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Archive for February, 2013

World’s Smallest Space Telescope: Canada Helps Push The Boundaries Of Astronomy With The Next Wave Of Smaller Satellites

February 28, 2013 Leave a comment

The smallest astronomical satellite ever built will launch shortly after 07:20 a.m. EST on Monday, 25 February 2013 as part of a mission to prove that even a very small telescope can push the boundaries of astronomy.

The satellite was designed and assembled at the Space Flight Laboratory (SFL) of the University of Toronto Institute for Aerospace Studies (UTIAS). It will be launched from the Satish Dhawan Space Centre in Sriharikota, India, along with its twin, also designed in Canada, but assembled in Austria.

Each nano-satellite in the BRIght Target Explorer (BRITE) mission is a cube 20 centimetres per side, and weighing less than 7 kilograms. The BRITE satellites are part of the new wave of nano-satellites that can be designed, assembled and deployed fast and relatively cheaply.

“SFL has demonstrated that nano-satellites can be developed quickly, by a small team and at a cost that is within reach of many universities, small companies and other organizations,” says Cordell Grant, Manager of Satellite Systems for the Space Flight Laboratory at UTIAS. “A nano-satellite can take anywhere from six months to a few years to develop and test, but we typically aim for two years or less.”

Full Story, Videos and Photos: http://universe.utoronto.ca/BRITE

NASA Deciphering The Mysterious Math Of The Solar Wind

February 28, 2013 Leave a comment

Many areas of scientific research — Earth’s weather, ocean currents, the outpouring of magnetic energy from the sun — require mapping out the large scale features of a complex system and its intricate details simultaneously.

Describing such systems accurately, relies on numerous kinds of input, beginning with observations of the system, incorporating mathematical equations to approximate those observations, running computer simulations to attempt to replicate observations, and cycling back through all the steps to refine and improve the models until they jibe with what’s seen. Ultimately, the models successfully help scientists describe, and even predict, how the system works.

Understanding the sun and how the material and energy it sends out affects the solar system is crucial, since it creates a dynamic space weather system that can disrupt human technology in space such as communications and global positioning system (GPS) satellites.

However, the sun and its prodigious stream of solar particles, called the solar wind, can be particularly tricky to model since as the material streams to the outer reaches of the solar system it carries along its own magnetic fields. The magnetic forces add an extra set of laws to incorporate when trying to determine what’s governing the movement. Indeed, until now, equations for certain aspects of the solar wind have never been successfully devised to correlate to the observations seen by instruments in space. Now, for the first time, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., has created a set of the necessary equations, published in Physical Review Letters on Dec. 4, 2012.

Full Story: http://www.nasa.gov/mission_pages/sunearth/news/math-solarwind.html

Journey To The Limits Of Spacetime

February 28, 2013 Leave a comment

Voracious absences at the center of galaxies, black holes shape the growth and death of the stars around them through their powerful gravitational pull and explosive ejections of energy.

“Over its lifetime, a black hole can release more energy than all the stars in a galaxy combined,” said Roger Blandford, director of the Kavli Institute for Particle Astrophysics and Cosmology and a member of the U.S. National Academy of Science. “Black holes have a major impact on the formation of galaxies and the environmental growth and evolution of those galaxies.”

Gravitational forces grow so strong close to a black hole that even light cannot escape from within, hence the difficulty in observing them directly. Scientists infer facts about black holes by their influence on the astronomical objects around them: the orbit of stars and clumps of detectable energy. With this information in hand, scientists create computer models to understand the data and to make predictions about the physics of distant regions of space. However, models are only as good as their assumptions.

“All tests of general relativity in the weak gravity field limit, like in our solar system, fall directly along the lines of what Einstein predicted,” explained Jonathan McKinney, an assistant professor of physics at the University of Maryland at College Park. “But there is another regime—which has yet to be tested, and which is the hardest to test—that represents the strong gravitational field limit. And according to Einstein, gravity is strongest near black holes.”

Full Story and Video: http://www.tacc.utexas.edu/news/feature-stories/2012/journey-to-the-limits-of-spacetime

Stellar Motions In Outer Halo Shed New Light On Milky Way Evolution

February 23, 2013 Leave a comment

Peering deep into the vast stellar halo that envelops our Milky Way galaxy, astronomers using NASA’s Hubble Space Telescope have uncovered tantalizing evidence for the possible existence of a shell of stars that are a relic of cannibalism by our Milky Way.

