Tagged: Basic Research Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 8:14 pm on July 30, 2015 Permalink | Reply
    Tags: , Basic Research, ,   

    From phys.org: “Earth’s magnetic shield is much older than previously thought” 

    physdotorg
    phys.org

    July 30, 2015
    U Rochester

    1
    An artist’s depiction of Earth’s magnetic field deflecting high-energy protons from the sun four billion years ago. Note: The relative sizes of the Earth and Sun, as well as the distances between the two bodies, are not drawn to scale. Credit: Graphic by Michael Osadciw/University of Rochester.

    Since 2010, the best estimate of the age of Earth’s magnetic field has been 3.45 billion years. But now a researcher responsible for that finding has new data showing the magnetic field is far older.

    John Tarduno, a geophysicist at the University of Rochester and a leading expert on Earth’s magnetic field, and his team of researchers say they believe the Earth’s magnetic field is at least four billion years old.

    “A strong magnetic field provides a shield for the atmosphere,” said Tarduno, “This is important for the preservation of habitable conditions on Earth.”

    The findings by Tarduno and his team have been published in the latest issue of the journal Science.

    Earth’s magnetic field protects the atmosphere from solar winds—streams of charged particles shooting from the Sun. The magnetic field helps prevent the solar winds from stripping away the atmosphere and water, which make life on the planet possible.

    Earth’s magnetic field is generated in its liquid iron core, and this “geodynamo” requires a regular release of heat from the planet to operate. Today, that heat release is aided by plate tectonics, which efficiently transfers heat from the deep interior of the planet to the surface.

    2
    The tectonic plates of the world were mapped in the second half of the 20th century.

    But, according to Tarduno, the time of origin of plate tectonics is hotly debated, with some scientists arguing that Earth lacked a magnetic field during its youth.

    Given the importance of the magnetic field, scientists have been trying to determine when it first arose, which could, in turn, provide clues as to when plate tectonics got started and how the planet was able to remain habitable.

    Fortunately for scientists, there are minerals—such as magnetite—that lock in the magnetic field record at the time the minerals cooled from their molten state. The oldest available minerals can tell scientists the direction and the intensity of the field at the earliest periods of Earth’s history. In order to get reliable measurements, it’s crucial that the minerals obtained by scientists are pristine and never reached a sufficient heat level that would have allowed the old magnetic information within the minerals to reset to the magnetic field of the later time.

    The directional information is stored in microscopic grains inside magnetite- a naturally occurring magnetic iron oxide. Within the smallest magnetite grains are regions that have their own individual magnetizations and work like a tape recorder. Just as in magnetic tape, information is recorded at a specific time and remains stored unless it is replaced under specific conditions.

    Tarduno’s new results are based on the record of magnetic field strength fixed within magnetite found within zircon crystals collected from the Jack Hills of Western Australia.

    3
    Jack Hills satellite image

    The zircons were formed over more than a billion years and have come to rest in an ancient sedimentary deposit. By sampling zircons of different age, the history of the magnetic field can be determined.

    The ancient zircons are tiny—about two-tenths of a millimeter—and measuring their magnetization is a technological challenge. Tarduno and his team used a unique superconducting quantum interference device, or SQUID magnetometer, at the University of Rochester that provides a sensitivity ten times greater than comparable instruments.

    But in order for today’s magnetic intensity readings of the magnetite to reveal the actual conditions of that era, the researchers needed to make sure the magnetite within the zircon remained pristine from the time of formation.

    Of particular concern was a period some 2.6 billion years ago during which temperatures in the rocks of the Jack Hills reached 475?C. Under those conditions, it was possible that the magnetic information recorded in the zircons would have been erased and replaced by a new, younger recording of Earth’s magnetic field.

    “We know the zircons have not been moved relative to each other from the time they were deposited,” said Tarduno. “As a result, if the magnetic information in the zircons had been erased and re-recorded, the magnetic directions would have all been identical.”

    Instead, Tarduno found that the minerals revealed varying magnetic directions, convincing him that the intensity measurements recorded in the samples were indeed as old as four billion years.

    The intensity measurements reveal a great deal about the presence of a geodynamo at the Earth’s core. Tarduno explains that solar winds could interact with the Earth’s atmosphere to create a small magnetic field, even in the absence of a core dynamo. Under those circumstances, he calculates that the maximum strength of a magnetic field would be 0.6 uT (micro-Teslas). The values measured by Tarduno and his team were much greater than 0.6 ?T, indicating the presence of a geodynamo at the core of the planet, as well as suggesting the existence of the plate tectonics needed to release the built-up heat.

    “There has been no consensus among scientists on when plate tectonics began,” said Tarduno. “Our measurements, however, support some previous geochemical measurements on ancient zircons that suggest an age of 4.4 billion years.”

    The magnetic field was of special importance in that eon because solar winds were about 100 times stronger than today. In the absence of a magnetic field, Tarduno says the protons that make up the solar winds would have ionized and stripped light elements from the atmosphere, which, among other things, resulted in the loss of water.

    Scientists believe that Mars had an active geodynamo when that planet was formed, but that it died off after four billion years. As a result, Tarduno says, the Red Planet had no magnetic field to protect the atmosphere, which may explain why its atmosphere is so thin.

    “It may also be a major reason why Mars was unable to sustain life,” said Tarduno.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 4:06 pm on July 30, 2015 Permalink | Reply
    Tags: , Basic Research, ,   

    From JPL: “NASA’s Spitzer Confirms Closest Rocky Exoplanet” 

    JPL

    July 30, 2015
    Felicia Chou NASA Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov

    Whitney Clavin
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-4673
    whitney.b.clavin@jpl.nasa.gov

    1
    This artist’s conception shows the silhouette of a rocky planet, dubbed HD 219134b, as it passes in front of its star. At 21 light-years away, the planet is the closest outside of our solar system that can be seen crossing, or transiting, its star — a bonus for astronomers because transiting planets make ideal specimens for detailed studies of their atmospheres. It was discovered using the HARPS-North instrument on the Italian 3.6-meter National Galileo Telescope in the Canary Islands, and NASA’s Spitzer Space Telescope.

