NASA's Kepler Provides Insights on Enigmatic Planets

Artist's view of a Earth-size rocky exoplanet. Image credit: NASA/JPL-Caltech

More than three-quarters of the planet candidates discovered by NASA's Kepler spacecraft have sizes ranging from that of Earth to that of Neptune, which is nearly four times as big as Earth. Such planets dominate the galactic census but are not represented in our own solar system. Astronomers don't know how they form or if they are made of rock, water or gas. The Kepler team today reports on four years of ground-based follow-up observations targeting Kepler's exoplanet systems at the American Astronomical Society meeting in Washington. These observations confirm the numerous Kepler discoveries are indeed planets and yield mass measurements of these enigmatic worlds that vary between Earth and Neptune in size. Included in the findings are five new rocky planets ranging in size from 10 to 80 percent larger than Earth. Two of the new rocky worlds, dubbed Kepler-99b and Kepler-406b, are both 40 percent larger in size than Earth and have a density similar to lead. The planets orbit their host stars in less than five and three days respectively, making these worlds too hot for life as we know it. A major component of these follow-up observations was Doppler measurements of the planets' host stars. The team measured the reflex wobble of the host star, caused by the gravitational tug on the star exerted by the orbiting planet. That measured wobble reveals the mass of the planet: the higher the mass of the planet, the greater the gravitational tug on the star and hence the greater the wobble. "This marvelous avalanche of information about the mini-Neptune planets is telling us about their core-envelope structure, not unlike a peach with its pit and fruit," said Geoff Marcy, professor of astronomy at the University of California, Berkeley, who led the summary analysis of the high-precision Doppler study. "We now face daunting questions about how these enigmas formed and why our solar system is devoid of the most populous residents in the galaxy." Using one of the world's largest ground-based telescopes at the W. M. Keck Observatory in Hawaii, scientists confirmed 41 of the exoplanets discovered by Kepler and determined the masses of 16. With the mass and diameter in hand, scientists could immediately determine the density of the planets, characterizing them as rocky or gaseous, or mixtures of the two. The density measurements dictate the possible chemical composition of these strange, but ubiquitous planets. The density measurements suggest that the planets smaller than Neptune -- or mini-Neptunes -- have a rocky core but the proportions of hydrogen, helium and hydrogen-rich molecules in the envelope surrounding that core vary dramatically, with some having no envelope at all. The ground-based observation research validates 38 new planets, six of which are non-transiting planets only seen in

Chart of Kepler planet candidates as of January 2014. Image Credit: NASA Ames

the Doppler data. The paper detailing the research is published in the Astrophysical Journal today. A complementary technique used to determine mass, and in turn density of a planet, is by measuring the transit timing variations (TTV). Much like the gravitational force of a planet on its star, neighboring planets can tug on one another, causing one planet to accelerate and another planet to decelerate along its orbit. Ji-Wei Xie of the University of Toronto used TTV to validate 15 pairs of Kepler planets ranging from Earth-sized to a little larger than Neptune. Xie measured masses of the 30 planets, thereby adding to the compendium of planetary characteristics for this new class of planets. The result also was published in the Astrophysical Journal in Dec. 2013. "Kepler's primary objective is to determine the prevalence of planets of varying sizes and orbits. Of particular interest to the search for life is the prevalence of Earth-sized planets in the habitable zone," said Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center in Moffett Field, Calif. "But the question in the back of our minds is: are all planets the size of Earth rocky? Might some be scaled-down

Artist's concept of NASA's Kepler space telescope. Image credit: NASA/JPL-Caltech

versions of icy Neptunes or steamy water worlds? What fraction are recognizable as kin of our rocky, terrestrial globe?" The dynamical mass measurements produced by Doppler and TTV analyses will help to answer these questions. The results hint that a large fraction of planets smaller than 1.5 times the radius of Earth may be comprised of the silicates, iron, nickel and magnesium that are found in the terrestrial planets here in the solar system. Armed with this type of information, scientists will be able to turn the fraction of stars harboring Earth-sizes planets into the fraction of stars harboring bona-fide rocky planets. And that's a step closer to finding a habitable environment beyond the solar system. Ames is responsible for the Kepler mission concept, ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery mission and was funded by the agency's Science Mission Directorate. For more information about the Kepler space telescope, visit: http://www.nasa.gov/kepler . The California Institute of Technology in Pasadena manages JPL for NASA. Images (mentioned), Text, Credits: NASA / J.D. Harrington / JPL / Michele Johnson / Ames Research Center / Michele Johnson. Best regards, Orbiter.ch, Source: Orbiter.ch Space News, Source: Image1-2

