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Showing posts from 2015

Astronomers Rename Famous Exoplanets

Source:   By Lee Billings , Scientific American Blog Excerpt: More than 30 worlds have new names drawn from world mythology, literature and history. ...The IAU’s NameExoWorlds contest, which began in July 2014, consisted of public and semi-private rounds of submissions and voting on names for 32 exoplanets and 15 host stars. ...The very first confirmed exoplanetary system, announced in 1992, consists of three rocky worlds orbiting a stellar remnant, a millisecond pulsar ignominiously named PSR 1257+12. Now, the pulsar is suitably called “Lich,” a name for an undead wizard from Greek, Dutch, and Norse folktales. Its three planets bear similarly spooky names drawn from ghostly mythological creatures—“Poltergeist,” “Phobetor” and “Draugr.” Pegasi 51, the first normal star found to host exoplanets, now has a more mellifluous name: “Helvetios,” a Latinized reference to the Helvetians, a tribe of Celts that lived in the Swiss Alps. The name nods to the Swiss astronomers Mi

New Horizons Returns First of the Best Images of Pluto

Source:  NASA Feature Movie: https://www.youtube.com/watch?v=B0xkupKwjfM&feature=youtu.be Latest New Horizons Science Photos - http://pluto.jhuapl.edu/Multimedia/Science-Photos/index.php Images: http://pluto.jhuapl.edu/Multimedia/Science-Photos/pics/Very-Best-View-of-Pluto.png http://pluto.jhuapl.edu/Multimedia/Science-Photos/pics/Very-best-view-of-Pluto-%28mosaic%29.jpg nasa.gov page for New Horizons - https://www.nasa.gov/mission_pages/newhorizons/main/index.html https://www.nasa.gov/feature/new-horizons-returns-first-of-the-best-images-of-pluto

How the moon got its tilt—and Earth got its gold

Source:   By Sid Perkins, Science Excerpt: Miniplanets zooming through our early solar system passed close to our moon and tugged it into the strange, tilted orbit it has today, according to a new study. The findings solve a longstanding mystery and may also explain why Earth’s crust is unexpectedly rich in gold and platinum: When some of these small planets slammed into Earth, they delivered a payload of precious metals. Scientists have long debated the origin of the moon. The prevailing idea, first proposed decades ago, is that a Mars-sized planet collided with Earth, flinging material into space that then coalesced into our only natural satellite. According to current models of that collision, the ring of debris that eventually became the moon should have ended up in a plane tilted no more than 1° from the ecliptic, the plane in which Earth orbits the sun, says Kaveh Pahlevan, a planetary scientist at Université Côte d’Azur in Nice, France. But in fact, the moon’s orbital inclin

Mars to lose its largest moon, but gain a ring.

Source:   By Robert Sanders, UC Berkeley News. For GSS A Changing Cosmos chapter 7. Excerpt: Mars’ largest moon, Phobos, is slowly falling toward the planet, but rather than smash into the surface, it likely will be shredded and the pieces strewn about the planet in a ring like the rings encircling Saturn, Jupiter, Uranus and Neptune  ...in 10-20 million years... that will persist for anywhere from one million to 100 million years, according to two young earth scientists at the University of California, Berkeley. In a paper appearing online this week in Nature Geoscience, UC Berkeley postdoctoral fellow Benjamin Black and graduate student Tushar Mittal estimate the cohesiveness of Phobos and conclude that it is insufficient to resist the tidal forces that will pull it apart when it gets closer to Mars. Just as earth’s moon pulls on our planet in different directions, raising tides in the oceans, for example, so too Mars tugs differently on different parts of Phobos. As

The Dwarf Planet That Came in from the Cold—Maybe

Source:   By Ron Cowen, EoS, Earth & Space Science News, AGU Excerpt: ...The presence of ammonia-rich clay on much of the surface of Ceres suggests that this dwarf planet—the largest object in the asteroid belt—may have formed far out in the solar system, then wandered in.... https://eos.org/articles/the-dwarf-planet-that-came-in-from-the-cold-maybe