    The planet, which is about 1.6 times the size of Earth, is also the nearest confirmed rocky planet outside our solar system. It orbits a star that is cooler and smaller than our sun, whipping closely around it in a mere three days. The proximity of the planet to the star means that it would be scorching hot and not habitable.

    Transiting planets are ideal targets for astronomers wanting to know more about planetary compositions and atmospheres. As a planet passes in front of its star, it causes the starlight to dim, and telescopes can measure this effect. If molecules are present in the planet’s atmosphere, they can absorb certain wavelengths of light, leaving imprints in the starlight. This type of technique will be used in the future to investigate potentially habitable planets and search for signs of life.

    2
    This sky map shows the location of the star HD 219134 (circle), host to the nearest confirmed rocky planet found to date outside of our solar system. The star lies just off the “W” shape of the constellation Cassiopeia and can be seen with the naked eye in dark skies. It actually has multiple planets, none of which are habitable.

    3
    This artist’s rendition shows one possible appearance for the planet HD 219134b, the nearest confirmed rocky exoplanet found to date outside our solar system. The planet is 1.6 times the size of Earth, and whips around its star in just three days. Scientists predict that the scorching-hot planet — known to be rocky through measurements of its mass and size — would have a rocky, partially molten surface with geological activity, including possibly volcanoes.

    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.

    NASA Spitzer Telescope
    Spitzer

    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.

    “Transiting exoplanets are worth their weight in gold because they can be extensively characterized,” said Michael Werner, the project scientist for the Spitzer mission at NASA’s Jet Propulsion Laboratory in Pasadena, California. “This exoplanet will be one of the most studied for decades to come.”

    The planet, initially discovered using the HARPS-North instrument on the Italian 3.6-meter Galileo National Telescope in the Canary Islands, is the subject of a study accepted for publication in the journal Astronomy & Astrophysics

    Telescoipio Nazionale Galileo.
    Galileo National Telescope

    Telescopio Nazionale Galileo - Harps North
    HARPS-North instrument

    Study lead author Ati Motalebi of the Geneva Observatory in Switzerland said she believes the planet is the ideal target for NASA’s James Webb Space Telescope in 2018.

    NASA James Webb Telescope
    Webb

    “Webb and future large, ground-based observatories are sure to point at it and examine it in detail,” Motalebi said.

    Only a small fraction of exoplanets can be detected transiting their stars due to their relative orientation to Earth. When the orientation is just right, the planet’s orbit places it between its star and Earth, dimming the detectable light of its star. It’s this dimming of the star that is actually captured by observatories such as Spitzer and can reveal not only the size of the planet but also clues about its composition.

    “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 GJ674b at 14.8 light-years away; its composition is unknown.

    HD 219134b was first sighted by the HARPS-North instrument and a method called the radial velocity technique, in which a planet’s mass and orbit can be measured by the tug it exerts on its host star. The planet was determined to have a mass 4.5 times that of Earth, and a speedy three-day orbit around its star.

    Spitzer followed up on the finding, discovering the planet transits its star. Infrared measurements from Spitzer revealed the planet’s size, about 1.6 times that of Earth. Combining the size and mass gives it a density of 3.5 ounces per cubic inch (six grams per cubic centimeter) — confirming HD 219134b is a rocky planet.

    Now that astronomers know HD 219134b transits its star, scientists will be scrambling to observe it from the ground and space. The goal is to tease chemical information out of the dimming starlight as the planet passes before it. If the planet has an atmosphere, chemicals in it can imprint patterns in the observed starlight.

    Rocky planets such as this one, with bigger-than-Earth proportions, belong to a growing class of planets termed super-Earths.

    “Thanks to NASA’s Kepler mission, we know super-Earths are ubiquitous in our galaxy, but we still know very little about them,” said co-author Michael Gillon of the University of Liege in Belgium, lead scientist for the Spitzer detection of the transit.

    NASA Kepler Telescope
    Kepler

    “Now we have a local specimen to study in greater detail. It can be considered a kind of Rosetta Stone for the study of super-Earths.”

    Further observations with HARPS-North also revealed three more planets in the same star system, farther than HD 219134b. Two are relatively small and not too far from the star. Small, tightly packed multi-planet systems are completely different from our own solar system, but, like super-Earths, are being found in increasing numbers.

    JPL manages the Spitzer mission for NASA’s Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Co. in Littleton, Colorado. Data are archived at the Infrared Science Archive, housed at Caltech’s Infrared Processing and Analysis Center.

    For more information about NASA’s Spitzer Space Telescope, visit:

    http://www.nasa.gov/spitzer

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

    Caltech Logo
    jpl

     
  • richardmitnick 3:42 pm on July 30, 2015 Permalink | Reply
    Tags: , Basic Research, ,   

    From Keck: “Telescopes Team Up to Find Distant Uranus-Sized Planet Through Microlensing” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    July 30, 2015
    SCIENCE CONTACT
    Dave Bennett
    University of Notre Dame
    bennett@nd.edu
    574-315-6621

    Jean-Phillipe Beaulieu
    Institut d’Astrophysique de Paris
    Beaulieu@iap.fr
    +33 6 03 98 73 11

    MEDIA CONTACT
    Steve Jefferson
    W. M. Keck Observatory
    sjefferson@keck.hawaii.edu
    808-881-3827

    1
    Credit: NASA, ESA, and A. Feild (STScI)

    The W. M. Keck Observatory in Hawaii and NASA’s Hubble Space Telescope have made independent confirmations of an exoplanet orbiting far from its central star.

