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Archive for September, 2012

NASA Rover Finds Old Streambed On Martian Surface

September 28, 2012 Leave a comment

NASA’s Curiosity rover found evidence for an ancient, flowing stream on Mars. Image credit: NASA/JPL-Caltech/MSSS

NASA’s Curiosity rover mission has found evidence a stream once ran vigorously across the area on Mars where the rover is driving. There is earlier evidence for the presence of water on Mars, but this evidence — images of rocks containing ancient streambed gravels — is the first of its kind.

Scientists are studying the images of stones cemented into a layer of conglomerate rock. The sizes and shapes of stones offer clues to the speed and distance of a long-ago stream’s flow.

“From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep,” said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. “Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them. This is the first time we’re actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2012-305#1

Peering To The Edge Of A Black Hole

September 28, 2012 Leave a comment

Black hole powered jet of sub-atomic particles. Credit: NASA and the Hubble Heritage Team

Using a continent-spanning telescope, an international team of astronomers has peered to the edge of a black hole at the center of a distant galaxy. For the first time, they have measured the black hole’s “point of no return” – the closest distance that matter can approach before being irretrievably pulled into the black hole.

A black hole is a region in space where the pull of gravity is so strong that nothing, not even light, can escape. Its boundary is known as the event horizon.

“Once objects fall through the event horizon, they’re lost forever,” says lead author Shep Doeleman, assistant director at the MIT Haystack Observatory and research associate at the Harvard-Smithsonian Center for Astrophysics (CfA). “It’s an exit door from our universe. You walk through that door, you’re not coming back.”

Full Story: http://www.cfa.harvard.edu/news/2012/pr201228.html

Cause Of Supernova SN 1006 Revealed

September 28, 2012 1 comment

Between 30 April and 1 May of the year 1006 the brightest stellar event ever recorded in history occurred: a supernova, or stellar explosion, that was widely observed by various civilizations from different places on the Earth. More than a thousand years later a team led by researchers from the University of Barcelona, the Instituto de Astrofísica de Canarias (IAC) and the CSIC has found that the supernova of 1006 (SN 1006) probably occurred as a result of the merger of two white dwarfs. The finding has been published in and made the front cover of today’s edition of the international science journal Nature.

Different communities of astronomers all over the world observed the supernova of the year 1006. Some of them, including Chinese astronomers, highlighted the fact that the astronomical event was visible for three years. The most explicit record, made by the Egyptian doctor and astronomer Ali ibn Ridwan (988-1061), notes that the phenomenon was about three times brighter than Venus, and that it emitted light of a quantity equivalent to almost a quarter of the Moon’s brightness.

As co-director of the work, Pilar Ruiz-Lapuenteexplains, “In this work the existing stars in the area have been studied, regarding distance and possible contamination by elements of the supernova, and the results show that there is no star that could be considered the progenitor of this explosion”.

Full Story: http://www.ub.edu/web/ub/en/menu_eines/noticies/2012/09/049.html

Navigating The Seas Of Titan

September 28, 2012 Leave a comment

Humanity has landed a rover on Mars. Now, say scientists, it’s time to land a boat on Titan. This outlandish scenario could become reality, according to engineers presenting their proposals at the European Planetary Science Congress on 27 September.

Titan, Saturn’s largest moon, is one of the most Earth-like bodies in the Solar System. With a thick atmosphere, a diameter between that of Earth and the planet Mercury, and a network of seas, lakes and rivers, it is in many respects more like a planet than a moon like the Earth’s.

The new plans, called the Titan Lake In-situ Sampling Propelled Explorer, proposes a boat-probe, propelled by wheels, paddles or screws. The probe would land in the middle of Ligeia Mare (the biggest lake, near Titan’s north pole), then set sail for the coast, taking scientific measurements along the way. The mission would last around six months to a year.

Full Story: http://www.europlanet-eu.org/outreach/index.php?option=com_content&task=view&id=391&Itemid=41

Fireworks In The Early Universe

September 28, 2012 Leave a comment

Artist impression (ESA/NASA/RUG
/MarcelZinger)

Galaxies in the early universe grew fast by rapidly making new stars. Such prodigious star formation episodes, characterized by the intense radiation of the newborn stars, were often accompanied by fireworks in the form of energy bursts caused by the massive central black hole accretion in these galaxies. This discovery by a group of astronomers led by Peter Barthel of the Kapteyn Institute of the University of Groningen in the Netherlands is published today in the Astrophysical Journal Letters.

Until recently these distant active galaxies were only interesting in their own right as peculiar exotic objects. Little was known about the composition of their galaxies, or their relationship to the normal galaxy population. However, in 2009 ESA’s Herschel space telescope was launched. Herschel is considerably larger than NASA’s Hubble, and operates at far-infrared wavelengths. This enables Herschel to detect heat radiation generated by the processes involved in the formation of stars and planets at a small scale, and of complete galaxies at a large scale.

Full Story: http://www.rug.nl/corporate/nieuws/archief/archief2012/nieuwsberichten/126-barthel

Sharpest-Ever Ground-Based Images Of Pluto And Charon: Proves A Powerful Tool For Exoplanet Discoveries

September 28, 2012 Leave a comment

Credit: Gemini Observatory/NSF/NASA/AURA

Despite being infamously demoted from its status as a major planet, Pluto (and its largest companion Charon) recently posed as a surrogate extrasolar planetary system to help astronomers produce exceptionally high-resolution images with the Gemini North 8-meter telescope. Using a method called reconstructive speckle imaging, the researchers took the sharpest ground-based snapshots ever obtained of Pluto and Charon in visible light, which hint at the exoplanet verification power of a large state-of-the-art telescope when combined with speckle imaging techniques. The data also verified and refined previous orbital characteristics for Pluto and Charon while revealing the pair’s precise diameters.

“The Pluto-Charon result is of timely interest to those of us wanting to understand the orbital dynamics of this pair for the 2015 encounter by NASA’s New Horizons spacecraft,” said Steve Howell of the NASA Ames Research Center, who led the study. In addition, Howell notes that NASA’s Kepler mission, which has already proven a powerful exoplanet discovery tool, will benefit greatly from this technique.

Full Story: http://www.gemini.edu/node/11893

Asteroid’s Troughs Suggest Stunted Planet

September 28, 2012 1 comment

Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Enormous troughs that reach across the asteroid Vesta may actually be stretch marks that hint of a complexity beyond most asteroids. Scientists have been trying to determine the origin of these unusual troughs since their discovery just last year. Now, a new analysis supports the notion that the troughs are faults that formed when a fellow asteroid smacked into Vesta’s south pole. The research reinforces the claim that Vesta has a layered interior, a quality normally reserved for larger bodies, such as planets and large moons.

Asteroid surface deformities are typically straightforward cracks formed by crashes with other asteroids. Instead, an extensive system of troughs encircles Vesta, the second most massive asteroid in the solar system, about one-seventh as wide as the Moon. The biggest of those troughs, named Divalia Fossa, surpasses the size of the Grand Canyon by spanning 465 kilometers (289 miles) long, 22 km (13.6 mi) wide and 5 km (3 mi) deep.

Full Story: