astronomy cast qt 3 pt. 1

"What if Something Were Different?"
In this episode of Astronomy Casts, Fraser and Pamela discuss what would happen to us and our solar system if several things were different. The first topic that they discuss is the density of our galaxy. It turns out that galaxies with large densities essentially eliminate any star formation. This would eliminate some constellations and nebula such as the Orion Nebula and the Pleiades. Conversely, if our galaxy had its matter spread to thin the sky would essentially be empty. The next thing they discussed was the formation of our sun. If our sun was formed earlier, close to the big bang, then our sun would have lacked a lot of the metals that helped cool it down. Without cooling off, the sun would have had a much shorter life and we would possibly not exist. If the sun had tried to form trillions of years later, it may not have been possible. Star formation continues and matter is used, but eventually it is spread too thin for there to be continued star formation. The universe is continually expanding so eventually star formation will cease to exist. They then talked about the location of our solar system in the galaxy. If we were closer to the more turbulent center of the galaxy, the integrity of the solar system could be ruined by passing stars. These stars could affect planets in the outer region by changing their orbit or even the star that they orbit around. Being on the outside of the galaxy could lead to a dearth of metals that could inhibit planetary formation. This would have prevented our solar system from ever truly developing. The two primarily discussed how the solar system and our lives would be affected if our location and surroundings and even time frame were changed.

"Carina Constellation"
In this episode, Fraser and Pamela discuss the Carina Constellation. The first discuss how it is part of one of the greatest star forming parts of the universe. Carina was also a group of stars that attempted to go supernova but failed to do so. The went off on an interesting tangent about the location of someone on earth to their view of the sky. People in the southern hemisphere get a different view of constellations than those in the north. We are able to view Carina because we are far enough south. The brightest star currently is Eta Carinae. The nebula is able to viewed during July and August and appears to just be a fuzzy area. The brightest star in the constellation used to be alpha carinae, but that was due to a process where the star almost exploded but did not quite go supernova. The Carina nebula is a large area, appearing to be about 7 times the size of the moon, and gives off red light. This part of the constellation is the part that is responsible for the continued formation of stars. Eta Carinae, the almost supernova star is imminent to explode for real, but imminent is defined as tens of thousands of years. Finally, the constellation has two double cluster stars in its system.