    NASA Hubble Telescope
    NASA/ESA Hubble

    The planet was discovered through a technique called gravitational microlensing. This finding opens a new piece of discovery space in the extrasolar planet hunt: to uncover planets as far from their central stars as Jupiter and Saturn are from our sun. The Hubble and Keck Observatory results will appear in two papers in the July 30 edition of The Astrophysical Journal.

    The large majority of exoplanets cataloged so far are very close to their host stars because several current planet-hunting techniques favor finding planets in short-period orbits. But this is not the case with the microlensing technique, which can find more distant and colder planets in long-period orbits that other methods cannot detect.

    Microlensing occurs when a foreground star amplifies the light of a background star that momentarily aligns with it. If the foreground star has planets, then the planets may also amplify the light of the background star, but for a much shorter period of time than their host star. The exact timing and amount of light amplification can reveal clues to the nature of the foreground star and its accompanying planets.

    “Microlensing is currently the only method to detect the planets close to their birth place,” said team member, Jean-Philippe Beaulieu, Institut d’Astrophysique de Paris. “Indeed, planets are being mostly formed at a certain distance from the central star where it is cold enough for volatile compounds to condense into solid ice grains. These grains will then aggregate and will ultimately evolve into planets.”

    The system, cataloged as OGLE-2005-BLG-169, was discovered in 2005 by the Optical Gravitational Lensing Experiment (OGLE), the Microlensing Follow-Up Network (MicroFUN), and members of the Microlensing Observations in Astrophysics (MOA) collaborations—groups that search for extrasolar planets through gravitational microlensing.

    Without conclusively identifying and characterizing the foreground star, however, astronomers have had a difficult time determining the properties of the accompanying planet. Using Hubble and the Keck Observatory, two teams of astronomers have now found that the system consists of a Uranus-sized planet orbiting about 370 million miles from its parent star, slightly less than the distance between Jupiter and the sun. The host star, however, is about 70 percent as massive as our sun.

    “These chance alignments are rare, occurring only about once every 1 million years for a given planet, so it was thought that a very long wait would be required before the planetary microlensing signal could be confirmed,” said David Bennett, the lead of the team that analyzed the Hubble data. “Fortunately, the planetary signal predicts how fast the apparent positions of the background star and planetary host star will separate, and our observations have confirmed this prediction. The Hubble and Keck Observatory data, therefore, provide the first confirmation of a planetary microlensing signal.”

    In fact, microlensing is such a powerful tool that it can uncover planets whose host stars cannot be seen by most telescopes. “It is remarkable that we can detect planets orbiting unseen stars, but we’d really like to know something about the stars that these planets orbit,” explained Virginie Batista, leader of the Keck Observatory analysis. “The Keck and Hubble telescopes allow us to detect these faint planetary host stars and determine their properties.”

    Planets are small and faint compared to their host stars; only a few have been observed directly outside our solar system. Astronomers often rely on two indirect techniques to hunt for extrasolar planets. The first method detects planets by the subtle gravitational tug they give to their host stars. In another method, astronomers watch for small dips in the amount of light from a star as a planet passes in front of it.

    Both of these techniques work best when the planets are either extremely massive or when they orbit very close to their parent stars. In these cases, astronomers can reliably determine their short orbital periods, ranging from hours to days to a couple years.

    But to fully understand the architecture of distant planetary systems, astronomers must map the entire distribution of planets around a star. Astronomers, therefore, need to look farther away from the star—from about the distance of Jupiter is from our sun, and beyond.

    “It’s important to understand how these systems compare with our solar system,” said team member Jay Anderson of the Space Telescope Science Institute in Baltimore, MD. “So we need a complete census of planets in these systems. Gravitational microlensing is critical in helping astronomers gain insights into planetary formation theories.”

    The planet in the OGLE system is probably an example of a “failed-Jupiter” planet, an object that begins to form a Jupiter-like core of rock and ice weighing around 10 Earth masses, but it doesn’t grow fast enough to accrete a significant mass of hydrogen and helium. So it ends up with a mass more than 20 times smaller than that of Jupiter. “Failed-Jupiter planets, like OGLE-2005-BLG-169Lb, are predicted to be more common than Jupiters, especially around stars less massive than the sun, according to the preferred theory of planet formation. So this type of planet is thought to be quite common,” Bennett said.

    Microlensing takes advantage of the random motion of stars, which are generally too small to be noticed without precise measurements. If one star, however, passes nearly precisely in front of a farther background star, the gravity of the foreground star acts like a giant lens, magnifying the light from the background star.

    A planetary companion around the foreground star can produce a variation in the brightening of the background star. This brightening fluctuation can reveal the planet, which can be too faint, in some cases, to be seen by telescopes. The duration of an entire microlensing event is several months, while the variation in brightening due to a planet lasts a few hours to a couple of days.

    The initial microlensing data of OGLE-2005-BLG-169 had indicated a combined system of foreground and background stars plus a planet. But due to the blurring effects of our atmosphere, a number of unrelated stars are also blended with the foreground and background stars in the very crowded star field in the direction of our galaxy’s center.

    “The Hubble Space telescope and KECK2 are unique facilities providing complementary high angular resolution observations to characterise these cold planets orbiting very distant stars,” Beaulieu said.

    The sharp Hubble and Keck Observatory images allowed the research teams to separate out the background source star from its neighbors in the very crowded star field in the direction of our galaxy’s center. Although the Hubble images were taken 6.5 years after the lensing event, the source and lens star were still so close together on the sky that their images merged into what looked like an elongated stellar image.

    Astronomers can measure the brightness of both the source and planetary host stars from the elongated image. When combined with the information from the microlensing light curve, the lens brightness reveals the masses and orbital separation of the planet and its host star, as well as the distance of the planetary system from Earth. The foreground and background stars were observed in several different colors with Hubble’s Wide Field Camera 3 (WFC3), allowing independent confirmations of the mass and distance determinations.

