Nasa Technology News

As most of Texas continues to experience the worst one-year drought on record, more than 170 wildfires have erupted across the Lone Star State so far this month alone. The Texas Forest Service reports the past week's blazes have charred more than 135,000 acres and destroyed more than 1,000 homes.

Strong, gusty winds on the western side of Tropical Storm Lee, which passed over Louisiana on Monday, Sept. 5, 2011, stoked the fires burning throughout eastern Texas. The Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra spacecraft passed over the wildfires at 12:05 p.m. CDT on Sept. 5. At that time, temperatures were around 80 degrees Fahrenheit (27 degrees Celsius), with winds from the north gusting to 25 mph (40 kilometers per hour).

This image is a blend of data from MISR's vertical-viewing camera, which provides the sharpest view of surface features, and data acquired at a view angle of 70 degrees, which accentuates the appearance of smoke plumes generated by the fires. The Bear Creek Fire north of Marshall, near the top center of the image, is the largest fire in the image. When this image was acquired, the fire had charred 30,000 acres and was 0 percent contained. To the west is the Diana Fire, just north of Longview, and the Henderson-502 Fire, northwest of Nacogdoches.

The combined smoke from these two fires extends more than 171 miles (275 kilometers), passing over Lake Livingston into the northern outskirts of Houston. The city of Houston appears as the grayish area at the bottom of the image, to the left of Galveston Bay and the Gulf of Mexico.

This image covers about 275 miles (442 kilometers) in the north-south direction, and 199 miles (320 kilometers) in the east-west direction.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed by NASA's Goddard Space Flight Center, Greenbelt, Md. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center. JPL is a division of the California Institute of Technology.

NASA has selected three proposals, including one from NASA's Jet Propulsion Laboratory in Pasadena, Calif., as Technology Demonstration Missions to transform space communications, deep space navigation and in-space propulsion capabilities. The projects will develop and fly a space solar sail, deep space atomic clock, and space-based optical communications system.

These crosscutting flight demonstrations were selected because of their potential to provide tangible, near-term products and infuse high-impact capabilities into NASA's future space operations missions. By investing in high payoff, disruptive technology that industry does not have today, NASA matures the technology required for its future missions while proving the capabilities and lowering the cost of government and commercial space activities.

"These technology demonstration missions will improve our communications, navigation and in-space propulsion capabilities, enable future missions that could not otherwise be performed, and build the technological capability of America's space industry," said NASA Chief Technologist Bobby Braun at NASA Headquarters in Washington. "Optical communication will enable rapid return of the voluminous data associated with sending spacecraft and humans to new frontiers. High-performance atomic clocks enable a level of spacecraft navigation precision and autonomous operations in deep space never before achieved, and solar sails enable new space missions through highly efficient station-keeping or propellant-less main propulsion capabilities for spacecraft."

The proposals selected for demonstration missions are:
-- Laser Communications Relay Demonstration, David J. Israel, principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Md.
-- Deep Space Atomic Clock, Todd Ely, principal investigator at the California Institute of Technology/NASA's Jet Propulsion Laboratory in Pasadena, Calif.
-- Beyond the Plum Brook Chamber; An In-Space Demonstration of a Mission-Capable Solar Sail, Nathan Barnes, principal investigator at L'Garde Inc., of Tustin, Calif.

Technology Demonstration Missions are a vital element in NASA's space technology maturation pipeline. They prove feasibility in the environment of space and help advance innovations from concept to flight and use in missions. The advances anticipated from communications, navigation and in-space propulsion technology will allow future NASA missions to pursue bolder and more sophisticated science, enable human missions beyond low Earth orbit, and enable entirely new approaches to U.S. space operations.

The Laser Communications Relay demonstration mission will fly and validate a reliable, capable, and cost-effective optical communications technology. Optical communications technology provides data rates up to 100 times higher than today's systems, which will be needed for future human and robotic space missions. The technology is directly applicable to the next generation of NASA's space communications network. After the demonstration, the developed space and ground assets will be qualified for use by near-Earth and deep space missions requiring high bandwidth and a small ground station reception area.

The Deep Space Atomic Clock demonstration mission will fly and validate a miniaturized mercury-ion atomic clock that is 10-times more accurate than today's systems. This project will demonstrate ultra-precision timing in space and its benefits for one-way radio navigation. The investigation will fly as a hosted payload on an Iridium spacecraft and make use of GPS signals to demonstrate precision orbit determination and confirm the clock's performance. Precision timing and navigation is critical to the performance of a wide range of deep space exploration missions.

The Solar Sail demonstration mission will deploy and operate a sail area 7 times larger than ever flown in space. It is potentially applicable to a wide range of future space missions, including an advanced space weather warning system to provide more timely and accurate notice of solar flare activity. This technology also could be applied to economical orbital debris removal and propellant-less deep space exploration missions. The National Oceanic and Atmospheric Administration is collaborating with NASA and L'Garde Inc. on the demonstration.