Cassini samples an alien ocean

Source:   By Carolyn Gramling, Science. Also NASA, Cassini. 2015-10-30. Cassini samples an alien ocean. For GSS A Changing Cosmos chapter 7. Excerpt: NASA’s Cassini spacecraft has just sent back the first pictures from its deep plunge toward the surface of icy Enceladus, a flyby that took it through one of the moon’s geysers. ...Since Cassini began its flybys of Saturn and its moons in 2005, scientists have learned that beneath the layer of ice is a global ocean about 10 kilometers thick that may harbor life and probably contains hydrothermal vents. They have spotted more than 100 huge geysers of ice particles, water vapor, and organic molecules spewing from fractures in the ice covering Enceladus’s south polar region. These plumes shoot the contents of the moon’s subglacial ocean hundreds of kilometers high, in eruptions that may resemble curtains rather than columns. This week, the spacecraft made its deepest dive into one such plume—just 49 kilometers above the moon’s surface—to

NASA ScienceCasts: Close Encounter with Enceladus

Source:   NASA [Youtube video] NASA's Cassini Spacecraft is about to make a daring plunge through one of the plumes emerging from Saturn's moon Enceladus. https://www.youtube.com/watch?v=nts-bkhoMt4&feature=youtu.be

2015-10-22. NASA Calls for American Industry Ideas on ARM Spacecraft Development.

Source:   NASA Release 15-213 Excerpt: ...NASA's ARRM [Asteroid Redirect Robotic Mission] spacecraft will need to be able to demonstrate support of high power solar electric propulsion, with initial solar array power of approximately 50 kilowatts. The robotics capture system planned aboard the pioneering vehicle will be capable of acquiring a 20 ton (or larger) boulder of up to about 19 feet (six meters) in width from an asteroid's surface and then returning it to an astronaut-accessible orbit near our moon. ...The spacecraft will need to be ready for launch by the end of 2020. ...While at a large asteroid, the spacecraft will demonstrate a "slow-push" planetary defense asteroid deflection technique during the mission. This uses the spacecraft and boulder's combined gravitational pull to attempt to change the course of an asteroid.... http://www.nasa.gov/press-release/nasa-calls-for-american-industry-ideas-on-arm-spacecraft-development

Daily Views of Earth Available on New NASA Website.

Source:   NASA Release 15-199 Excerpt: NASA launched a new website Monday so the world can see images of the full, sunlit side of the Earth every day. The images are taken by a NASA camera one million miles away on the Deep Space Climate Observatory (DSCOVR), a partnership between NASA, the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Air Force. Once a day NASA will post at least a dozen new color images of Earth acquired from 12 to 36 hours earlier by NASA’s Earth Polychromatic Imaging Camera (EPIC). Each daily sequence of images will show the Earth as it rotates, thus revealing the whole globe over the course of a day. The new website also features an archive of EPIC images searchable by date and continent.... http://www.nasa.gov/press-release/daily-views-of-earth-available-on-new-nasa-website

The Pluto system: Initial results from its exploration by New Horizons.

Source:   By S. A. Stern1, F. Bagenal, et al, Science. Abstract: The Pluto system was recently explored by NASA’s New Horizons spacecraft, making closest approach on 14 July 2015. Pluto’s surface displays diverse landforms, terrain ages, albedos, colors, and composition gradients. Evidence is found for a water-ice crust, geologically young surface units, surface ice convection, wind streaks, volatile transport, and glacial flow. Pluto’s atmosphere is highly extended, with trace hydrocarbons, a global haze layer, and a surface pressure near 10 microbars. Pluto’s diverse surface geology and long-term activity raise fundamental questions about how small planets remain active many billions of years after formation. Pluto’s large moon Charon displays tectonics and evidence for a heterogeneous crustal composition; its north pole displays puzzling dark terrain. Small satellites Hydra and Nix have higher albedos than expected....  For latest images from New Horizons Mission to Pluto, see 

Enceladus’s subsurface ocean wraps the moon

Source:  Steven K. Blau, Physics Today Excerpt: 2015-10-12. Enceladus’s subsurface ocean wraps the moon. By Steven K. Blau, Physics Today. For GSS A Changing Cosmos chapter 7. Excerpt: The satellite’s response to torque applied by Saturn shows that its icy surface and silicate core are not attached. A decade ago the Cassini orbiter spotted gas and ice spewing from the south polar region of Saturn’s moon Enceladus. Subsequent investigations revealed that the ice is salty, a result indicating that the ice originated from a liquid ocean between Enceladus’s frozen surface and its silicate core. Now Peter Thomas (Cornell University) and his colleagues have analyzed more than seven years of Cassini surface observations and shown that the ocean is not localized at the polar region of Enceladus; rather, it is global....  URL 0 http://scitation.aip.org/content/aip/magazine/physicstoday/news/10.1063/PT.5.7210

Fortifying Computer Chips for Space Travel

Source:   Lawrence Berkeley National Laboratory Excerpts: Berkeley Lab's particle accelerator blasts microprocessors with high-energy beams to toughen them up.  Space is cold, dark, and lonely. Deadly, too, if any one of a million things goes wrong on your spaceship. It's certainly no place for a computer chip to fail, which can happen due to the abundance of radiation bombarding a craft. Worse, ever-shrinking components on microprocessors make computers more prone to damage from high-energy radiation like protons from the sun or cosmic rays from beyond our galaxy. It's a good thing, then, that engineers know how to make a spaceship's microprocessors more robust. To start, they hit them with high-energy ions from particle accelerators here on Earth. ...One of the most long-lived and active space-chip testing programs is at the U.S. Department of Energy's Lawrence Berkeley National Lab (Berkeley Lab). ...Since 1979, most American satellites have had one or more e

Saturn’s moon has a fluffy heart

Source:   By Nola Taylor Redd, Science Excerpt: Saturn's moon, Enceladus, may not have a heart of stone—at least, not completely. A new model suggests the satellite has a rubble-filled pile of boulders and ice at its core, rather than a more conventional solid stone center. This “fluffy core” could help solve the mystery of the moon’s underground ocean. A watery layer beneath Enceladus’s crust has long been suspected to exist because of the constant eruption of geysers at its southern pole. But scientists have said that any such ocean should have frozen over the lifetime of the Saturn system. Tidal heating that warms the insides of moons and planets in orbit would simply not be enough to keep this ocean in a liquid state if Enceladus had a solid core. ...A heart of rubble would flex more easily with the tidal pull of Saturn, emitting enough heat to maintain a liquid layer.... http://news.sciencemag.org/space/2015/08/saturn-s-moon-has-fluffy-heart

NASA's Spitzer Confirms Closest Rocky Exoplanet

Source:   NASA Release 15-160 Excerpt: Using NASA's Spitzer Space Telescope, astronomers have confirmed the discovery of the nearest rocky planet outside our solar system, larger than Earth and a potential gold mine of science data. Dubbed HD 219134b, this exoplanet, which orbits too close to its star to sustain life, is a mere 21 light-years away. While the planet itself can't be seen directly, even by telescopes, the star it orbits is visible to the naked eye in dark skies in the Cassiopeia constellation, near the North Star. HD 219134b is also the closest exoplanet to Earth to be detected transiting, or crossing in front of, its star and, therefore, perfect for extensive research. ..."Most of the known planets are hundreds of light-years away. This one is practically a next-door neighbor," said astronomer and study co-author Lars A. Buchhave of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. For reference, the closest known planet is

NASA’s New Horizons Team Finds Haze, Flowing Ice on Pluto

Source:   NASA Release 15-158 Excerpt: Flowing ice and a surprising extended haze are among the newest discoveries from NASA’s New Horizons mission, which reveal distant Pluto to be an icy world of wonders. “We knew that a mission to Pluto would bring some surprises, and now -- 10 days after closest approach -- we can say that our expectation has been more than surpassed,” said John Grunsfeld, NASA’s associate administrator for the Science Mission Directorate. “With flowing ices, exotic surface chemistry, mountain ranges, and vast haze, Pluto is showing a diversity of planetary geology that is truly thrilling." Just seven hours after closest approach, New Horizons aimed its Long Range Reconnaissance Imager (LORRI) back at Pluto, capturing sunlight streaming through the atmosphere and revealing hazes as high as 80 miles (130 kilometers) above Pluto’s surface. A preliminary analysis of the image shows two distinct layers of haze -- one about 50 miles (80 kilometers)

NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

Source:  NASA Kepler Mission In a press conference this morning (2015 July 23), NASA's Kepler team announced discovery of planet Kepler-452b which has the closest match of planet characteristics to Earth: 60% larger than Earth, orbiting a Sun-like star in a 385 day orbit period, that puts it in the star's habitable zone. [Kepler confirmed planet count is now 1030.] The team also announced a new Kepler planet catalog with 4696 planet candidates (521 more than previous catalog). http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=393

Pluto's Moons Nix and Hydra Show Their Faces

Source:   By  JoAnna Wendel ,  EoS Earth & Space Science News Excerpt:  Pluto’s moons Hydra and Nix appear in unprecedented sharpness in images released today from NASA’s New Horizons mission. For the first time, scientists are also able to estimate the sizes of these tiny natural satellites: Nix (left) at 26 miles (42 kilometers) by 22 miles (36 kilometers) and Hydra (right), 34 miles (55 kilometers) by 25 miles (40 kilometers). Nix’s new portrait, imaged in enhanced colors, shows a reddish patch reminiscent of a bull’s-eye. In a press release , scientists said that they suspect the region could be an impact crater on the jelly bean-shaped moon but are awaiting additional data from the spacecraft to better understand what they’ve observed. https://eos.org/articles/plutos-moons-nix-and-hydra-show-their-faces

NASA Captures "EPIC" Earth Image

Source:   NASA Deep Space Climate Observatory satellite Excerpt: A NASA camera on the Deep Space Climate Observatory [DSCOVR] satellite has returned its first view of the entire sunlit side of Earth from one million miles away...taken by NASA’s Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope. [This...is the first complete picture of our planet since 1972 (those in the interim have actually been composites). ...DSCOVR [is] a joint mission between NASA, the National Oceanic and Atmospheric Administration, and the U.S. Air Force.... http://www.nasa.gov/image-feature/nasa-captures-epic-earth-image

Potential geysers spotted on Pluto

Source:   Science online Excerpt: Today, NASA’s New Horizons team unveiled the latest trove of geological goodies in close-up pictures of the surface of Pluto: hummocky hills that rise up above smooth plains of ice, patches of ice pocked by eroded pits, and troughs that form the boundaries of mysterious polygonal structures. Most tantalizing of all, the team has spotted streaks of material that may have blown downwind from dark spots. Although the team is not yet ready to declare that these spots are geysers shooting plumes above Pluto, scientists say the spots and streaks resemble actively spewing geysers on Neptune’s moon Triton that were discovered in 1989. See also NASA Release 15-152, July 15, 2015: From Mountains to Moons: Multiple Discoveries from NASA’s New Horizons Pluto Mission - http://www.nasa.gov/press-release/from-mountains-to-moons-multiple-discoveries-from-nasa-s-new-horizons-pluto-mission 0 and  NASA Release 15-154, July 17, 2015: NASA’s New Horizons Disc

NASA's Three-Billion-Mile Journey to Pluto Reaches Historic Encounter

Source:   NASA Release 15-149 NASA’s New Horizons spacecraft is at Pluto. After a decade-long journey through our solar system, New Horizons made its closest approach to Pluto Tuesday, about 7,750 miles above the surface -- roughly the same distance from New York to Mumbai, India – making it the first-ever space mission to explore a world so far from Earth. [photo taken on July 13, 2015 when the spacecraft was 476,000 miles (768,000 kilometers) from the surface. ...the last and most detailed image sent to Earth before the spacecraft’s closest approach to Pluto on July 14.] http://www.nasa.gov/press-release/nasas-three-billion-mile-journey-to-pluto-reaches-historic-encounter

How Did the Moon Get Its Shape?

Source:   By Catherine Minnehan , EOS—publication of AGU Excerpts: Scientists find a solution to a 200-year-old problem: syncing the prominent bulges on the Moon with our natural satellite's origins. Scientists have known for hundreds of years that the Moon’s rotational and tidal bulges are much larger than expected. The deformation is thought to be a remnant from when the Moon orbited much closer to Earth than it does today. The problem is, the bulges we see require an unusual eccentric orbit—one that scientists do not think the Moon ever had. Keane and Matsuyama solved this problem by discovering a new component to the Moon’s global figure. The Moon is not perfectly spherical because strong forces pull it in different directions. There are two main forces: bulging at the equator due to lunar rotation and bulging on the nearside and farside due to tidal forces between the Earth and the Moon. The observed lunar deformation is much larger than scientists would exp

Exoplanets: Worlds Without End

Source:   Scientific American eBook description: Section 1, “Exo-Search,” sets the stage and outlines how astronomers are looking for new worlds: the various techniques, how they’ve improved to date and plans for upcoming missions. Sections 2 through 5 analyze the discoveries, often both controversial and strange. Section 3 focuses on the race to find other Earth-like planets. With excitement at an all-time high, author Ron Cowen cautions against publishing too quickly out of optimism. In “Noisy Stars May Create Phantom Planets,” Cowen describes how stellar activity can mimic the signs of tiny exoplanets. Section 4 takes on the real oddballs. They may be remnants of gas giants whose atmospheres were stripped away, as in the piece "The Bones of Giants," or have alien chemistries. Some trace their course around white dwarfs, the results of a second generation of planets forming around old stars. Section 5 asks if there’s life out there. In "Anybody Home?&q