    NASA Hubble WFC3
    WFC3

    The observations, taken with the Near Infrared Camera 2 (NIRC2) on the Keck 2 telescope more than eight years after the microlensing event, provided a precise measurement of the foreground and background stars’ relative motion.

    Keck NIRC2
    NIRC2

    “It is the first time we were able to completely resolve the source star and the lensing star after a microlensing event. This enabled us to discriminate between two models that fit the data of the microlensing light curve,” Batista said.

    The Hubble and Keck Observatory data are providing proof of concept for the primary method of exoplanet detection that will be used by NASA’s planned, space-based Wide-Field Infrared Survey Telescope (WFIRST), which will allow astronomers to determine the masses of planets found with microlensing.

    NASA WFIRST telescope
    WFIRST

    WFIRST will have Hubble’s sharpness to search for exoplanets using the microlensing technique. The telescope will be able to observe foreground, planetary host stars approaching the background source stars prior to the microlensing events, and receding from the background source stars after the microlensing events.

    “WFIRST will make measurements like we have made for OGLE-2005-BLG-169 for virtually all the planetary microlensing events it observes. We’ll know the masses and distances for the thousands of planets discovered by WFIRST,” Bennett explained.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.
    Keck UCal

    Keck NASA

    Keck Caltech

     
  • richardmitnick 3:16 pm on July 30, 2015 Permalink | Reply
    Tags: , Basic Research,   

    From Keck: “Keck Observatory Names Chief Scientist” 

    Keck Observatory

    Keck Observatory

    Keck Observatory

    July 30, 2015
    Steve Jefferson
    W. M. Keck Observatory
    sjefferson@keck.hawaii.edu
    808-881-3827

    1
    Anne L Kinney, Credit: NASA

    W. M. Keck Observatory is very pleased to announce Anne Kinney has been appointed Chief Scientist, effective August 3, 2015.

    “We are delighted to welcome Anne as the Chief Scientist of Keck Observatory,” said observatory Director, Hilton Lewis. “In this new role, she will be responsible for stewardship of the observatory’s scientific programs and for ensuring the health and vibrancy of the science conducted at this observatory.”

    Kinney comes to Keck Observatory from NASA, where she was most recently the Director of the Solar System Exploration Division at Goddard Space Flight Center. Kinney brings more than 30 years of scientific research and organizational leadership experience. She holds a PhD from New York University in Physics and Astronomy and is very familiar with Keck Observatory as she has been a member of the observatory’s Science Steering Committee since 2012.

    “It is my great pleasure to be joining the stellar Keck Observatory team,” Kinney said. “For me, one of the great attractions is the quality and dedication of its team. Keck Observatory’s international reputation speaks to the remarkable focus that the staff brings to extracting peak performance from two telescopes that are as beautiful as they are cutting edge.”

    Prior to her service at Goddard, Kinney was the Director of the Universe Division in the Science Mission Directorate at NASA Headquarters, with a portfolio including Hubble Space Telescope, Chandra X-ray Observatory, Spitzer Space Telescope, SOFIA, and Fermi.

    Kinney is an expert in extragalactic astronomy and has published 80 papers in refereed journals on quasars, blazars, active galaxies and normal galaxies, and signatures of accretion disks in active galaxies. She has demonstrated that accretion disks in the center of active galaxies lie at random angles relative to their host galaxies.

    Kinney received the Presidential Rank Award in 2012, has received two Exceptional Leadership Awards at NASA, and was a visiting scholar at the Institute of Astronomy in Cambridge.

    “I am thrilled that Anne has agreed to join us and contribute her energy and expertise to advance WMKO’s leadership in ground-based astronomy,” Lewis said.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.
    Keck UCal

    Keck NASA

    Keck Caltech

     
  • richardmitnick 3:00 pm on July 30, 2015 Permalink | Reply
    Tags: , Basic Research, , , , , ,   

    From Symmetry: “One Higgs is the loneliest number” 

    Symmetry

    July 30, 2015.
    Katie Elyce Jones

    Physicists discovered one type of Higgs boson in 2012. Now they’re looking for more.

    1

    When physicists discovered the Higgs boson in 2012, they declared the Standard Model of particle physics complete; they had finally found the missing piece of the particle puzzle.

    2
    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    And yet, many questions remain about the basic components of the universe, including: Did we find the one and only type of Higgs boson? Or are there more?

    A problem of mass

    The Higgs mechanism gives mass to some fundamental particles, but not others. It interacts strongly with W and Z bosons, making them massive. But it does not interact with particles of light, leaving them massless.

    These interactions don’t just affect the mass of other particles, they also affect the mass of the Higgs. The Higgs can briefly fluctuate into virtual pairs of the particles with which it interacts.

    Scientists calculate the mass of the Higgs by multiplying a huge number—related to the maximum energy for which the Standard Model applies—with a number related to those fluctuations. The second number is determined by starting with the effects of fluctuations to force-carrying particles like the W and Z bosons, and subtracting the effects of fluctuations to matter particles like quarks.

    While the second number cannot be zero because the Higgs must have some mass, almost anything it adds up to, even at very small numbers, makes the mass of the Higgs gigantic.

    But it isn’t. It weighs about 125 billion electronvolts; it’s not even the heaviest fundamental particle.

    “Having the Higgs boson at 125 GeV is like putting an ice cube into a hot oven and it not melting,” says Flip Tanedo, a theoretical physicist and postdoctoral researcher at the University of California, Irvine.

    A lightweight Higgs, though it makes the Standard Model work, doesn’t necessarily make sense for the big picture. If there are multiple Higgses—much heavier ones—the math determining their masses becomes more flexible.

    “There’s no reason to rule out multiple Higgs particles,” says Tim Tait, a theoretical physicist and professor at UCI. “There’s nothing in the theory that says there shouldn’t be more than one.”

