Celebrate the Fall Equinox

It’s hard to believe that summer is over and fall is right around the corner. Friday, September 23rd, the fall equinox will be upon us and if you wake up early enough you can greet it at 5:05 am. You won’t notice anything different, but the earth will have arrived at a point in its orbit around the sun, signaling fewer minutes of daylight as we move toward the Winter Solstice in December. If you are awake early in the morning that Friday there are great things to be seen, such as the waning crescent moon, which will be positioned below Mars. Also, we are identifying so many earth-like planets now, but what are the criteria for these discoveries? Scientists look at the mass of the object and how close that object is to the habitable zone of the solar system. There is also new research on how stars are built. All this and more on this week’s Sky Talk.[audio: st20110919.mp3]