Hubble was used to precisely measure, for the first time ever, the sideways motions of a small sample of stars located far from the galaxy’s center. Their unusual lateral motion is circumstantial evidence that the stars may be the remnants of a shredded galaxy that was gravitationally ripped apart by the Milky Way billions of years ago. These stars support the idea that the Milky Way grew, in part, through the accretion of smaller galaxies.

“Hubble’s unique capabilities are allowing astronomers to uncover clues to the galaxy’s remote past. The more distant regions of the galaxy have evolved more slowly than the inner sections. Objects in the outer regions still bear the signatures of events that happened long ago,” said Roeland van der Marel of the Space Telescope Science Institute (STScI) in Baltimore, Md.

Full Story: http://hubblesite.org/newscenter/archive/releases/2013/07/full/

ESA Chooses Instruments For Its Jupiter Icy Moons Explorer

February 23, 2013 Leave a comment

The JUpiter ICy moons Explorer mission, JUICE, will carry a total of 11 scientific experiments to study the gas giant planet and its large ocean-bearing moons, ESA announced today.

JUICE is the first Large-class mission in ESA’s Cosmic Vision 2015–2025 programme. Planned for launch in 2022 and arrival at Jupiter in 2030, it will spend at least three years making detailed observations of the biggest planet in the Solar System and three of its largest moons, Ganymede, Callisto and Europa.

These moons are thought to harbour vast water oceans beneath their icy surfaces and JUICE will map their surfaces, sound their interiors and assess their potential for hosting life in their oceans.

Full Story: http://www.esa.int/Our_Activities/Space_Science/ESA_chooses_instruments_for_its_Jupiter_icy_moons_explorer
Also: http://www.bis.gov.uk/ukspaceagency/news-and-events/2013/Feb/uk-led-instrument-selected-for-europes-jupiter-mission
Also: http://www.nasa.gov/home/hqnews/2013/feb/HQ_13-060_JUICE_Instruments.html
Also: http://www.swri.org/9what/releases/2013/juice.htm

Mercury May Have Harbored An Ancient Magma Ocean

February 23, 2013 Leave a comment

Photo: United States Geological Survey

Photo: United States Geological Survey

By analyzing Mercury’s rocky surface, scientists have been able to partially reconstruct the planet’s history over billions of years. Now, drawing upon the chemical composition of rock features on the planet’s surface, scientists at MIT have proposed that Mercury may have harbored a large, roiling ocean of magma very early in its history, shortly after its formation about 4.5 billion years ago.

The scientists analyzed data gathered by MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging), a NASA probe that has orbited the planet since March 2011. Later that year, a group of scientists analyzed X-ray fluorescence data from the probe, and identified two distinct compositions of rocks on the planet’s surface. The discovery unearthed a planetary puzzle: What geological processes could have given rise to such distinct surface compositions?

To answer that question, the MIT team used the compositional data to recreate the two rock types in the lab, and subjected each synthetic rock to high temperatures and pressures to simulate various geological processes. From their experiments, the scientists came up with only one phenomenon to explain the two compositions: a vast magma ocean that created two different layers of crystals, solidified, then eventually remelted into magma that then erupted onto Mercury’s surface.

Full Story: http://web.mit.edu/newsoffice/2013/mercury-may-have-harbored-ancient-magma-ocean-0221.html

A Simple View Of Gravity Does Not Fully Explain The Distribution Of Stars In Crowded Clusters

February 23, 2013 Leave a comment

Gravity remains the dominant force on large astronomical scales, but when it comes to stars in young star clusters the dynamics in these crowded environments cannot be simply explained by the pull of gravity. After analyzing Hubble Space Telescope images of star cluster NGC 1818 in the Large Magellanic Cloud, a satellite galaxy of the Milky Way, researchers at the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University in Beijing found more binary star systems toward the periphery of cluster than in the center – the opposite of what they expected. The surprising distribution of binaries is thought to result from complex interactions among stars within young clusters.

In the dynamic environment of a star cluster, high-mass stars are thought to gravitate toward the center of a cluster when they give a ‘kick’ to lower-mass stars and lose energy, explained KIAA Prof. Richard de Grijs, who led the study. This leads them to sink to the cluster center, while the lower-mass stars gain energy and might move to orbits at greater distances from the cluster core. Astronomers call this process “mass segregation.”

However, when the Kavli researchers looked closely at binary star systems within NGC 1818, they found a much more complex picture.

Full Story: http://www.kavlifoundation.org/kavli-news/KIAA-simple-view-gravity-crowded-clusters