    The two primary theories that predict multiple Higgs particles are Supersymmetry and compositeness.

    Supersymmetry standard model
    Standard Model of Supersymmetry

    Supersymmetry

    Popular in particle physics circles for tying together all the messy bits of the Standard Model, Supersymmetry predicts a heavier (and whimsically named) partner particle, or “sparticle,” for each of the known fundamental particles. Quarks have squarks and Higgs have Higgsinos.

    “When the math is re-done, the effects of the particles and their partner particles on the mass of the Higgs cancel each other out and the improbability we see in the Standard Model shrinks and maybe even vanishes,” says Don Lincoln, a physicist at Fermi National Accelerator Laboratory.

    The Minimal Supersymmetric Standard Model—the supersymmetric model that most closely aligns with the current Standard Model—predicts four new Higgs particles in addition to the Higgs sparticle, the Higgsino.

    While Supersymmetry is maybe the most popular theory for exploring physics beyond the Standard Model, physicists at the LHC haven’t seen any evidence of it yet. If Supersymmetry exists, scientists will need to produce more massive particles to observe it.

    “Scientists started looking for Supersymmetry five years ago in the LHC,” says Tanedo. “But we don’t really know where they will find it: 10 TeV? 100 TeV?”

    Compositeness

    The other popular theory that predicts multiple Higgs bosons is compositeness. The composite Higgs theory proposes that the Higgs boson is not a fundamental particle but is instead made of smaller particles that have not yet been discovered.

    “You can think of this like the study of the atom,” says Bogdan Dobrescu, a theoretical physicist at Fermi National Accelerator Laboratory. “As people looked closer and closer, they found the proton and neutron. They looked closer again and found the ‘up’ and ‘down’ quarks that make up the proton and neutron.”

    Composite Higgs theories predict that if there are more fundamental parts to the Higgs, it may assume a combination of masses based on the properties of these smaller particles.

    The search for composite Higgs bosons has been limited by the scale at which scientists can study given the current energy levels at the LHC.

    On the lookout

    Physicists will continue their Higgs search with the current run of the LHC.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    At 60 percent higher energy, the LHC will produce Higgs bosons more frequently this time around. It will also produce more top quarks, the heaviest particles of the Standard Model. Top quarks interact energetically with the Higgs, making them a favored place to start picking at new physics.

    Whether scientists find evidence for Supersymmetry or a composite Higgs (if they find either), that discovery would mean much more than just an additional Higgs.

    “For example, finding new Higgs bosons could affect our understanding of how the fundamental forces unify at higher energy,” Tait says.

    “Supersymmetry would open up a whole ‘super’ world out there to discover. And a composite Higgs might point to new rules on the fundamental level beyond what we understand today. We would have new pieces of the puzzle to look at it.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 11:16 am on July 30, 2015 Permalink | Reply
    Tags: , Basic Research,   

    From U Hawaii: “Robotically Discovering Earth’s Nearest Neighbors” 

    U Hawaii

    University of Hawaii

    July 30, 2015

    A team of astronomers using ground-based telescopes in Hawaii, California, and Arizona recently discovered a planetary system orbiting a nearby star that is only 54 light-years away. All three planets orbit their star at a distance closer than Mercury orbits the sun, completing their orbits in just 5, 15, and 24 days.

    Astronomers from the University of Hawaii at Manoa, the University of California, Berkeley, the University of California Observatories, and Tennessee State University found the planets using measurements from the Automated Planet Finder (APF) Telescope at Lick Observatory in California, the W. M. Keck Observatory on Maunakea, Hawaii, and the Automatic Photometric Telescope (APT) at Fairborn Observatory in Arizona.

    UC Observatories Lick APF
    UCO Lick APF

    Keck Observatory
    Keck Observatory Interior
    Keck

    U Arizona APT Fairborn
    APT at Fairborn

    The team discovered the new planets by detecting the wobble of the star HD 7924 as the planets orbited and pulled on the star gravitationally. APF and Keck Observatory traced out the planets’ orbits over many years using the Doppler technique that has successfully found hundreds of mostly larger planets orbiting nearby stars. APT made crucial measurements of the brightness of HD 7924 to assure the validity of the planet discoveries.

    1
    HD7924

    Artist’s impression of a view from the HD 7924 planetary system looking back toward our sun, which would be easily visible to the naked eye. Since HD 7924 is in our northern sky, an observer looking back at the sun would see objects like the Southern Cross and the Magellanic Clouds close to our sun in their sky. Art by Karen Teramura & BJ Fulton, UH IfA.

    The new APF facility offers a way to speed up the planet search. Planets can be discovered and their orbits traced much more quickly because APF is a dedicated facility that robotically searches for planets every clear night. Training computers to run the observatory all night, without human oversight, took years of effort by the University of California Observatories staff and graduate students on the discovery team.

    “We initially used APF like a regular telescope, staying up all night searching star to star. But the idea of letting a computer take the graveyard shift was more appealing after months of little sleep. So we wrote software to replace ourselves with a robot,” said University of Hawaii graduate student BJ Fulton.

    The Keck Observatory found the first evidence of planets orbiting HD 7924, discovering the innermost planet in 2009 using the HIRES instrument installed on the 10-meter Keck I telescope.

    Keck HIRES
    Keck HIRES

    This same combination was also used to find other super-Earths orbiting nearby stars in planet searches led by UH astronomer Andrew Howard and UC Berkeley Professor Geoffrey Marcy. It took five years of additional observations at Keck Observatory and the year-and-a-half campaign by the APF Telescope to find the two additional planets orbiting HD 7924.

    The Kepler Space Telescope has discovered thousands of extrasolar planets and demonstrated that they are common in our Milky Way galaxy.

