• Category Archives Space

  • Sally Ride, first US woman in space, dies at 61

    Posted on by Azrael Comment

    Space used to be a man’s world. Then came Sally Ride, who blazed a cosmic trail for U.S. women into orbit. With a pitch perfect name out of a pop song refrain, she joined the select club of American space heroes the public knew by heart: Shepard, Glenn, Armstrong and Aldrin.

    Ride, the first American woman in orbit, died Monday at her home in the San Diego community of La Jolla at age 61. The cause was pancreatic cancer, an illness she had for 17 months, according to her company, Sally Ride Science.

    Ride rode into space on the space shuttle Challenger on June 18, 1983, when she was 32. Since then, 42 other American women flew in space.

    “Sally was a national hero and a powerful role model. She inspired generations of young girls to reach for the stars,” President Barack Obama said in a statement.

    When shuttles started flying frequently with crews of six or seven, astronauts became plentiful and anonymous. Not Ride.

    “People around the world still recognize her name as the first American woman in space, and she took that title seriously even after departing NASA,” Eileen Collins, the first female space shuttle commander, said in a statement. “She never sought media attention for herself, but rather focused on doing her normally outstanding job.”

    Full article: http://www.boston.com/news/nation/articles/2012/07/23/sally_ride_first_us_woman_in_space_dies_at_61/


    Space 📎and tagged

  • Decades-Old ‘Pioneer Anomaly’ Mystery Finally Solved

    Posted on by Azrael Comment

    Scientists have finally cracked a decades-old spaceflight riddle, figuring out why NASA’s Pioneer 10 and 11 probes began to slow mysteriously as they sped far from the sun.

    The cause of the so-called “Pioneer Anomaly,” it turns out, is heat coming from the electrical current flowing through the probes’ instrument and power systems. This heat pushed back on the spacecraft, causing them to decelerate slightly, according to a new study.

    “The effect is something like when you’re driving a car and the photons from your headlights are pushing you backward,” lead author Slava Turyshev, of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., said in a statement. “It is very subtle.”

    Pioneer 10 and Pioneer 11 launched in 1972 and 1973, respectively. They were the first spacecraft to fly through the main asteroid belt, and the first to study Jupiter up-close. The probes kept on cruising after their Jupiter encounters, speeding toward Saturn and beyond.

    Pioneer 10 and 11 will eventually exit the solar system, but they likely won’t be the first to do so. Scientists think the Voyager 1 spacecraft, which is about 11.1 billion miles (17.8 billion kilometers) from Earth, may leave our cosmic neighborhood any day now.

    Full article: http://www.space.com/16648-pioneer-anomaly-spacecraft-mystery-solved.html


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  • NASA’S Spitzer Finds Evidence for an Exoplanet Smaller than Earth

    Posted on by Azrael Comment

    J.D. Harrington
    Headquarters, Washington
    202-358-5241
    j.d.harrington@nasa.gov

    Whitney Clavin
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-4673
    whitney.clavin@jpl.nasa.gov
    July 18, 2012

    RELEASE : 12-238

    NASA’S Spitzer Finds Evidence for an Exoplanet Smaller than Earth

    WASHINGTON — Astronomers using NASA’s Spitzer Space Telescope have detected what they believe is a planet two-thirds the size of Earth. The exoplanet candidate, called UCF-1.01, is located a mere 33 light-years away, making it possibly the nearest world to our solar system that is smaller than our home planet.

    Exoplanets circle stars beyond our sun. Only a handful smaller than Earth have been found so far. Spitzer has performed transit studies on known exoplanets, but UCF-1.01 is the first ever identified with the telescope, pointing to a possible role for Spitzer in helping discover potentially habitable, terrestrial-sized worlds.

    “We have found strong evidence for a very small, very hot and very near planet with the help of the Spitzer Space Telescope,” said Kevin Stevenson from the University of Central Florida in Orlando. Stevenson is lead author of the paper, which has been accepted for publication in The Astrophysical Journal. “Identifying nearby small planets such as UCF-1.01 may one day lead to their characterization using future instruments.”

    The hot new planet candidate was found unexpectedly in Spitzer observations. Stevenson and his colleagues were studying the Neptune-sized exoplanet GJ 436b, already known to exist around the red-dwarf star GJ 436. In the Spitzer data, the astronomers noticed slight dips in the amount of infrared light streaming from the star, separate from the dips caused by GJ 436b. A review of Spitzer archival data showed the dips were periodic, suggesting a second planet might be blocking out a small fraction of the star’s light.

    This technique, used by a number of observatories including NASA’s Kepler space telescope, relies on transits to detect exoplanets. The duration of a transit and the small decrease in the amount of light registered reveals basic properties of an exoplanet, such as its size and distance from its star. In UCF-1.01’s case, its diameter would be approximately 5,200 miles (8,400 kilometers), or two-thirds that of Earth. UCF-1.01 would revolve quite tightly around GJ 436, at about seven times the distance of the Earth from the moon, with its “year” lasting only 1.4 Earth days. Given this proximity to its star, far closer than the planet Mercury is to our sun, the exoplanet’s surface temperature would be more than 1,000 degrees Fahrenheit (almost 600 degrees Celsius).

    If the roasted, diminutive planet candidate ever had an atmosphere, it almost surely has evaporated. UCF-1.01 might therefore resemble a cratered, mostly geologically dead world like Mercury. Paper co-author Joseph Harrington, also of the University of Central Florida and principal investigator of the research, suggested another possibility; that the extreme heat of orbiting so close to GJ 436 has melted the exoplanet’s surface.

    “The planet could even be covered in magma,” Harrington said.

    In addition to UCF-1.01, Stevenson and his colleagues noticed hints of a third planet, dubbed UCF-1.02, orbiting GJ 436. Spitzer has observed evidence of the two new planets several times each. However, even the most sensitive instruments are unable to measure exoplanet masses as small as UCF-1.01 and UCF-1.02, which are perhaps only one-third the mass of the Earth. Because knowing the mass is required for confirming a discovery, the paper authors are cautiously calling both bodies exoplanet candidates for now.

    Of the approximately 1,800 stars identified by Kepler as candidates for having planetary systems, just three are verified to contain sub-Earth-sized exoplanets. Of these, only one exoplanet is thought to be smaller than the Spitzer candidates, with a radius similar to Mars, or 57 percent that of Earth.

    “I hope future observations will confirm these exciting results, which show Spitzer may be able to discover exoplanets as small as Mars,” said Michael Werner, Spitzer Project Scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “Even after almost nine years in space, Spitzer’s observations continue to take us in new and important scientific directions.”

    JPL manages Spitzer for NASA’s Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Caltech manages JPL for NASA.

    For more information about Spitzer, visit:

    http://www.nasa.gov/spitzer

    Full article: http://www.nasa.gov/home/hqnews/2012/jul/HQ_12-238_Spitzer_Small_Exoplanet.html


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