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Pulsars: The Universe’s Gift to Physics

February 20, 2012 Leave a comment

Pulsars, superdense neutron stars, are perhaps the most extraordinary physics laboratories in the Universe. Research on these extreme and exotic objects already has produced two Nobel Prizes. Pulsar researchers now are poised to learn otherwise-unavailable details of nuclear physics, to test General Relativity in conditions of extremely strong gravity, and to directly detect gravitational waves with a “telescope” nearly the size of our Galaxy.

Neutron stars are the remnants of massive stars that exploded as supernovae. They pack more than the mass of the Sun into a sphere no larger than a medium-sized city, making them the densest objects in the Universe, except for black holes, for which the concept of density is theoretically irrelevant. Pulsars are neutron stars that emit beams of radio waves outward from the poles of their magnetic fields. When their rotation spins a beam across the Earth, radio telescopes detect that as a “pulse” of radio waves.

By precisely measuring the timing of such pulses, astronomers can use pulsars for unique “experiments” at the frontiers of modern physics. Three scientists presented the results of such work, and the promise of future discoveries, at the American Association for the Advancement of Science meeting in Vancouver, British Columbia.

Full Story: http://www.nrao.edu/pr/2012/aaaspulsars/

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Cassini Significant Events 02/08/2012 – 02/14/2012

February 20, 2012 Leave a comment

The most recent spacecraft tracking and telemetry data in this reporting period were acquired on Feb. 14 from the Deep Space Network 34 meter Station 55 in Madrid, Spain. The Cassini spacecraft is in an excellent state of health. All subsystems are operating normally except for the issues being worked with the Cassini Plasma Spectrometer and the Ultrastable Oscillator. Information on the present position of the Cassini spacecraft may be found on the “Present Position” page at:http://saturn.jpl.nasa.gov/mission/presentposition/.

This week the Cassini science instruments made several observations called TEAs – Titan Exploration from Apoapsis. This campaign makes frequent distant observations over periods of days to weeks under illumination at low to moderate phase angles. Rain clouds are infrequent on Titan, so TEA observations provide a good chance to document coincident atmospheric and surface changes. The Imaging Science Subsystem (ISS), the Composite Infrared Spectrometer (CIRS), and the Visual and Infrared Mapping Spectrometer (VIMS) participate in TEAs.

The ISS team performed another observation in its Satellite Orbit Campaign, observing several small inner moons, and the VIMS team conducted several observations in the Saturn Storm Watch series and the Titan Monitoring Campaign.

Full Story: http://saturn.jpl.nasa.gov/news/significantevents/significantevents20120216/