    NASA Kepler Telescope
    Kepler

    However, nearly all of these planets are far from our solar system. Most nearby stars have not been thoroughly searched for the small “super-Earth” planets (larger than Earth but smaller than Neptune) that Kepler found in great abundance.

    This discovery shows the type of planetary system that astronomers expect to find around many nearby stars in the coming years. “The three planets are unlike anything in our solar system, with masses 7-8 times the mass of Earth and orbits that take them very close to their host star,” explains UC Berkeley graduate student Lauren Weiss.

    “This level of automation is a game-changer in astronomy,” says Howard. “It’s a bit like owning a driverless car that goes planet shopping.”

    Observations by APF, APT, and Keck Observatory helped verify the planets and rule out other explanations. “Starspots, like sunspots on the sun, can momentarily mimic the signatures of small planets. Repeated observations over many years allowed us to separate the starspot signals from the signatures of these new planets,” explains Evan Sinukoff, a UH graduate student who contributed to the discovery.

    The robotic observations of HD 7924 are the start of a systematic survey for super-Earth planets orbiting nearby stars. Fulton will lead this two-year search with the APF as part of his research for his doctoral dissertation. “When the survey is complete we will have a census of small planets orbiting sun-like stars within approximately 100 light-years of Earth,” says Fulton.

    Telescope automation is relatively new to astronomy, and UH astronomers are building two forefront facilities. Christoph Baranec built the Robo-AO observatory to takes high-resolution images using a laser to remove the blur of Earth’s atmosphere, and John Tonry is developing ATLAS, a robotic observatory that will hunt for killer asteroids.

    The paper presenting this work, “Three super-Earths orbiting HD 7924,” has been accepted for publication in the Astrophysical Journal and is available at no cost at http://arxiv.org/abs/1504.06629. The other authors of the paper are Howard Isaacson (UC Berkeley), Gregory Henry (TSU), and Bradford Holden and Robert I. Kibrick (UCO).

    n honor of the donations of Gloria and Ken Levy that helped facilitate the construction of the Levy spectrograph on APF and supported Lauren Weiss, the team has informally named the HD 7924 system the “Levy Planetary System.” The team also acknowledges the support of NASA, the U.S. Naval Observatory, and the University of California for its support of Lick Observatory.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    System Overview

    The University of Hawai‘i System includes 10 campuses and dozens of educational, training and research centers across the Hawaiian Islands. As the public system of higher education in Hawai‘i, UH offers opportunities as unique and diverse as our Island home.

    The 10 UH campuses and educational centers on six Hawaiian Islands provide unique opportunities for both learning and recreation.

    UH is the State’s leading engine for economic growth and diversification, stimulating the local economy with jobs, research and skilled workers.

     
  • richardmitnick 10:25 am on July 30, 2015 Permalink | Reply
    Tags: Basic Research, , ,   

    From FNAL: “Fishing for the weak and the charmed” 

    FNAL Home

    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    July 30, 2015
    Keith Matera and Andy Beretvas

    Temp 1
    The top plot shows the observed and predicted rates of vector boson plus charmed meson production at different energies for a type of vector boson called a W boson. The bottom plot shows the ratio of the observed to predicted rates. Observation and prediction are in agreement even at low energies, providing confirmation that we understand how these events behave. A well-tested model makes it easier to pick out anomalies, such as dark matter candidates.

    You collect coins, and you’re on the trail of a legend: According to rumor, a manufacturing defect led to one in every thousand 1939 nickels replacing Thomas Jefferson with a Sasquatch (also known as Bigfoot). But all of these weathered nickels now look about the same. How can you tell that you have found your elusive quarry?

    Finding something new in particle physics is much the same. We frequently know roughly what a new particle might look like, but this “signature” is often similar to that of other particles. One of the best ways to aid our search is to paint extremely accurate pictures of known particles and then look for exceptions to that rule.

    Heavy particles like dark matter candidates, the Higgs boson or particles predicted by supersymmetry share a common signature: They may decay into particles including a “vector boson V,” (a type of particle that transmits the weak force), and a “charmed meson,” D* (a particle made of two quarks, one of which is a charm quark).

    CDF physicists performed a search for these V+D* events — the normal nickels — to make certain that our picture of them is accurate.

    FNAL CDF
    CDF

    Models of events such as these are known to be accurate at high energies; however, at lower energies, subtleties in the strong force that binds together fundamental particles become more important, and the models may break down.

    This study was the first to test V+D* production at lower energies in hadron collisions. The V particle is either the W boson or the Z boson. The full Tevatron Run II data sample was used (9.7 inverse femtobarns).

    FNALTevatron
    Tevetron

    The figure shows the data when the V particle is the W particle. The experiment measured 634 ± 39 such events. The W particle is found by looking for an energetic lepton (a muon or an electron) and missing transverse energy (neutrino). The D* particle is observed from its decay into the D0 particle and a low-energy pion. The D0 decays into a negative kaon and a positive pion.

    Several sources of systematic uncertainty cancel in calculating the ratio of the decay probabilities for these two processes. We found that V+D* production behaves just as predicted. Providing such a stringent test of these models widens the net that we can cast in future studies. This, in turn, betters our chances of fishing out something new and exciting, perhaps previously undiscovered particles or particle decays.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.

     
  • richardmitnick 9:43 am on July 30, 2015 Permalink | Reply
    Tags: , Basic Research,   

    From CSIRO: “The ingredients (and our vision) for a smart society” 

    CSIRO bloc

    Commonwealth Scientific and Industrial Research Organisation

    July 30, 2015
    Carol Saab

    1

    When I say ‘science’ you say ‘beaker’. When I say ‘science’ you say ‘white lab coats’. When I say ‘science’ you say ‘microscopes’. Why is it so few people say ‘technology’ and ‘innovation’ and ‘collaboration’?

    Science is the essential building block for a smart society and it’s got much, much more to offer than the high-school science stereotype that plagues us.