Read More........→January 02, 2014

Alien space probes visited Earth many times

Arwen Nicholson and DuncanForgan of the University of Edinburgh (UK) used computer simulations to prove that if representatives of extraterrestrial civilizations were able to travel from one planet to another, they would fly across our entire galaxy in a relatively short period of time and visit our planet. Voyager 1 spacecraft was able to move away from the Earth at a distance of less than one light day in 36 years of its mission. So far, according to scientists, it has not left the solar system. However, according to Nicholson and Forgan, it takes an alien spaceship only ten million years to explore the whole Milky Way. The ship would need to travel at the speed of one-tenth the speed of light, if accelerated due to the gravitational field of stars. During the 1960s, a theory appeared about "smart" space probes capable of replicating themselves. American astronomer Ronald Bracewell believed that mankind should do its best to invent such probes, rather than catch radio signals of artificial origin, as suggested by SETI program. In 1949, John von Neumann developed a mathematical model of the device that was cloning itself. According to current calculations made by Nicholson and Forgan, there are three possible scenarios for such probes to operate. This includes flying with running engines, the use of gravitational acceleration and, finally, "jumping" from star to star. Even the Voyager is capable of "bouncing" from gravitational fields of the solar system. Thus, green aliens are unlikely to be found on Earth, the scientists believe. If aliens ever visited our planet, it was robotic vehicles, rather than living creatures. Famous science fiction writer Arthur C. Clarke gives a description of such visits in his novel "Rendezvous with Rama." In the book, a group of terrestrial astronauts gets inside a giant cylinder stuffed with electronic equipment, approaching the Sun. Nicholson and Forgan believe that alien probes are able to run their own course. They scan the planets of star systems, searching for signs of life there, and create their own copies, which, in turn, search for new stars. To crown it all, it is quite possible that such probes are created by several highly-developed extraterrestrial civilizations. It is also possible that some clone ships may attack other ships as a result of technical failures and destroy them. In any case, such stories can be found in science fiction literature. One can also assume that such ships communicate with each other to carry out their tasks more efficiently - not to explore one and the same object repeatedly, for instance. However, we should not delude ourselves about the contacts of alien robots with earthlings. It is possible that alien probes are equipped with special systems to determine the level of intelligence of the living creatures within range of their activities. Aliens are not interested in establishing communication with intelligent beings. The purpose of robotic devices is the collection of information about the planets, not making contact. Moreover, in all probability, alien space vehicles are programmed to attract as little attention as possible. There is no reliable information, for the time being, to prove that UFOs, or flying saucers, are vessels from other civilizations. One can only build theories, like Nicholson and Forgan do, and wait for brothers in mind, if they do exist, to show themselves to us. Source: Article

Read More........→December 30, 2013

NASA Received An SOS Call From Another Galaxy

NASA detected, intercepted, and decoded a mathematically-based distress signal from a purportedly doomed planetoid outside our own galaxy. The article was written by two journals. NASA simply managed to not get much publicity. At that time the newspapers wrote very little about this issue. When after thirteen years managed to decrypt the message fails to hide from the media The signal was detected in January of 1998 but, however and as it might be expected, it took many years to properly

decode the message. NASA experts claim to have intercepted an intergalactic distress call from an alien civilization that had already peaked and was actually dying when saber-tooth tigers still roamed the earth.  Russian superior officer in ex-Soviet Union’s army Dr. Victor Kulakov told “Universe” that the signal emanated from a point beyond the galaxy nearest to our own, Andromeda, and was sent by beings that had apparently achived a civilization no more advanced than our here on Earth. ” The simple fact that we received and decoded the message proves beyond any doubt that their knowledge and technology were,

at the very best , within our reach ” Dr. Kulakov explained. “And while there are years of study ahead of us, i can say with certainty that the death of their civilization was not the result of some cosmic catastrophe. It was the result of the civilization turning on itself, possibly with devastating nuclear weaponry “.  Dr. Kulakov flatly refused to provide either of the magazines with a transcript of the message, but he did say it began with the plea, “Help us,” and went on to give data pinpointing the exact position of the doomed planet. “There was a quite lucid account of apocalyptic devastation, hellish explosions, widespread death and terminal illnesses ” he said. ” A shower of meteors ? Perhaps. But
what strikes me and this is just a feeling, is an underlying acceptance of guilt. It’s if the senders of the message are acknowledging blame for what happened .” “Whatever it was, they apparently had no means to evacuate the remaining population. Interplanetary space travel was available to them, but only in a very limited level. The message makes it very clear that they were trapped on their world ” said Dr. Kulakov. Source: Article

