Monday, September 12, 2011

New Supernova Remnant Lights Up


Using the Hubble Space Telescope, astronomers are witnessing the unprecedented transition of a supernova to a supernova remnant, where light from an exploding star in a neighboring galaxy, the Large Magellanic Cloud, reached Earth in February 1987. Named Supernova 1987A, it was the closest supernova explosion witnessed in almost 400 years. The supernova's close proximity to Earth allows astronomers to study it in detail as it evolves. Now, the supernova debris, which has faded over the years, is brightening. This means that a different power source has begun to light the debris. The debris of SN 1987A is beginning to impact the surrounding ring, creating powerful shock waves that generate X-rays observed with NASA's Chandra X-ray Observatory. Those X-rays are illuminating the supernova debris and shock heating is making it glow in visible light. Since its launch in 1990, the Hubble telescope has provided a continuous record of the changes in SN 1987A.

Image Credit: NASA, ESA, and P. Challis (Harvard-Smithsonian Center for Astrophysics)

Friday, September 9, 2011

NASA's Viking Project found a place in history when it became the first U.S. mission to land a spacecraft successfully on the surface of Mars. Two identical spacecraft, each consisting of a lander and an orbiter, were built. Each orbiter-lander pair flew together and entered Mars orbit; the landers then separated and descended to the planet's surface. Viking 2 launched 36 years ago today on Sept. 9, 1975. This artist's concept depicts a Viking lander on the surface of Mars.

The Viking 2 lander settled down at Utopia Planitia on Sept. 3, 1976, while the Viking 1 Lander touched down on the western slope of Chryse Planitia (the Plains of Gold) on July 20, 1976.

Besides taking photographs and collecting other science data on the Red Planet's surface, the two landers conducted three biology experiments designed to look for possible signs of life. These experiments discovered unexpected and enigmatic chemical activity in the Martian soil, but provided no clear evidence for the presence of living microorganisms in soil near the landing sites. According to scientists, Mars is self-sterilizing. They believe the combination of solar ultraviolet radiation that saturates the surface, the extreme dryness of the soil and the oxidizing nature of the soil chemistry prevent the formation of living organisms in the Martian soil.

Although the Viking mission was planned to continue for 90 days after landing, each orbiter and lander operated far beyond its design lifetime. Viking Orbiter 1 functioned until July 25, 1978, while Viking Orbiter 2 continued for four years and 1,489 orbits of Mars, concluding its mission Aug. 7, 1980. Because of the variations in available sunlight, both landers were powered by radioisotope thermoelectric generators -- devices that create electricity from heat given off by the natural decay of plutonium. That power source allowed long-term science investigations that otherwise would not have been possible. The last data from Viking Lander 2 arrived at Earth on April 11, 1980. Viking Lander 1 made its final transmission to Earth Nov. 11, 1982.

Image Credit: NASA/JPL-Caltech/University of Arizona

Grail on the pad

NASA's GRAIL twin spacecraft await launch atop a United Launch Alliance Delta II rocket at Cape Canaveral Air Force Station, Fla.

Image credit: NASA/JPL-Caltech/United Launch Alliance, Thom Baur

Tropical Storm Maria (Atlantic Ocean)

Wed, 07 Sep 2011 23:00:00 -0500



Tropical Storm Maria appears smaller than Lee, Katia and Nate on today's GOES-13 visible satellite image

Tropical Storm Nate (Gulf of Mexico)

Wed, 07 Sep 2011 23:00:00 -0500



Nate appears as a small rounded area of clouds on today's GOES-13 satellite image.

Thursday, September 8, 2011

NASA Spacecraft Observes New Characteristics Of Solar Flares

Tue, 06 Sep 2011 23:00:00 -0500

NASA's Solar Dynamics Observatory, or SDO, has provided scientists new information about solar flares indicating an increase in strength and longevity that is more than previously thought.

Wednesday, September 7, 2011

The Moon's North Pole

Tue, 06 Sep 2011 23:00:00 -0500

The Earth's moon has been an endless source of fascination for humanity for thousands of years. When at last Apollo 11 landed on the moon's surface in 1969, the crew found a desolate, lifeless orb, but one which still fascinates scientist and non-scientist alike. This image of the moon's north polar region was taken by the Lunar Reconnaissance Orbiter Camera, or LROC. One of the primary scientific objectives of LROC is to identify regions of permanent shadow and near-permanent illumination. Since the start of the mission, LROC has acquired thousands of Wide Angle Camera images approaching the north pole. From these images, scientists produced this mosaic, which is composed of 983 images taken over a one month period during northern summer. This mosaic shows the pole when it is best illuminated, regions that are in shadow are candidates for permanent shadow. Image Credit: NASA/GSFC/Arizona State University