young galaxies typically go through a period of rapid star production. For example, dusty starburst galaxies produce stars so rapidly that it would consume all of its gas and dust in about 10 million years at that rate. But before that early star production period, a galaxy also has a period of rapid formation into a galaxy. In this period the central black hole of the galaxy is particularly active. As a result these galaxies are bright in the infrared, and are known as luminous infrared galaxies (LIRGs). Read more

Credit: NASA/ESA/G. Bacon

Hungry Like the Wolf

A Wolf-Rayet star is an old massive star on its way to becoming a supernova. They are distinguished by extremely strong stellar winds and their spectral lines tend to show they are rich in helium, but don’t contain much hydrogen. It’s generally been thought that the lack of hydrogen in Wolf-Rayet stars is due to the strong solar winds pushing away the light element, but a new paper in MNRAS finds evidence of an alternative method, which is the capture of hydrogen by a companion star. Read more

episode11

Biodiversity/Kepler’s Laws

We are in the midst of a great die off. If humanity continues its industrial practices at their current rates, we could lose a quarter of the planet’s plant and animal species in the next hundred years. On our show today is Dr. Christy Tyler, an Associate Professor of Environmental Science at the Rochester Institute of Technology. She’s going to share with us all the ways biodiversity impacts life on Earth.  In the second half of our show we’ll talk about the historical staying power of Kepler’s laws of planetary motion.

Host: Brian Koberlein
Guest: Christy Tyler
Producer: Mark Gillespie
Music: Marcus Warner

The One Universe at a Time Podcast is produced at the Rochester Institute of Technology with support from the RIT College of Science.

Credit: NASA, ESA/Hubble and the Hubble Heritage Team.

The Illusion of Reality

One of the most impressive aspects of astronomy is the stunning visuals. These amazing color images inspire our love of the cosmos, and are a perennial hit on social media. They also aren’t real, at least in the sense of being an accurate representation of how celestial objects actually appear to the human eye. They are more art than science, providing an illusion of reality. Read more

Credit: NASA

The Left Hand of Darkness

One of the basic assumptions of cosmology is that the universe is on average the same everywhere. That is, it is uniform and isotropic. This assumption seems to hold up quite well, but naturally there are studies done that look for violations of this assumption. Every now and then a research project will find what seems to be a violation of this assumption, but they generally don’t pan out when examined more closely. But there are aspects of the universe that aren’t symmetrical, and one of the biggest is known as matter/antimatter asymmetry (or baryon asymmetry). Read more

stars

Red Hot Vacuum

One of the common tropes in astronomy is a comparison of our Sun to other stars. It’s a great way of showing just how tiny we are. Betelgeuse, for example, has a radius more than 1,100 times that of the Sun. In an image comparing stars, our Sun is easily reduced to a tiny pixel among giants. But such an image is also a bit misleading. While the relative sizes of these images are typically accurate, they ignore the more important aspect of a star, which is its mass. Read more