Milky Way Radiation Reveals Itself to Distant NASA Probes (SPACE.com)

Decades after NASA's Voyager spacecraft began hurtling toward interstellar space, the twin probes are still shedding light on the universe, now by offering an unprecedented view of our own galaxy.

As they roam ever outward to the edge of the solar system, the two Voyager spacecraft are providing the first glimpse of Milky Way radiation that scientists have already seen coming from other galaxies. The data could lead to a better understanding of star formation, including the mystery surrounding the earliest stars in the universe, researchers said.

NASA launched the two Voyager spacecraft in 1977 to explore our solar system's giant planets and to study the electrically charged solar wind streaming from the sun. The probes far exceeded the expectations of mission planners, and to this day, they continue to beam back data.

The Voyagers are now providing us with the first glimpse of a critical type of ultraviolet radiation from our galaxy known as the Lyman-alpha line. This is the brightest band of light shed by hydrogen, the most abundant element in the universe.

Studying the Lyman-alpha line can offer many insights into cosmic phenomena, such as star formation, the electrically charged environments in which the atmospheres of young planets evolve, and the shocked gas in interstellar space. [Photos from NASA's Voyager 1 and 2 Probes]

Astronomers have seen Lyman-alpha rays from other galaxies, helping them peer into the universe's early history. However, we have never seen ones from our own galaxy, because our sun essentially blinds our view.

Specifically, ultraviolet rays from our sun get scattered around by hydrogen entering our solar system from interstellar space. This leads to a haze that blinds us to Lyman-alpha rays from elsewhere in our galaxy. We can detect other galaxies' Lyman-alpha rays because they have shifted into longer optical and infrared wavelengths — ones that no longer get scattered by this hydrogen — as their galaxies rush away from us. This is similar to how ambulance sirens grow lower in pitch as the vehicle drives farther away.

Now Voyager 1 and 2 are far enough away from this ultraviolet haze for them to get a clear view of the Milky Way's Lyman-alpha rays.

"It is like beginning to see small candles within a brightly lit room," study lead author Rosine Lallement, a space scientist and astronomer at the Paris Observatory in Meudon, France, told SPACE.com.

The spacecraft have confirmed that most of these newfound rays appear to come from star-forming regions, as astronomers expected. Future study of the Milky Way's Lyman-alpha rays could help us better understand those from other galaxies, researchers added.

"This radiation traces where young hot stars are being born — therefore, knowing the amount of emitted Lyman-alpha radiation from a galaxy corresponds to the rate at which stars are being born," Lallement said. "A major goal is to detect the first apparition of stars in the young universe, so detecting Lyman-alpha from the most-distant ones and correctly interpreting the signal is one of the major challenges."

Ironically, just as the Voyager probes are getting their best views of these Milky Way rays, their ability to see them is failing. Due to lack of power, the ultraviolet spectrometer on Voyager 2 has been switched off, and that same instrument on Voyager 1 could get turned off soon as well.

Still, NASA's New Horizons spacecraft, which is currently on its way to Pluto, might soon be able to monitor these rays as well.

Lallement and her colleagues detailed their findings online in the Dec. 1 issue of the journal Science.

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NASA Hopes to Launch Delayed Moon Gravity-Mapping Probes Today (SPACE.com)

After two days of delay caused by bad weather and a technical glitch, NASA is once again ready to launch two probes toward the moon to unlock the secrets of lunar gravity.

The twin Grail spacecraft are expected to launch from Florida's Cape Canaveral Air Force Station today (Sept. 10) at 8:29 a.m. EDT (1229 GMT), with a second opportunity available at 9:08 a.m. EDT (1308 GMT), if needed, NASA officials said.

The $496 million moon probes were initially slated to launch atop their unmanned Delta 2 rocket on Thursday (Sept. 8), but unacceptable high-altitude winds forced NASA to delay the liftoff.

Another chance on Friday was called off to give engineers time to assess the rocket's propulsion system after a potential glitch was detected.After a series of reviews, the team concluded that there are no issues with the rocket or its propulsion system, NASA officials said. [Photos of NASA's Grail Moon Gravity Mission]

Today's weather forecast is more optimistic, and current predictions show a 60 percent chance of acceptable conditions at the time of launch, agency officials said.

NASA has specific limits for acceptable launch weather conditions, with high winds, rain, thunder and lightning all present potential safety risks. For example, high upper level winds can affect the way rockets fly through Earth's upper atmosphere as they blast into orbit. 

