Northern Rockies Skies for July: The Stars of Summer
A monthly look at the night skies of the northern Rocky Mountains, written by astronomers Ron Canterna, University of Wyoming; Jay Norris, Challis, Idaho Observatory; and Daryl Macomb, Boise State University.
July is a wonderful time to go star searching, and there are many very bright stars that make this an exciting activity.
First and foremost, immediately after sunset, almost directly overhead, the third brightest individual star in in the night sky appears -- the orangish giant Arcturus. It is the first bright star along the imaginary arc from the handle of the Big Dipper to the star Spica in Virgo. Spica, a blue giant, is the 15th brightest star in the sky.
Almost directly east, on the south horizon, you will see Antares, the 16th brightest star in the sky. Antares is a red giant and, along with Aldebaran (Taurus), Fomalhaut (Piscus Austrinus) and Regulus (Leo), forms the "Royal Stars of Persia."
Above the eastern horizon are the summer triangle stars Vega (Lyra), the fifth brightest star in the night sky; Deneb (Cygnus), the 19th brightest star in the sky; and Altair (Aquila), the 12th brightest star.
So enjoy star hunting this July, but don't confuse those stars with two prominent planets: Mars is near Spica, and Saturn is just to the west of Antares. All you early risers, look for this month’s morning star, Venus. The Delta Aquarids meteor shower peaks July 28-29. Happy star and planet gazing.
July 2014 Interest: Fermi's Paradox
(Best URL: http://en.wikipedia.org/wiki/Fermi_paradox)
In 1950, the famous nuclear physicists Enrico Fermi and Edward Teller were walking to lunch when they began a conversation centering on the odds that any intelligent civilizations existed beyond Earth, and whether or not such a civilization could visit, or had already visited, our planet.
The kernel of Fermi's paradox is that even if only a very small fraction of the stars in our own Milky Way galaxy have habitable Earth-like planets, then some advanced civilizations capable of interstellar travel at just a small fraction of the speed of light should already have colonized the entire galaxy on a time scale of only a few tens of millions of years, whereas the galaxy is nearly as old as the universe itself, about 13.6 billion years.
Fermi was famous for making good back-of-the-envelope estimates. His simple calculation indicated the odds were high in favor of contact, and so he reportedly exclaimed, "Where are they?" -- given that we had, and still have, no clear, verified evidence of contact or visitation from another world.
Since that conversation between Fermi and Teller, astrophysicists and biotechnologists have greatly refined our understanding of stars, including aspects relevant to planetary systems possibly capable of supporting life. Additionally, logicians have exhaustively examined more detailed and deeper aspects of Fermi's argument. The bottom line is that a large variety of resolutions to Fermi's paradox have been suggested, some more reasonable than others, but none have been demonstrated to be the actual resolution.
A good part of the difficulty is that we have only the sample of one -- life on Earth -- upon which to base our extrapolations. In addition to attempts to detect signals from other planetary systems (the Search for Extraterrestrial Intelligence program) and searches for Earth-like planets in relatively nearby stellar systems (the Kepler satellite), many hypotheses have been advanced that purport to explain absence of contact. Among them are:
-- Within the galaxy, intelligent civilizations are few or exist for brief periods, or we are the first.
-- Intelligent life extinguishes itself or any life that it finds, or natural phenomena (e.g., supernovae) destroy stellar systems.
-- Civilizations are too far apart to reach each other, due to the finite speed of light.
-- Communication methods are vastly different than ours.
-- Intelligent civilizations reach a technological singularity or stopping point, obviating further development for whatever reason.
-- It is imprudent or dangerous to communicate.
-- Technology tends toward closed systems rather than space travel.
-- They are here, but we do not recognize their form -- or their presence is hidden.
In future installments, we will discuss some of the more probable and consistent solutions to Fermi's paradox.
To view this month’s sky chart, click here.