EXOPLANETS @ JIMCOLYER.COM Exoplanets are planets circling stars other than our sun. 1797 have been confirmed as of June, 2014. There are no doubt billions in the Milky Way galaxy. 51 Pegasi was the first main-sequence star around which an exoplanet was discovered. That was in 1995. Geoff Marcy and his team at the University of California Berkeley are at the forefront of exoplanet research. So far, it has been mostly Super-Earths and large gas planets called Hot Jupiters. But the Kepler Space Telescope found Earth-size planets, and some are in their stars habitable zones, where it is not too hot and not too cold and liquid water is possible. Kepler used the transit method. It measured a stars dimming as planets crossed in front of it. Most exoplanets have eccentric orbits. Many orbit close to their stars. Astronomers are looking for an Earth twin, a rocky planet taking about one Earth year to complete its orbit. Astronomers at the European Southern Observatory in Chile claimed to have found Earth-like planets in Gliese 581 c and d. They lie in or near their stars habitable zones. Gliese 581 is 20 light-years away. Kepler 22-b may be an Earth-like planet in terms of size and temperature. It is in the Goldilocks zone at 600 light-years. Alpha Centauri is the closest star at 4.4 light-years. It is a triple star, and an exoplanet orbits Alpha Centauri B. It is similar to Earth in mass but too near its star for life. The planet was detected at the ESO using the radial velocity method. The stars wobble caused by the planets gravitational tug was measured. It is analogous to a large man dancing with a small woman. He may twirl her around, but she will have an effect on him. It makes sense that stars closest to our sun would be the best candidates for having Earth-like planets. Gliese 667 is a triple star 22 light years away in the direction of Scorpius. Gliese 667 C is a system with 7 planets, 3 of which orbit in the habitable zone. They are Super Earths, larger than Earth but smaller than the gas giants. According to the ESO, these planets fill the habitable zone of Gliese 667 C. Gliese 667 Cs habitable zone is smaller than that of the sun because Gliese 667 C is cooler. Its planets orbit close. Wilhelm Gliese (ɡli-zə) was a German astronomer known for his 1957 Catalogue of Nearby Stars. The James Webb Space Telescope will be launched in 2018, and will look for biosignature gases in the atmospheres of exoplanets. It is obvious that our solar system is not unique, and the search is on for extragalactic planets, planets in galaxies such as M31. Extraterrestrial life - Astronomers and other scientists are in a desperate search for life beyond our planet. The question Are we alone? is more relevant now than at any time in history. Curiosity is looking for signs of life on Mars. The field of astrobiology has opened up even though nothing has been found. If there were organic molecules in the protoplanetary disk surrounding the sun, then life may exist elsewhere in the solar system. Jupiters moon Europa may be suitable for life as well as Saturns moons Titan and Enceladus. There may be oceans under ice. Microbes were found under ice in Antarctica’s Lake Vida. The discovery of life in this extremely cold habitat makes us ponder the potential for extraterrestrial life on Europa. It is thought that liquid water once flowed on Mars and may still exist beneath its surface. Mars may have been warmer in the past. No life has been confirmed. NASA scientists want to find extraterrestrial life so bad that they tend to jump to conclusions. I would guess that in some cases they even lie. SETI (Search for Extraterrestrial Intelligence) uses radio telescopes like Arecibo in Puerto Rico. SETI has failed to detect intelligent radio signals in more than five decades of trying. Even if there are advanced ET civilizations, they may not be transmitting in our direction. And even if they are, we may not be able to interpret their signals. Because of the distances involved, any radio signals would come from the remote past. 6 elements are basic to life on earth: carbon, oxygen, hydrogen, nitrogen, phosphorus and sulfur. Scientists assume these elements would be the basis of alien life. They also assume that alien life would be DNA based. Water is the perfect solvent for biochemistry to take place. Perhaps life elsewhere in the Milky Way or in other galaxies would not be based on DNA. DNA is the hereditary material in cells famous for its double helix. Science fiction depicts aliens with humanoid or reptilian traits. Aliens are pictured as green or grey and having large heads. The term UFO was coined in 1947, after the Roswell incident and the alleged sighting of flying saucers by Kenneth Arnold. Conspiracy theories abound! Ufologists claim the government is involved in a cover-up. They want disclosure while citing the secrecy of Nevadas Area 51. The White House Office of Science and Technology Policy posted this on the White House website: “The U.S. government has no evidence that life exists outside our planet, or that an extraterrestrial presence has contacted or engaged any member of the human race. In addition, there is no credible information to suggest that any evidence is being hidden from the public eye.” The ancient aliens of Erich von Daniken and Giorgio Tsoukalos are a mix of space age mythology, folklore and science fiction. JIMCOLYER.COM
Posted on: Tue, 06 Jan 2015 01:04:05 +0000
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