The agency will closely monitor weather conditions overnight in preparation for tomorrow's attempt. The Grail mission (whose name is short for Gravity Recovery and Interior Laboratory) has a 42-day launch window that extends through Oct. 19, officials have said. [Video: Grail's Mission to Map Moon Gravity]

The twin Grail spacecraft, called Grail-A and Grail-B, will closely examine the composition of the lunar interior, and will make detailed and precise maps of the moon's gravitational field. The three-month mission is expected to help scientists solve mysteries of the moon's origin and its evolution since the natural satellite was formed 4.6 billion years ago.

Researchers are also hoping to use Grail's observations to better understand how other large, rocky bodies in the inner solar system were formed.

You can follow SPACE.com staff writer Denise Chow on Twitter @denisechow. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcomand on Facebook.

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Rover probes role water may have played on Mars

The arm of NASA's Mars Exploration Rover Opportunity is seen extended toward a light-toned rock, ''Tisdale 2'', during the 2,695th Martian day, or ''sol'', of the rover's work on Mars, in this picture taken by the rover's front hazard-avoidance camera on August 23, 2011. The rock, ''Tisdale 2'', is about 12 inches (30 cm) tall. The rover used two instruments on the robotic arm, the microscopic imager and the alpha particle X-ray spectrometer, to examine Tisdale 2. In this image, the turret at the end of the arm is positioned so that the microscopic imager is facing the rock.

Credit: Reuters/NASA/JPL-Caltech/Handout

By Irene Klotz

CAPE CANAVERAL, Florida | Fri Sep 2, 2011 8:13am EDT

CAPE CANAVERAL, Florida (Reuters) - NASA's Mars rover Opportunity is uncovering new details about the role water may have played on what is now a cold, dry planet, scientists said on Thursday.

Opportunity is one of two small rovers that landed on opposite sides of Mars in January 2004 for what were expected to be 90-day studies to look for signs of the past presence of water on the planet. Water is believed to be a key ingredient for life.

Sister probe Spirit succumbed to the harsh Martian environment last year, leaving Opportunity to go solo until the U.S. space agency's next rover, Curiosity, arrives in August 2012.

Opportunity originally touched down near the equator in an area called Meridiani Planum and almost immediately discovered evidence the plain was once covered by shallow, salty and highly acidic water. It later spent two years studying exposed bedrock and other features in a small crater named Victoria.

At a new destination, a 14-mile- (22-km) wide crater named Endeavour, Opportunity has discovered a different type of terrain with a chemical makeup unlike anything previously encountered.

"We may soon be able to study clay minerals and rock types that formed in low-acid, wet conditions, which may tell us more about a potentially habitable environment," Dave Lavery, who oversees the Mars Exploration Rovers program at NASA headquarters in Washington, told reporters during a conference call.

The first rock probed by Opportunity at Endeavour Crater shows very high levels of zinc, which on Earth is commonly found in rocks that have been exposed to hot water, such as thermal springs.

"This rock doesn't look like anything else we've ever seen before," said Cornell University planetary scientist Steve Squyres, the lead rover scientist. "We are thinking very hard over what this means."

The rock is basically basalt, a common volcanic rock, which was cemented together from fragments of other rocks shattered by an impact, for example.

"We may be dealing with a situation where water has percolated or flowed -- somehow moved through these rocks, maybe as vapor, maybe as liquid, don't know yet -- but has enhanced the zinc concentration in the rock to levels far in excess of anything that we have seen on Mars before," Squyres said.

Scientists plan to look for other zinc-rich rocks to see if the concentrations are the same, as well as probe for other minerals likewise tied to water.

Opportunity is on the hunt for bedrock, in particular, which is rock that has not been moved by impacts or other processes.

"We've got some strange stuff going on, but we're not ready to draw any firm conclusions," Squyres said.

(Editing by Tom Brown and Peter Cooney)

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Winds Delay Launch of Twin NASA Moon Probes Again (SPACE.com)

Windy weather has once again thwarted NASA's attempt to launch two gravity probes to the moon today (Sept. 10) on a mission to study the inside of the moon and its gravity field.