    We’ve been doing a lot of thinking about where we’re headed, about our science masterplan for the next five years, and for us, science and innovation are inextricably linked.

    But there are some challenges around Australia’s ability to be innovative. Currently Australia ranks 81st in world rankings for innovation efficiency. This is the bang for our buck we get when we transform innovation investment into results. If Australia ranked 81st in the world in a sport, ANY sport, we’d be outraged. Even New Zealand is ahead of us in this game.

    Australia needs to pick up the game on ‘breakthrough innovation’ by creating new products and services – and potentially whole industries. We want to be at the centre of this, as the linchpin between business, government and the community.

    And we’ve identified ways in which we’ll succeed in this new vision:

    Crowd-sourcing

    We already have 5,000 of the best and brightest minds in Australia. The great ideas are out there, we just need to find them. This year we crowd-sourced ideas from our staff, customers and thought leaders to set the direction for our 2015-2020 strategy.

    Collaboration

    Innovation is a team sport. We want to increase our connection with universities and other research organisations. We want more student engagement, to bring dynamism and vibrancy to our work culture.

    Entrepreneurialism

    True disruption comes with risk-taking and agility. We’ve set up a targeted fund for new commercial venture ideas from our people. This intensive accelerator program will involve external entrepreneurs, investors and some of our large industry customers.

    Customer

    We always have to start the conversation by asking the questions – who is the customer, what value do they need, and are we delivering? Our science should always deliver real impact.

    Yes, real impact – the kind that makes your life better in some tangible way. This is not something new to us; we are well positioned to be Australia’s innovation catalyst. We are, after all, Australia’s largest patent holder and we’ve got 90 years of science impact under our belt.

    2

    Here’s just a few examples of how our innovation is already all around you:

    1. The smart tech that’s keeping you snug at work.

    Our OptiCOOL intelligent control technology uses lots of inputs, like weather, energy pricing and feedback from occupants, to adjust a building’s air-conditioning system and reduce energy consumption. The results? Up to 30 per cent reduction in energy use in 15 million square feet of floor space in Australia. That could include your desk at work.

    2. The long-wear contact lenses you put in this morning.

    Contact lenses were a game-changer last century, but they were rigid and not for night-time use. In 1991 we spearheaded an international collaboration that looked at using smarter materials to create a product that customers had been asking for. Ten years later and silicone hydrogen soft contact lenses made it onto the market and were an instant success. You’re welcome, eyeballs.

    3. The fast WiFi you’re using on your phone or laptop or tablet.

    There was life before WiFi? Well, not really. There was something, but it was a bit sad and lonely. Our astronomers set out to solve a ‘reverberation challenge’ to help them piece together the waves from black holes and from that wireless LAN was born. WiFi is now a fundamental part of our modern lives. Just consider how many times you’ve used it this last week.

    4. The cotton on your shoulders, or legs, or feet.

    Agriculture is a major player in the Australian economy but we’re always looking for efficiencies – less pesticides, better water use, higher yields. Since 1984 we’ve been doing just that, and now Australian cotton has the highest yields in the world, and more than 95 per cent of it is grown from our varieties.

    5. The cereal you’re eating that contains more fibre than any other.

    If you’re not a BARLEYmax fan, you should be. Our high fibre whole grain has two times the dietary fibre and four times the resistant starch of a regular grain. This superfood has the potential for lowering rates of type 2 diabetes, cardiovascular disease and colorectal cancer.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

     
  • richardmitnick 9:31 am on July 30, 2015 Permalink | Reply
    Tags: Basic Research, , , , ,   

    From livescience: “Origin-of-Life Story May Have Found Its Missing Link” 

    Livescience

    June 06, 2015
    Jesse Emspak

    1
    A field of geysers called El Tatio located in northern Chile’s Andes Mountains. Credit: Gerald Prins

    How did life on Earth begin? It’s been one of modern biology’s greatest mysteries: How did the chemical soup that existed on the early Earth lead to the complex molecules needed to create living, breathing organisms? Now, researchers say they’ve found the missing link.

    Between 4.6 billion and 4.0 billion years ago, there was probably no life on Earth. The planet’s surface was at first molten and even as it cooled, it was getting pulverized by asteroids and comets. All that existed were simple chemicals. But about 3.8 billion years ago, the bombardment stopped, and life arose. Most scientists think the “last universal common ancestor” — the creature from which everything on the planet descends — appeared about 3.6 billion years ago.

    But exactly how that creature arose has long puzzled scientists. For instance, how did the chemistry of simple carbon-based molecules lead to the information storage of ribonucleic acid, or RNA?

    2
    A hairpin loop from a pre-mRNA. Highlighted are the nucleobases (green) and the ribose-phosphate backbone (blue). Note that this is a single strand of RNA that folds back upon itself.

    The RNA molecule must store information to code for proteins. (Proteins in biology do more than build muscle — they also regulate a host of processes in the body.)

    The new research — which involves two studies, one led by Charles Carter and one led by Richard Wolfenden, both of the University of North Carolina — suggests a way for RNA to control the production of proteins by working with simple amino acids that does not require the more complex enzymes that exist today. [7 Theories on the Origin of Life on Earth]

    Missing RNA link

    This link would bridge this gap in knowledge between the primordial chemical soup and the complex molecules needed to build life. Current theories say life on Earth started in an “RNA world,” in which the RNA molecule guided the formation of life, only later taking a backseat to DNA, which could more efficiently achieve the same end result.

    3
    The structure of the DNA double helix. The atoms in the structure are colour-coded by element and the detailed structure of two base pairs are shown in the bottom right.

