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Archive for February 27, 2012

NASA Lunar Scientists Shed Light on Moon’s Impact History

February 27, 2012 Leave a comment

A team of researchers from the NASA Lunar Science Institute (NLSI) at NASA Ames Research Center, Moffett Field, Calif., have discovered that debris that caused a “lunar cataclysm” on the moon 4 billion years ago struck it at much higher speeds than those that made the most ancient craters. The scientists found evidence supporting this scenario by examining the history of crater formation on the moon.

During Earth’s earliest days, our planet and others in the inner solar system, including the moon, experienced repeated impacts from debris that formed the building blocks of the planets. Over time, as material was swept up and incorporated into the inner planets, the rate of impacts decreased. Then, roughly 4 billion years ago, a second wave of impacts appears to have taken place, with lunar projectiles hitting at much higher speeds. This increase could reflect the origin of the debris, where main belt asteroids were dislodged and sent into the inner solar system by shifts in the orbits of the giant planets.

Full Story: http://www.nasa.gov/centers/ames/news/releases/2012/12-19AR.html

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Ultra-fast Outflows Help Monster Black Holes Shape Their Galaxies

February 27, 2012 Leave a comment

A curious correlation between the mass of a galaxy’s central black hole and the velocity of stars in a vast, roughly spherical structure known as its bulge has puzzled astronomers for years. An international team led by Francesco Tombesi at NASA’s Goddard Space Flight Center in Greenbelt, Md., now has identified a new type of black-hole-driven outflow that appears to be both powerful enough and common enough to explain this link.

Most big galaxies contain a central black hole weighing millions of times the sun’s mass, but galaxies hosting more massive black holes also possess bulges that contain, on average, faster-moving stars. This link suggested some sort of feedback mechanism between a galaxy’s black hole and its star-formation processes. Yet there was no adequate explanation for how a monster black hole’s activity, which strongly affects a region several times larger than our solar system, could influence a galaxy’s bulge, which encompasses regions roughly a million times larger.

“This was a real conundrum. Everything was pointing to supermassive black holes as somehow driving this connection, but only now are we beginning to understand how they do it,” Tombesi said.

Full Story: http://www.nasa.gov/topics/universe/features/fast-outflow.html

NASA Glenn Event to Celebrate John Glenn’s Legacy on March 2

February 27, 2012 Leave a comment

NASA’s Glenn Research Center will host an event on March 2 to commemorate the 50th anniversary of John Glenn’s orbital flight, the first by an American.

“Celebrating John Glenn’s Legacy: 50 Years of Americans in Orbit” will be held at 1 p.m. EST at Cleveland State University’s Wolstein Center, 2000 Prospect Ave., in Cleveland. More than 800 complimentary tickets are being distributed to the general public for this event through a lottery by Cleveland State University in partnership with NASA Glenn.

NASA Administrator Charles Bolden and Glenn Director Ramon “Ray” Lugo will provide remarks during the one-hour program, which will include a welcome from Cleveland State University President Dr. Ronald Berkman. Space shuttle mission STS-95 pilot Steve Lindsey will pay tribute from the astronaut corps to Glenn. The program will culminate with a keynote address by the guest of honor Sen. John H. Glenn Jr.

Full Story: http://www.nasa.gov/home/hqnews/2012/feb/HQ_12-061_Glenn_50.html

Dwarf Galaxy Questions Galaxy Formation Models

February 27, 2012 Leave a comment

Researcher from the Centro de Astrofísica da Universidade do Porto (Center for Astrophysics of the University of Porto) observed the dwarf galaxy I Zw 18, and found that much of what is known about galaxy formation and evolution might need substantial revision.

CAUP Astronomer Polychronis Papaderos, along with his colleague Göran Östlin (Oskar Klein Center, U. Stokholm), used the Hubble Space Telescope (HST) to get extremely accurate observations of the I Zw 18 galaxy. Their research led to the conclusion that this enigmatic blue compact dwarf might force astronomers to review current galaxy formation models.

I Zw 18 is one of the most studied dwarf galaxies, because among those that have strong star forming activity, it’s one of the poorest in heavy elements. Besides, it’s proximity to the Earth, combined with a total exposure time of nearly 3 days, gave the researchers data with unprecedented resolution and sensitivity.

Full Story: http://www.alphagalileo.org/ViewItem.aspx?ItemId=117893&CultureCode=en

Supernova Fireworks

February 27, 2012 Leave a comment

A little luck and a lot of hard work can really light up the sky.

Taking advantage of a little-known feature of the Sloan Digital Sky Survey, a team of astronomers led by Carles Badenes of the University of Pittsburgh has helped to clarify the origins of an important type of exploding star—using nothing but a few thousand small, faint stars in our own cosmic backyard.

The astronomical fireworks the team studied are so-called “Type Ia supernovae,” exploding stars so incredibly bright that we can see them even in the most distant galaxies. In a paper published today on the arXiv preprint server, Badenes and colleagues compared the number of these supernovae in distant galaxies to the number of binary white dwarfs in our galaxy. The rate is similar, suggesting that merging white dwarfs are indeed a reasonable explanation for these giant explosions.

Full Story: http://www.sdss3.org/press/20120227.fireworks.php

Rapid Expansion or Something Weird in the Early Universe

February 27, 2012 Leave a comment

The widely-accepted theory of cosmic inflation states that our universe expanded rapidly in the moments after its birth, resulting in the immense expanse we see today.

Cosmic inflation explains why the universe is billions of years old, as well as why the universe is nearly flat. The theory’s conclusions about how the universe should look match observations by NASA’s Wilkinson Microwave Anisotropy Probe (WMAP).

But is inflation the only model that can explain the beginnings of the universe?

That’s the question that University at Buffalo physicists Ghazal Geshnizjani, Will Kinney and Azadeh Moradinezhad Dizgah set out to answer with their study, “General Conditions for Scale-Invariant Perturbations in an Expanding Universe.”

Full Story: http://www.buffalo.edu/news/13219

NASA Official Announces Chair of New Mars Program Planning Group

February 27, 2012 Leave a comment

NASA’ s associate administrator for the Science Mission Directorate, John Grunsfeld, has named former veteran NASA program manager Orlando Figueroa to lead a newly established Mars Program Planning Group (MPPG) tasked to reformulate the agency’s Mars Exploration Program. Figueroa’s first assignment is to develop a draft framework for review by March 15.

Grunsfeld made the announcement at an annual gathering of Mars scientists and engineers in Dulles, Va. Figueroa, a consultant with more than 30 years of aerospace experience, will lead the scientific and technical team to develop an integrated strategy for NASA’s Mars Exploration Program in light of current funding constraints. The team’s initial focus will be on a possible 2018-2020 robotic mission. The program’s official framework will be developed in consultation with the science community and international partners and is expected to be released for full review as early as this summer.

Full Story: http://www.nasa.gov/home/hqnews/2012/feb/HQ_12-060_Mars_Program_Planning_Group.html