The two Grail spacecraft were scheduled to launch on an unmanned Delta 2 rocket from the Cape Canaveral Air Force Station in Florida this morning at 8:29 a.m. EDT (1229 GMT), but stubborn high-altitude winds – the same thing that forced NASA to stand down during initial launch attempts on Thursday (Sept. 8) – caused yet another delay.

A second opportunity to launch the Grail mission this morning is available at 9:08 a.m. EDT (1308 GMT), but if weather conditions do not improve, NASA will have to wait until tomorrow before they can try again. [Photos of NASA's Grail Moon Gravity Mission]

Another chance on Friday (Sept. 9) was called off to give engineers time to assess the rocket's propulsion system after a potential glitch was detected. After a series of reviews, the team concluded that there are no issues with the rocket or its propulsion system, NASA officials said.

The $496 million Grail mission will closely analyze the composition of the lunar interior, and the twin probes will make detailed and precise maps of the moon's gravitational field. The three-month expedition is expected to help scientists uncover clues of the moon's origin and evolution.

Grail's observations should also shed light on how other large, rocky bodies in the inner solar system were formed.

You can follow SPACE.com staff writer Denise Chow on Twitter @denisechow. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

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NASA Primes Twin Moon Gravity Probes for September Launch (SPACE.com)

Jason Rhian, SPACE.com Contributor
Space.com Jason Rhian, Space.com Contributor
space.com – 1 hr 2 mins ago

CAPE CANAVERAL, Fla. — A set of twin lunar probes are gearing up for a planned September launch to the moon,  with NASA set to attach the spacecraft duo to their rocket soon.

The twin Gravity Recovery and Interior Laboratory spacecraft (nicknamed GRAIL) are poised to launch moonward on Sept. 8 from the Cape Canaveral Air Force Base here.

The GRAIL mission is designed to discover details of the moon's gravity field from the inside out. The twin probes will fly in tandem to scan the lunar crust to the core, in hopes of collecting measurements for the most accurate gravitational map of the moon ever produced.

"Unlike many other planetary missions GRAIL consists of two spacecraft which are mirror images of one another," said Sami Asmar a member of the GRAIL science team. "So they cannot be interchanged or switched and they will fly together in formation transmitting radio information between the two spacecraft – this allows us to peer into the moon from the core to the crust." [Photos: Our Changing Moon]

Cleaning up for the moon

The GRAIL probes are currently being housed in a clean room near NASA's Kennedy Space Center here. Anyone who enters the ultra-clean facility is required to wear a protective white jumpsuit, sometimes referred to as a "bunny suit."

This head-to-toe outer layer leaves only the eyes exposed, but it is just the first precautionary tier in a multi-layered system designed to keep the spacecraft clean before it is sent to our nearest celestial neighbor.

All camera equipment brought in to photograph the twin GRAIL spacecraft must be cleaned under the supervision of specially trained contamination-control specialists, and strict rules govern what type of equipment can be brought into the facility. These regulations extend even to pens and paper — no conventional writing utensils are allowed inside the clean room, since ordinary paper can carry particles that could clog vital systems on the spacecraft in the microgravity environment of space.

Shoot for the moon

Grail is slated to launch from Launch Complex 17-B at Cape Canaveral Air Force Station on Sept. 8 at 8:37 a.m. EDT (1237 GMT). The two probes will ride on a Delta 2 rocket, in what will be the final launch of a Delta 2 from the Air Force-run spaceport.

After the probes lift off, the journey to the moon will last about 3 1/2 months. After that, the science mission is set to last for a total of 90 days. GRAIL is similar to the Gravity Recovery and Climate Experiment or GRACE mission which launched in 2002 and made detailed measurements of Earth's gravity field. [Infographic: Inside Earth's Moon]

 "GRAIL will have a trans-lunar cruise of about three-and-a-half months, they will arrive at the moon on New Year’s Eve 2012," said Bruce Reid, the mission's launch service provider manager.  "Once there they will completely map the gravity of the moon. This is important for not only future missions, but to also provide us with a better understanding other terrestrial planets.”

The GRAIL science team is made up of a number of scientists, including former NASA astronaut Sally Ride, who is assisting with the project’s public outreach efforts.

GRAIL is the second of three NASA missions launching over the next few months to explore the solar system.

On Aug. 5, NASA launched the Juno spacecraft toward Jupiter. It will take the probe five years to reach the gas giant planet.

NASA's newest Mars rover, the Mars Science Laboratory Curiosity, is currently scheduled to launch in late November.

Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

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