Read More........→December 17, 2013

Shapley Supercluster

While scanning the sky for the oldest cosmic light, ESA’s Planck satellite has captured snapshots of some of the largest objects populating the Universe today: galaxy clusters and superclusters. Several hundred galaxies and the huge amounts of gas that permeate them are depicted in this view of the core of the Shapley Supercluster, the largest cosmic structure in the local Universe. The supercluster was discovered in the 1930s by American astronomer Harlow Shapley, as a remarkable concentration of galaxies in the Centaurus constellation. Boasting more than 8000 galaxies and with a total mass more than ten million billion times the mass of the Sun, it is the most massive structure within a distance of about a billion light-years from our Milky Way Galaxy. The hot gas pervading galaxy clusters shines brightly in X-rays, but it is also visible at microwave wavelengths, which Planck sees as a distinctive signature in the Cosmic Microwave Background – the afterglow of the Big Bang. Looking for this signature – called the Sunyaev–Zel’dovich effect – Planck has already spotted more than 1000 galaxy clusters, including several superclusters and pairs of interacting clusters. This composite image of the core of the Shapley Supercluster combines the gas detected with Planck at large scales between the members of the supercluster (shown in blue) with that detected in X-rays within the galaxy clusters of Shapley using the Rosat satellite (pink), as well as a view of its rich population of galaxies as observed at visible wavelengths in the Digitised Sky Survey. The largest pink blobs of X-rays identify the two galaxy clusters Abell 3558 on the right and Abell 3562 on the left, as well as a couple of smaller groups between them. The image measures 3.2 x 1.8 square degrees and shows the central portion of the Shapley Supercluster. It was produced by reconstructing the Sunyaev–Zel’dovich effect from the Planck frequency maps, and was first published in a Planck Collaboration paper in March 2013. Image credit: ESA & Planck Collaboration / Rosat/ Digitised Sky Survey. Source: Article

Read More........→October 25, 2013

Colossus In Coma Cluster One Of Largest Structures In Universe, Enormous Arms Of Hot Gas Stretch Half A Million Light Years

Coma Cluster                                                                                                                                                                                                                                                                                           Credit: Chandra

A team of astronomers has discovered enormous arms of hot gas in the Coma cluster of galaxies by using NASA's Chandra X-ray Observatory and ESA's XMM-Newton. These features, which span at least half a million light years, provide insight into how the Coma cluster has grown through mergers of smaller groups and clusters of galaxies to become one of the largest structures in the Universe held together by gravity. A new composite image, with Chandra data in pink and optical data from the Sloan Digital Sky Survey appearing in white and blue, features these spectacular arms (mouse over the image for their location). In this image, the Chandra data have been processed so extra detail can be seen. The X-ray emission is from multimillion-degree gas and the optical data shows galaxies in the Coma Cluster, which contain only about 1/6 the mass in hot gas. Only the brightest X-ray emission is shown here, to emphasize the arms, but the hot gas is present over the entire field of view. Researchers think that these arms were most likely formed when smaller galaxy clusters had their gas stripped away by the head wind created by the motion of the cluster through the hot gas, in much the same way that the headwind created by a roller coaster blows the hats off riders. Coma is an unusual galaxy cluster because it contains not one, but two giant elliptical galaxies near its center. These two giant elliptical galaxies are probably the vestiges from each of the two largest clusters that merged with Coma in the past. The researchers also uncovered other signs of past collisions and mergers in the data. X-Ray Image of Coma Cluster

Credit: Chandra

From their length, and the speed of sound in the hot gas (~4 million km/hr), the newly discovered X-ray arms are estimated to be about 300 million years old, and they appear to have a rather smooth shape. This gives researchers some clues about the conditions of the hot gas in Coma. Most theoretical models expect that mergers between clusters like those in Coma will produce strong turbulence, like ocean water that has been churned by many passing ships. Instead, the smooth shape of these lengthy arms points to a rather calm setting for the hot gas in the Coma cluster, even after many mergers. Large-scale magnetic fields are likely responsible for the small amount of turbulence that is present in Coma. Estimating the amount of turbulence in a galaxy cluster has been a challenging problem for astrophysicists. Researchers have found a range of answers, some of them conflicting, and so observations of other clusters are needed. Two of the arms appear to be connected to a group of galaxies located about two million light years from the center of Coma. One or both of these arms connects to a larger structure seen in the XMM-Newton data, and spans a distance or at least 1.5 million light years. A very thin tail also appears behind one of the galaxies in Coma. This is probably evidence of gas being stripped from a single galaxy, in addition to the groups or clusters that have merged there. These new results on the Coma cluster, which incorporate over six days worth of Chandra observing time, are available online will appear in the September 20, 2013, issue of the journal Science. The first author of the paper is Jeremy Sanders from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany. The co-authors are Andy Fabian from Cambridge University in the UK; Eugene Churazov from the Max Planck Institute for Astrophysics in Garching, Germany; Alexander Schekochihin from University of Oxford in the UK; Aurora Simionescu from the Institute of Space and Astronautical Science in Sagamihara, Japan; Stephen Walker from Cambridge University in the UK and Norbert Werner from Stanford University in Stanford, CA. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra Program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. Source: Nano Patents And Innovations

Read More........→September 24, 2013