The clock and solar sail will be ready for flight in three years. The optical communications team anticipates it will take four years to mature the technology for flight. NASA's Office of the Chief Technologist plans to make a total investment in these three missions of approximately $175 million, contingent on future appropriations. Each of the selected teams also will receive funding from partners who plan on using the technologies as part of future space missions.

Projects include all elements of the flight test demonstration including test planning, flight hardware, launch, ground operations, and post-testing assessment and reporting. Each team has proposed between one and two years of spaceflight operations and data analysis. To reduce cost, the technology demonstrations will ride to space with other payloads aboard commercially provided launch vehicles. Launches are anticipated in 2015 and 2016.

A NASA-led research team has confirmed what Walt Disney told us all along: Earth really is a small world, after all.

Since Charles Darwin's time, scientists have speculated that the solid Earth might be expanding or contracting. That was the prevailing belief, until scientists developed the theory of plate tectonics, which explained the large-scale motions of Earth's lithosphere, or outermost shell. Even with the acceptance of plate tectonics half a century ago, some Earth and space scientists have continued to speculate on Earth's possible expansion or contraction on various scientific grounds.

Now a new NASA study, published recently in Geophysical Research Letters, has essentially laid those speculations to rest. Using a cadre of space measurement tools and a new data calculation technique, the team detected no statistically significant expansion of the solid Earth.

So why should we care if Mother Nature is growing? After all, Earth's shape is constantly changing. Tectonic forces such as earthquakes and volcanoes push mountains higher, while erosion and landslides wear them down. In addition, large-scale climate events like El Nino and La Nina redistribute vast water masses among Earth's ocean, atmosphere and land.

Scientists care because, to put movements of Earth's crust into proper context, they need a frame of reference to evaluate them against. Any significant change in Earth's radius will alter our understanding of our planet's physical processes and is fundamental to the branch of science called geodesy, which seeks to measure Earth's shape and gravity field, and how they change over time.

To make these measurements, the global science community established the International Terrestrial Reference Frame. This reference frame is used for ground navigation and for tracking spacecraft in Earth orbit. It is also used to monitor many aspects of global climate change, including sea level rise and its sources; imbalances in ice mass at Earth's poles; and the continuing rebound of Earth's surface following the retreat of the massive ice sheets that blanketed much of Earth during the last Ice Age.

NASA's solar-powered Juno spacecraft lifted off from Cape Canaveral Air Force Station in Florida at 9:25 a.m. PDT (12:25 p.m. EDT) Friday to begin a five-year journey to Jupiter.

Juno's detailed study of the largest planet in our solar system will help reveal Jupiter's origin and evolution. As the archetype of giant gas planets, Jupiter can help scientists understand the origin of our solar system and learn more about planetary systems around other stars.

"Today, with the launch of the Juno spacecraft, NASA began a journey to yet another new frontier," NASA Administrator Charles Bolden said. "The future of exploration includes cutting-edge science like this to help us better understand our solar system and an ever-increasing array of challenging destinations."

After Juno's launch aboard an Atlas V rocket, mission controllers now await telemetry from the spacecraft indicating it has achieved its proper orientation, and that its massive solar arrays, the biggest on any NASA deep-space probe, have deployed and are generating power.

"We are on our way, and early indications show we are on our planned trajectory," said Jan Chodas, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We will know more about Juno's status in a couple hours after its radios are energized and the signal is acquired by the Deep Space Network antennas at Canberra."

Juno will cover the distance from Earth to the moon (about 250,000 miles or 402,336 kilometers) in less than one day's time. It will take another five years and 1,740 million miles (2,800 million kilometers) to complete the journey to Jupiter. The spacecraft will orbit the planet's poles 33 times and use its collection of eight science instruments to probe beneath the gas giant's obscuring cloud cover to learn more about its origins, structure, atmosphere and magnetosphere, and look for a potential solid planetary core.

With four large moons and many smaller moons, Jupiter forms its own miniature solar system. Its composition resembles that of a star, and if it had been about 80 times more massive, the planet could have become a star instead.

"Jupiter is the Rosetta Stone of our solar system," said Scott Bolton, Juno's principal investigator from the Southwest Research Institute in San Antonio. "It is by far the oldest planet, contains more material than all the other planets, asteroids and comets combined, and carries deep inside it the story of not only the solar system but of us. Juno is going there as our emissary -- to interpret what Jupiter has to say."

Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife, the goddess Juno, was able to peer through the clouds and reveal Jupiter's true nature.

The NASA Deep Space Network -- or DSN -- is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions.

JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, built the spacecraft. Launch management for the mission is the responsibility of NASA's Launch Services Program at the Kennedy Space Center in Florida. JPL is a division of the California Institute of Technology in Pasadena.

