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    "results": [
        {
            "id": 11553,
            "url": "https://svs.gsfc.nasa.gov/11553/",
            "result_type": "Produced Video",
            "release_date": "2014-05-30T13:00:00-04:00",
            "title": "WFIRST: Uncovering the Mysteries of the Universe",
            "description": "The Wide-Field Infrared Survey Telescope (WFIRST) is an upcoming space telescope designed to perform wide-field imaging and spectroscopy of the infrared sky. One of WFIRST’s objectives will be looking for clues about dark energy—the mysterious force that is accelerating the expansion of the universe.  Another objective of the mission will be finding and studying exoplanets. WFIRST uses the same 2.4 meter telescope size as Hubble, but with 18 cutting-edge fourth-generation image sensors compared to Hubble's single first-generation sensor. As a result, each WFIRST image will cover over 200 times as much as a Hubble Wide Field Camera 3/IR image and be 300 megapixels in size.  Hubble images reveal thousands of galaxies; a single WFIRST image will uncover millions.To help uncover the mystery of dark energy, WFIRST will make incredibly precise measurements of the universe.  These measurements, like the distance and position of galaxies, can be compared to other measurements—such as the cosmic microwave background from the WMAP mission—to determine how dark energy has changed over time.  WFIRST can also measure the slight distortions in light from distant galaxies as it passes more nearby mass concentrations.  These data will build a three dimensional picture of how mass is distributed throughout the universe, and provide independent confirmation of its structure.Because WFIRST has such a large and sensitive field of view, it can find thousands of new exoplanets through a process called microlensing. When one star in the sky appears to pass nearly in front of another, the light rays of the background source star become bent due to the gravitational \"attraction\" of the foreground star. This \"lens\" star is then a virtual magnifying glass, amplifying the brightness of the background source star. If the lens star harbors a planetary system, then those planets can also act as lenses, each one producing a short deviation in the brightness of the source.  For closer planets, WFIRST will open a new era of direct observation.  Currently only a handful of planets are observable in light reflected off of them, and they are all large planets close to their stars.  WFIRST will be able to detect planets as small as Neptune, and as far from their stars as Saturn is from the sun.  This is possible thanks to newly developed  coronagraphs, which block the bright light from the star to make the planet more visible. || ",
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        {
            "id": 10943,
            "url": "https://svs.gsfc.nasa.gov/10943/",
            "result_type": "Produced Video",
            "release_date": "2012-04-02T12:30:00-04:00",
            "title": "Fermi Observations of Dwarf Galaxies Provide New Insights on Dark Matter",
            "description": "There's more to the cosmos than meets the eye. About 80 percent of the matter in the universe is invisible to telescopes, yet its gravitational influence is manifest in the orbital speeds of stars around galaxies and in the motions of clusters of galaxies. Yet, despite decades of effort, no one knows what this \"dark matter\" really is. Many scientists think it's likely that the mystery will be solved with the discovery of new kinds of subatomic particles, types necessarily different from those composing atoms of the ordinary matter all around us. The search to detect and identify these particles is underway in experiments both around the globe and above it. Scientists working with data from NASA's Fermi Gamma-ray Space Telescope have looked for signals from some of these hypothetical particles by zeroing in on 10 small, faint galaxies that orbit our own. Although no signals have been detected, a novel analysis technique applied to two years of data from the observatory's Large Area Telescope (LAT) has essentially eliminated these particle candidates for the first time.WIMPs, or Weakly Interacting Massive Particles, represent a favored class of dark matter candidates. Some WIMPs may mutually annihilate when pairs of them interact, a process expected to produce gamma rays — the most energetic form of light — that the LAT is designed to detect. The team examined two years of LAT-detected gamma rays with energies in the range from 200 million to 100 billion electron volts (GeV) from 10 of the roughly two dozen dwarf galaxies known to orbit the Milky Way. Instead of analyzing the results for each galaxy separately, the scientists developed a statistical technique — they call it a \"joint likelihood analysis\" — that evaluates all of the galaxies at once without merging the data together. No gamma-ray signal consistent with the annihilations expected from four different types of commonly considered WIMP particles was found.For the first time, the results show that WIMP candidates within a specific range of masses and interaction rates cannot be dark matter. A paper detailing these results appeared in the Dec. 9, 2011, issue of Physical Review Letters. || ",
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