Cowboys & Aliens are Coming!
July 29, 2011 --
If aliens are going out of their way to kick up dust in the Wild West, as they do in the upcoming movie "Cowboys & Aliens," they must be coming from somewhere. Life could take root on a moon or a meteorite. But to nurture the kind of life that could destroy our saloons and harass our livestock, a planet might be the most suitable. So far, Kepler, a NASA orbiting telescope that searches for planets beyond our solar system, has detected over 1,200 exoplanets. Surely there must be a few candidates among this group that could meet some of the most basic requirements to host life? Explore some far-out worlds that could support aliens, be they cattle-rustling characters or a more peaceful people.
First, let's lay out some basic criteria. Kepler hasn't identified many rocky worlds and a solid surface is essential for life to take root. Size matters: The mass of the planet helps astrophysicists infer what it's made of. Some planets are Earth-sized. Others are several times the size of our planet. And then there are gas giants, which can range from "Neptune sized" to "super-Jupiters." Orbit: To support life, a planet must be in a stable orbit around its star -- no planets with wonky orbits that will eventually dump them into their star for a fiery death. Goldilocks Zone: This is a region not too hot or too cold that gives the planet enough distance from its parent star to have liquid water, key for life. Loner Stars: Single stars make better parents. In 2010, a pair of closely orbiting binary stars was spotted surrounded by what could be the debris of former planets. Unknowns: Some factors for life can't be confirmed one way or the other from the data available about extrasolar planets. These include: water, chemical compounds such as ammonia; a nitrogen-rich atmosphere; a magnetic field to repel solar and cosmic radiation; and more. BUT, some planets do have a head-start, beginning with Gliese 581D.
Located a mere 20 light-years away, practically our backyard in cosmic terms, Gliese 581d is situated on the "outer fringes" of the Goldilocks zone, orbiting a red dwarf star. The planet may be warm enough and wet enough to support life in much the same manner as Earth. It might also contain a thick carbon atmosphere. If we ever need a new Earth and have the means to get there, Gliese 581d may be our best bet for now.
When it was first detected and reported last year in Astrophysical Journal, Gliese 581g appeared to be the perfect candidate for a true "Earth-like" planet. Located in the same star system as Gliese 581d (and detected earlier), Gliese 581g seemed to be the right size and located within a habitable zone away from its parent star. Gliese 581g was said to have three times the mass of Earth, making it possible for the planet to hold an atmosphere. However, since its discovery, follow-up studies have alleged that Gliese 581g might have been a false alarm. In other words, the planet might not exist at all.
Dubbed a "waterworld" and located a mere 42 light-years from Earth, GJ 1214b orbits near a red dwarf star about one-fifth the size of our sun. What makes this planet unique is that it appears to be primarily composed of water, although GJ 1214b is 6.5 times the mass of Earth and 2.7 times wider, which classifies it as a "super-Earth." This planet also has a steamy atmosphere composed of thick, dense clouds of hydrogen, which, although it might not the case with this planet, could incubate life.
Situated 150 light-years from Earth, HD 209458b is a planet that holds traces of water vapor in its atmosphere, and also contains basic organic compounds that, on Earth, foster the development of life. But there are two factors working against HD 209458b as a suitable habitat. The planet is very hot due to its close proximity to its parents star, and it's a gas giant, so no solid surfaces.
If Kepler-10b were located further from its parent star, it might have had a chance of hosting life. Kepler-10b was the first "iron-clad proof of a rocky planet beyond our solar system" back in 2001. It was even dubbed the "missing link" of extrasolar planetary research. When it comes to the search for life, though, Kepler 10-b is missing a lot of other ingredients -- just minor things like water or an atmosphere.
When venturing to a new star system to explore the possibility of extraterrestrial life, trying a star that has already shown itself to nurture planets -- even if they're not the kind you're looking for -- could be a promising strategy. Project Icarus, an ambitious five-year study into launching an unmanned spacecraft to an interstellar destination, has identified two stars located within 15 light-years that might fit the bill: "epsilon Eridani, a single K star 10.5 light-years away, and the red dwarf GJ 674, 14.8 light-years away." Indirect evidence has also shown that epsilon Eridani may already hold smaller worlds scientists simply haven't detected yet. Also, red dwarf star systems generally may be a safe haven for life.
Are We Alone?
Taking into account the number of exoplanets that have been detected, as well as the vastly greater number that are estimated to be out there, some astrophysicists are convinced that extraterrestrial life is inevitable. After all, the Milky Way may be loaded with as many as 50 billion alien worlds. Some even think we'll find alien life by 2020. Others, however, say it may not exist at all. Recently, astrophysicists David Spiegel of Princeton University and Edwin Turner from the University of Tokyo suggested we might be alone in the universe, based on their interpretation of the Drake equation, a formula meant to determine loosely the probability of the existence of life beyond Earth. According to their analysis, just because life on Earth took shape early, endured and prospered doesn't mean the same process would naturally and inevitably occur elsewhere in the universe. Discovering life elsewhere, however, would be the only means of settling this debate. Unless the aliens find us first, of course.
Earlier this week a mysterious, glowing teardrop-shaped object was seen high in the sky above Phoenix.
WPTV News Channel 5 asked its readers, “What was that floating (sometimes stationary) bright, glowing object hovering over the Valley Monday evening? Did you see it? Some thought it was a UFO, a weather balloon or even an alien spaceship.”
Eventually the National Weather Service was asked about it, and their response poured cold water on conspiracy theories about top-secret military craft and extraterrestrial visitation. The strange sight has nothing to do with UFOs or aliens. Instead it’s a HASP 643N — a High Altitude Student Platform balloon sent up to research things like wind patterns and air quality.
It’s a project of the Columbia Scientific Balloon Facility, which according to its web site, launches large, unmanned, high-altitude research balloons — and recovers the experiments they carry — for NASA and universities around the world.
Though the Columbia balloon facility is located in Palestine, Texas, the former-UFO HASP balloon was launched from Fort Sumner, N.M. — not far from Roswell, site of a famous 1947 crash of either a Cold War spy balloon project or an alien spacecraft — depending on whom you believe.
Other Phoenix UFOs
This is only the latest of many purported UFO reports near or over the city of Phoenix. In late 2011, for example, four bright lights were seen and videotaped during a high school football game in Scottsdale. The strange lights, which were seen by hundreds of people and videotaped by at least two of them, seemed to move slowly in the sky, sometimes blinking randomly.
The entire sighting lasted for about a minute and a half. The video was posted to YouTube, where within days it became one of the top stories on Yahoo News, sparked “a national mystery” and garnered over 50,000 views.
The mystery was soon solved when a local reporter identified the mysterious lights as four members of a skydiving team, the Arizona Skyhawks, who jumped with bright magnesium flares for a Halloween show.
In 2008, another set of mysterious lights were sighted. Hundreds of Phoenix residents reported four bright red lights in the sky at about 8 p.m. Those turned out to be a hoax created by road flares tied to helium balloons.
Robert Sheaffer, a UFO investigator with “Skeptical Inquirer” magazine and author of the “Bad UFOs” blog, told Discovery News, “It’s remarkable how so many people, when they see lights in the sky, immediately jump to the conclusion that they might be seeing (an alien spacecraft) … In reality there are many different possible explanations for lights in the sky, all of them more likely than alien visitors.”
It’s a good reminder that just because one or more people can’t identify something in the sky doesn’t mean that it’s unknown or unexplainable.
Indeed, there may be more UFO sightings still to come. Another half-dozen HASP balloon launches are slated for this month, and — depending on weather patterns and where you live — may end up in the skies over your hometown.
Photo: Screen capture/3TV/azfamily.com