NASA’s Hubble Finds Pluto’s Moons Tumbling in Absolute Chaos

Source:   NASA Release 15-111. Excerpt: If you lived on one of Pluto’s moons, you might have a hard time determining when, or from which direction, the sun will rise each day. Comprehensive analysis of data from NASA’s Hubble Space Telescope shows that two of Pluto’s moons, Nix and Hydra, wobble unpredictably. “Hubble has provided a new view of Pluto and its moons revealing a cosmic dance with a chaotic rhythm,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate in Washington. ...The moons wobble because they’re embedded in a gravitational field that shifts constantly. This shift is created by the double planet system of Pluto and Charon as they whirl about each other. Pluto and Charon are called a double planet because they share a common center of gravity located in the space between the bodies. Their variable gravitational field sends the smaller moons tumbling erratically. The effect is strengthened by the football-like, rather than spherical, sh

Halley's Eclipse: a coup for Newtonian prediction and the selling of science.

Source:   By Rebekah Higgit, The Guardian. Excerpt: 300 years ago, on the 3rd of May 1715, a rare solar eclipse occurred over England. It was an opportunity too good to miss for those promoting new astronomical theories – and their own careers. In 1715, 300 years ago today, a total solar eclipse was visible across a broad band of England. It was the first to be predicted on the basis of the Newtonian theory of universal gravitation, its path mapped clearly and advertised widely in advance. Visible in locations such as London and Cambridge, both astronomical experts and the public were able to see the phenomena and be impressed by the predictive power of the new astronomy. Wikipedia will tell you that this is known as Halley’s Eclipse, after Edmond Halley, who produced accurate predictions of its timing and an easily-read map of the eclipse’s path. Halley did not live to see the confirmation of his predictions of a returning comet – a 1759 triumph for the Newtonian system – but he wa

Alien Supercivilizations Absent from 100,000 Nearby Galaxies

Source: By Lee Billings, Scientific American           Excerpt: ...search for extraterrestrial intelligence (SETI) ...has yet to detect any signals that withstand close scrutiny. Even if brimming with life, to us, the galaxy seems to be a very quiet, rather lonely place. Now, new results suggest this loneliness may extend out into the universe far beyond our galaxy.... After examining some 100,000 nearby large galaxies a team of researchers lead by The Pennsylvania State University astronomer Jason Wright has concluded that none of them contain any obvious signs of highly advanced technological civilizations. ...they looked for the thermodynamic consequences of galactic-scale colonization, based on an idea put forth in 1960 by the physicist Freeman Dyson.  ...the team searched for type 3 civilizations in an all-sky catalogue from NASA’s Wide-field Infrared Survey Explorer (WISE). They looked for objects that were optically dim but bright in the mid-infrared—the expected signature o

NASA Spacecraft Achieves Unprecedented Success Studying Mercury

Source:   NASA Excerpt: After extraordinary science findings and technological innovations,  ...NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft launched in 2004 to study Mercury will impact the planet’s surface, most likely on April 30, after it runs out of propellant. ...Although Mercury is one of Earth’s nearest planetary neighbors, little was known about the planet prior to the MESSENGER mission. “For the first time in history we now have real knowledge about the planet Mercury that shows it to be a fascinating world as part of our diverse solar system,” said John Grunsfeld, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington.  ...One key science finding in 2012 provided compelling support for the hypothesis that Mercury harbors abundant frozen water and other volatile materials in its permanently shadowed polar craters. Data indicated the ice in Mercury's polar regions, if spread over an

Huge ocean confirmed underneath solar system’s largest moon

Source:  By Eric Hand, Science 2015-03-12. Excerpt: The solar system’s largest moon, Ganymede, in orbit around Jupiter, harbors an underground ocean containing more water than all the oceans on Earth. ...new observations by the Hubble Space Telescope, published online today in the Journal of Geophysical Research: Space Physics, remove any remaining doubt. Ganymede now joins Jupiter’s Europa and two moons of Saturn, Titan and Enceladus, as moons with subsurface oceans—and good places to look for life. ...The Hubble study suggests that the ocean can be no deeper than 330 kilometers below the surface.... http://news.sciencemag.org/space/2015/03/huge-ocean-confirmed-underneath-solar-system-s-largest-moon

NASA Spacecraft Becomes First to Orbit a Dwarf Planet

Source:   NASA RELEASE 15-034. Excerpt: NASA's Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet. The spacecraft was approximately 38,000 miles (61,000 kilometers) from Ceres when it was captured by the dwarf planet’s gravity at about 4:39 a.m. PST (7:39 a.m. EST) Friday. ..."Since its discovery in 1801, Ceres was known as a planet, then an asteroid and later a dwarf planet," said Marc Rayman, Dawn chief engineer and mission director at JPL. "Now, after a journey of 3.1 billion miles (4.9 billion kilometers) and 7.5 years, Dawn calls Ceres, home.".... See also New York Times photos . http://www.nasa.gov/press/2015/march/nasa-spacecraft-becomes-first-to-orbit-a-dwarf-planet/#.VPy7UmZIfZE

NASA Research Suggests Mars Once Had More Water than Earth’s Arctic Ocean

Source:   NASA RELEASE 15-032. Excerpt: NASA scientists have determined that a primitive ocean on Mars held more water than Earth's Arctic Ocean and that the Red Planet has lost 87 percent of that water to space.... Scientists have been searching for answers to why this vast water supply left the surface. Details of the observations and computations appear in Thursday’s edition of Science magazine.... “With Mars losing that much water, the planet was very likely wet for a longer period of time than was previously thought, suggesting it might have been habitable for longer,” said Michael Mumma, a senior scientist at Goddard and the second author on the paper. See also New York Times article Ancient Mars Had an Ocean, Scientists Say . http://www.nasa.gov/press/2015/march/nasa-research-suggests-mars-once-had-more-water-than-earth-s-arctic-ocean/

Ten new Rosetta images that reveal comet 67P in all its glory.

Source:   By Eric Hand, Science Excerpt:  In August 2014, the European Space Agency’s Rosetta spacecraft arrived at comet 67P/Churyumov-Gerasimenko. Once in orbit, it swooped as low as 10 kilometers to get unprecedented data from the comet (and to drop off its short-lived Philae lander). Today, Science is publishing a suite of new papers detailing some of the mission’s first findings, .... Active pits... Erosion from cliff faces... boulders on unstable slopes... jetting...fissure...comet vomit...windlike features....  http://news.sciencemag.org/space/2015/01/ten-new-rosetta-images-reveal-comet-67p-all-its-glory *. http://news.sciencemag.org/space/2015/01/ten-new-rosetta-images-reveal-comet-67p-all-its-glory

Asteroid to Fly By Earth Safely on January 26

Source:   NASA Jet Propulsion Laboratory Excerpt:  An asteroid, designated 2004 BL86, will safely pass about three times the distance of Earth to the moon on January 26. ...astronomers estimate that the asteroid is about a third of a mile (0.5 kilometers) in size. The flyby of 2004 BL86 will be the closest by any known space rock this large until asteroid 1999 AN10 flies past Earth in 2027. At the time of its closest approach on January 26, the asteroid will be approximately 745,000 miles (1.2 million kilometers) from Earth. "Monday, January 26 will be the closest asteroid 2004 BL86 will get to Earth for at least the next 200 years," said Don Yeomans, who is retiring as manager of NASA's Near Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California, after 16 years in the position. "And while it poses no threat to Earth for the foreseeable future, it's a relatively close approach by a relatively large ast

So Many Earth-Like Planets, So Few Telescopes

Source:   By Dennis Overbye, The New York Times. Front page story. Excerpts: Astronomers announced on Tuesday that they had found eight new planets orbiting their stars at distances compatible with liquid water, bringing the total number of potentially habitable planets in the just-right “Goldilocks” zone to a dozen or two, depending on how the habitable zone of a star is defined. NASA’s Kepler spacecraft, now in its fifth year of seeking out the shadows of planets circling other stars, has spotted hundreds, and more and more of these other worlds look a lot like Earth — rocky balls only slightly larger than our own home, that with the right doses of starlight and water could turn out to be veritable gardens of microbial Eden. ...Reviewing the history of exoplanets, Debra Fischer, a Yale astronomer, recalled that the first discovery of a planet orbiting another normal star, a Jupiter-like giant, was 20 years ago. Before that, she said, astronomers worried that “maybe the ‘Star Trek