    Like DNA, RNA is a helix-shaped molecule that can store or pass on information. (DNA is a double-stranded helix, whereas RNA is single-stranded.) Many scientists think the first RNA molecules existed in a primordial chemical soup — probably pools of water on the surface of Earth billions of years ago. [Photo Timeline: How the Earth Formed]

    The idea was that the very first RNA molecules formed from collections of three chemicals: a sugar (called a ribose); a phosphate group, which is a phosphorus atom connected to oxygen atoms; and a base, which is a ring-shaped molecule of carbon, nitrogen, oxygen and hydrogen atoms. RNA also needed nucleotides, made of phosphates and sugars.

    The question: How did the nucleotides come together within the soupy chemicals to make RNA? John Sutherland, a chemist at the University of Cambridge in England, published a study in May in the journal Nature Chemistry that showed that a cyanide-based chemistry could make two of the four nucleotides in RNA and many amino acids.

    That still left questions, though. There wasn’t a good mechanism for putting nucleotides together to make RNA. Nor did there seem to be a natural way for amino acids to string together and form proteins. Today, adenosine triphosphate (ATP) does the job of linking amino acids into proteins, activated by an enzyme called aminoacyl tRNA synthetase. But there’s no reason to assume there were any such chemicals around billions of years ago.

    Also, proteins have to be shaped a certain way in order to function properly. That means RNA has to be able to guide their formation — it has to “code” for them, like a computer running a program to do a task.

    Carter noted that it wasn’t until the past decade or two that scientists were able to duplicate the chemistry that makes RNA build proteins in the lab. “Basically, the only way to get RNA was to evolve humans first,” he said. “It doesn’t do it on its own.”

    Perfect sizes

    In one of the new studies, Carter looked at the way a molecule called “transfer RNA,” or tRNA, reacts with different amino acids.

    They found that one end of the tRNA could help sort amino acids according to their shape and size, while the other end could link up with amino acids of a certain polarity. In that way, this tRNA molecule could dictate how amino acids come together to make proteins, as well as determine the final protein shape. That’s similar to what the ATP enzyme does today, activating the process that strings together amino acids to form proteins.

    Carter told Live Science that the ability to discriminate according to size and shape makes a kind of “code” for proteins called peptides, which help to preserve the helix shape of RNA.

    “It’s an intermediate step in the development of genetic coding,” he said.

    In the other study, Wolfenden and colleagues tested the way proteins fold in response to temperature, since life somehow arose from a proverbial boiling pot of chemicals on early Earth. They looked at life’s building blocks, amino acids, and how they distribute in water and oil — a quality called hydrophobicity. They found that the amino acids’ relationships were consistent even at high temperatures — the shape, size and polarity of the amino acids are what mattered when they strung together to form proteins, which have particular structures.

    “What we’re asking here is, ‘Would the rules of folding have been different?'” Wolfenden said. At higher temperatures, some chemical relationships change because there is more thermal energy. But that wasn’t the case here.

    By showing that it’s possible for tRNA to discriminate between molecules, and that the links can work without “help,” Carter thinks he’s found a way for the information storage of chemical structures like tRNA to have arisen — a crucial piece of passing on genetic traits. Combined with the work on amino acids and temperature, it offers insight into how early life might have evolved.

    This work still doesn’t answer the ultimate question of how life began, but it does show a mechanism for the appearance of the genetic codes that pass on inherited traits, which got evolution rolling.

    The two studies are published in the June 1 issue of the journal Proceedings of the National Academy of Sciences.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 9:06 am on July 30, 2015 Permalink | Reply
    Tags: , Basic Research, , Panspermia   

    From New Scientist: “Clusters of living worlds would hint life came from outer space” 

    NewScientist

    New Scientist

    29 July 2015
    Joshua Sokol

    1
    Panspermia would give rise to some lively stellar neighbourhoods (Image: NASA/JPL-Caltech)

    Does life spread like an interstellar infection? If we spot it on clusters of planets, that might suggest it doesn’t stay put wherever it evolves.

    The theory that life crosses space to reach new worlds, called panspermia, is hard to test. Life on Earth could have been seeded by just one microbe-laden rock, but there are too many rocks to check, even if we had a foolproof test for extraterrestrial life.

    “That’s not a very effective strategy of testing whether life came from outer space,” says Henry Lin of Harvard University. He says the answer lies in mapping life across the galaxy.

    Future probes like NASA’S James Webb Space Telescope will scrutinise the atmospheres of planets in other solar systems for possible signs of biological activity.

    NASA James Webb Telescope
    Webb

    If life spreads between planets, inhabited worlds should clump in space like colonies of bacteria on a Petri dish. Otherwise, Lin says, its signature would be seen on just a few, randomly scattered planets.

    Radiating life

    Lin argues that if we find 25 worlds with life on one side of the sky and 25 lifeless ones on the other, it might mean the sun sits on the edge of a panspermia bubble – a strong sign that life radiated outward. “We would have smoking-gun evidence that panspermia actually happens,” he says.

    But panspermia would be harder to confirm from the bubble’s centre. If there are biosignatures all around as far as we can see, for example, we can’t draw conclusions one way or the other. And if we see only scattered life, Lin says, that could suggest either that panspermia doesn’t happen or that it proceeds so slowly as to be rare.

    Sara Seager of the Massachusetts Institute of Technology, an expert on the hypothetical biosignatures the technique relies on, doubts Lin’s scenarios will come in handy any time soon. “It would be great if there’s a time in which we have so many biosignatures that we see clumps throughout the galaxy. But I don’t know when that time will be,” she says. “Until we find biosignatures we can’t actually proceed with any of this work.”

    Whether we manage to detect biosignatures or not, Lin thinks his work might have a second life in the distant future, if humans achieve interstellar travel. The spread of humans and other organisms riding our coat-tails would follow the same growth pattern, he says.

    “Even if panspermia doesn’t happen, we might be the ones to bring it about. Maybe this paper will be useful a thousand years from now,” he says.

    Journal reference: arxiv.org/abs/1507.05614

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
Follow

Get every new post delivered to your Inbox.

Join 452 other followers

%d bloggers like this: