SpaceJibe

October 29, 2009

Violent Star Explosion Breaks Records

Filed under: Black Holes, Cosmology, Gamma Ray Bursts, Supernova — bferrari @ 1:20 pm

Biggest explosion in the Universe...ever!

Light from a star that exploded 13 billion years ago has been detected, becoming the most distant object in the universe ever observed.

The light from the distant explosion, called a gamma-ray burst, first reached Earth on April 23 and was detected by NASA’s Swift satellite. Gamma-ray bursts are thought to be associated with the formation of star-sized black holes as massive stars collapse.

Within hours, telescopes around the world were turned on the burst — the most violent explosions in the universe — observing its fading afterglow to glean clues about its source and location.

Two teams, one using the European Southern Observatory’s 8.2-meter Very Large Telescope, located in La Silla, Chile, and the other using the 3.6-meter Italian Telescopio Nazionale Galileo in Spain, pinpointed the distance to the blast, dubbed GRB 090423, at more than 13 billion light-years from Earth. (The previous record holder, GRB 080913, was 12.8 billion light-years distant.)

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This enormous distance means that the gamma-ray burst occurred just 630 million years after the theoretical Big Bang, when the universe was only four percent of its current age.

‘Spine-tingling’ discovery

In recent years, astronomers have been detecting gamma-ray bursts, galaxies and quasars at ever farther distances, closer to the birth of the universe’s first stars and galaxies. So it was only a matter of time before they detected such an early explosion, said Nial Tanvir of the University of Leicester in the U.K. Tanvir worked on the ESO team.

“We have been looking for a burst like this for several years, so we of course expected that we’d get lucky one day — but it was a “spine-tingling” moment to realize that this was finally it,” Tanvir told SPACE.com.

Astronomers hope that observations of this and other gamma-ray bursts just as far away (and thought to represent some of the earliest stellar populations) will shed light on the so-called “cosmic dark ages,” a time before the first stars and galaxies ignited.

“This explosion provides an unprecedented look at an era when the universe was very young and also was undergoing drastic changes,” said Dale Frail of the National Radio Astronomy Observatory. “The primal cosmic darkness was being pierced by the light of the first stars and the first galaxies were beginning to form. The star that exploded in this event was a member of one of these earliest generations of stars.”

Cosmic dark ages

After the Big Bang, the universe had cool rapidly as it expanded. About 400,000 years later, free electrons and protons (negative and positive charges, respectively) combined to form neutral atoms, leaving the universe awash in a background radiation that we currently can detect in the microwave part of the electromagnetic spectrum (the so-called Cosmic Microwave Background).

The universe stayed in this neutral stage until the first stars and galaxies light it up. The photons from these stars knocked electrons free from the atoms, “re-ionizing” the universe. But detecting the most distant galaxies and quasars from this period is difficult, and so astronomers are hoping that distant gamma-ray bursts such as GRB 090423 will give them information about this re-ionization period.

It will likely take many more gamma-ray bursts to say anything definitive about this cosmic dark age though.

At present, we have only a few observations from these early epochs. Thus, even a single, new data may provide useful constrain to our models of the early Universe. However, to be frank, a decisive step forward for our knowledge of this period of the Universe’s history requires the collection of a relatively large sample of distant [gamma-ray bursts],” Ruben Salvaterra of the National Institute of Astrophysics in Italy told SPACE.com. Salvaterra worked on the Italian Telescopio Nazionale Galileo team.

Both team’s observations are detailed in the Oct. 29 issue of the journal Nature.

Asked how long he thought this distance record would hold, Tanvir replied, “Based on past experience, it could certainly be a few years before it’s broken, but it wouldn’t entirely surprise me if it was tomorrow.” He said he did expect the next record holder to be another gamma-ray burst.

Source

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October 22, 2009

Mum’s the Word for NASA’s Secret Space Plane X-37B

Filed under: Gadgets, Space Exploration, Wierd — bferrari @ 11:48 am
Artist concept of the X-37 advanced technology flight demonstrator re-entering Earths atmosphere. (NASA)

Artist concept of the X-37 advanced technology flight demonstrator re-entering Earth's atmosphere. (NASA)

You would think that an unpiloted space plane built to rocket spaceward from Florida atop an Atlas booster, circle the planet for an extended time, then land on autopilot on a California runway would be big news. But for the U.S. Air Force X-37B project — seemingly, mum’s the word.

There is an air of vagueness regarding next year’s Atlas Evolved Expendable launch of the unpiloted, reusable military space plane. The X-37B will be cocooned within the Atlas rocket’s launch shroud — a ride that’s far from cheap.

SLIDESHOW: A Glimpse at NASA’s Secret Plane

While the launch range approval is still forthcoming, SPACE.com has learned that the U.S. Air Force has the X-37B manifested for an April 2010 liftoff.

As a mini-space plane, this Boeing Phantom Works craft has been under development for years. Several agencies have been involved in the effort, NASA as well as the Defense Advanced Projects Research Agency (DARPA) and various arms of the U.S. Air Force.

Over the last few months, I’ve been in touch with DARPA, Boeing, the Pentagon, the U.S. Air Force Space Command, as well as NASA itself. Either you get a “not in our portfolio” or are given a “go to” pass to another agency. Just a few weeks ago, I even commandeered a face-to-face “no comment” from a top Pentagon official for Air Force space programs about X-37B.

Tight-lipped factor

The tight-lipped factor surrounding the space plane, its mission, and who is in charge is curious. Such a hush-hush factor seems to mimic in pattern that mystery communications spacecraft lofted last month aboard an Atlas 5 rocket, simply called PAN. Its assignment and what agency owns it remains undisclosed.

But in a brief burst of light eking from the new era of government transparency, I did score this comment from NASA.

While the program is now under the U.S. Air Force, NASA is looking forward to receiving data from the advanced technology work.

“NASA has a long history of involvement with the X-37 program. We continue to monitor and share information on technology developments,” said Gary Wentz, chief engineer Science and Missions Systems Office at the NASA Marshall Space Flight Center. “We are looking forward to a successful first flight and to receiving data from some advanced technologies of interest to us, such as thermal protection systems, guidance, navigation and control, and materials for autonomous re-entry and landing.”

Full NASA Coverage on FoxNews.com

The vehicle itself is about 29 feet long with a roughly 15-foot wingspan and weighs in at over five tons at liftoff. Speeding down from space, the craft would likely make use of Runway 12/30 — 15,000 feet long by 200 feet wide — at Vandenberg Air Force Base in California.

Vandenberg serves as an emergency space shuttle landing strip, as a second backup after California’s Edwards Air Force Base – which has also been noted as a landing spot for the X-37B.

Once in orbit, what such a vehicle might enable depends on the eye of the beholder. Intelligence gathering, kicking off small satellites, testing space gear are feasible duties, as is developing reusable space vehicle technologies.


Space test platform

Just last month, a U.S. Air Force fact sheet noted that the Air Force Rapid Capabilities Office (RCO), located in Washington, D.C. “is working on the X-37B Orbital Test Vehicle to demonstrate a reliable, reusable, unmanned space test platform for the United States Air Force.”

The mission of the RCO is to expedite development and fielding of select Department of Defense combat support and weapon systems by leveraging defense-wide technology development efforts and existing operational capabilities.

“The problem with it [X37-B] is whether you see it as a weapons platform,” said Theresa Hitchens, former head of the Center for Defense Information’s Space Security Program, now Director of the United Nations Institute for Disarmament Research (UNIDIR) in Geneva, Switzerland.

“It then becomes, if I am not mistaken, a Global Strike platform. There are a lot of reasons to be concerned about Global Strike as a concept,” Hitchens told SPACE.com.

The implications of the program as a possible space weapon are surely not lost on potential U.S. competitors, Hitchens said, who may well see anti-satellites (ASATs) as a leveler.

“Would this thing be vulnerable to ASATs? Yes, if it stayed on orbit any length of time,” Hitchens added. “While I see value of such a platform as a pop-up reconnaissance or even communications platform, if weaponized it becomes yet another reason for other nations to consider building dangerous ASATs,” she cautioned.

Another mission question is, to what extent the X-37B might play into the recent announcement that NASA is partnering with the U.S. Air Force Research Laboratory to develop a technology roadmap for the commercial reusable launch vehicle, or RLV, industry.

All that said, and after years in the making, the X-37B is approaching its first globe-trotting, milestone making and historic flight – that much is known.

Source

October 7, 2009

Phew! NASA Downgrades Asteroid-Strike Threat

Filed under: Asteroids, Inner Solar System, Near Earth Objects (NEOs) — bferrari @ 2:35 pm

LOS ANGELES — NASA says the chances of an 885-foot (270-meter) asteroid striking Earth in 2036 have been downgraded.

Scientists initially believed there was a 1-in-45,000 chance that Apophis could hit the planet on April 13, 2036. But NASA said Wednesday the threat has been dropped to 1-in-250,000 after it recalculated the asteriod’s path.

Earth got a scare in 2004, when initial readings suggested the newly discovered Apophis seemed to have a chance of hitting in 2029. Further observations ruled out any possibility of an impact.

Apophis is scheduled to make a close but harmless approach in 2029.

Source

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