For more information about Juno, visit http://www.nasa.gov/juno and http://missionjuno.swri.edu .

Galaxies once thought of as voracious tigers are more like grazing cows, according to a new study using NASA's Spitzer Space Telescope.

Astronomers have discovered that galaxies in the distant, early universe continuously ingested their star-making fuel over long periods of time. This goes against previous theories that the galaxies devoured their fuel in quick bursts after run-ins with other galaxies.

"Our study shows the merging of massive galaxies was not the dominant method of galaxy growth in the distant universe," said Ranga-Ram Chary of NASA's Spitzer Science Center at the California Institute of Technology in Pasadena, Calif. "We're finding this type of galactic cannibalism was rare. Instead, we are seeing evidence for a mechanism of galaxy growth in which a typical galaxy fed itself through a steady stream of gas, making stars at a much faster rate than previously thought."

Chary is the principal investigator of the research, appearing in the Aug. 1 issue of the Astrophysical Journal. According to his findings, these grazing galaxies fed steadily over periods of hundreds of millions of years and created an unusual amount of plump stars, up to 100 times the mass of our sun.

"This is the first time that we have identified galaxies that supersized themselves by grazing," said Hyunjin Shim, also of the Spitzer Science Center and lead author of the paper. "They have many more massive stars than our Milky Way galaxy."

Galaxies like our Milky Way are giant collections of stars, gas and dust. They grow in size by feeding off gas and converting it to new stars. A long-standing question in astronomy is: Where did distant galaxies that formed billions of years ago acquire this stellar fuel? The most favored theory was that galaxies grew by merging with other galaxies, feeding off gas stirred up in the collisions.

Chary and his team addressed this question by using Spitzer to survey more than 70 remote galaxies that existed 1 to 2 billion years after the Big Bang (our universe is approximately 13.7 billion years old). To their surprise, these galaxies were blazing with what is called H alpha, which is radiation from hydrogen gas that has been hit with ultraviolet light from stars. High levels of H alpha indicate stars are forming vigorously. Seventy percent of the surveyed galaxies show strong signs of H alpha. By contrast, only 0.1 percent of galaxies in our local universe possess this signature.

Previous studies using ultraviolet-light telescopes found about six times less star formation than Spitzer, which sees infrared light. Scientists think this may be due to large amounts of obscuring dust, through which infrared light can sneak. Spitzer opened a new window onto the galaxies by taking very long-exposure infrared images of a patch of sky called the GOODS fields, for Great Observatories Origins Deep Survey.

Further analyses showed that these galaxies furiously formed stars up to 100 times faster than the current star-formation rate of our Milky Way. What's more, the star formation took place over a long period of time, hundreds of millions of years. This tells astronomers that the galaxies did not grow due to mergers, or collisions, which happen on shorter timescales. While such smash-ups are common in the universe -- for example, our Milky Way will merge with the Andromeda galaxy in about 5 billion years -- the new study shows that large mergers were not the main cause of galaxy growth. Instead, the results show that distant, giant galaxies bulked up by feeding off a steady supply of gas that probably streamed in from filaments of dark matter.

Chary said, "If you could visit a planet in one of these galaxies, the sky would be a crazy place, with tons of bright stars, and fairly frequent supernova explosions."

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer Space Telescope mission for the agency's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech. Caltech manages JPL for NASA.

Since 1611, humans have recorded the comings and goings of black spots on the sun. The number of these sunspots waxes and wanes over approximately an 11-year cycle -- more sunspots generally mean more activity and eruptions on the sun and vice versa. The number of sunspots can change from cycle to cycle, and 2008 saw the longest and weakest solar minimum since scientists have been monitoring the sun with space-based instruments.

Observations have shown, however, that magnetic effects on Earth due to the sun, effects that cause the aurora to appear, did not go down in synch with the cycle of low magnetism on the sun. Now, a paper in Annales Geophysicae that appeared on May 16, 2011 reports that these effects on Earth did in fact reach a minimum -- indeed they attained their lowest levels of the century -- but some eight months later. The scientists believe that factors in the speed of the solar wind, and the strength and direction of the magnetic fields embedded within it, helped produce this anomalous low.

"Historically, the solar minimum is defined by sunspot number," says space weather scientist Bruce Tsurutani at NASA's Jet Propulsion Laboratory in Pasadena, Calif., who is first author on the paper. "Based on that, 2008 was identified as the period of solar minimum. But the geomagnetic effects on Earth reached their minimum quite some time later, in 2009. So we decided to look at what caused the geomagnetic minimum."

Geomagnetic effects basically amount to any magnetic changes on Earth due to the sun, and they're measured by magnetometer readings on the surface of the Earth. Such effects are usually harmless, with the only obvious sign of their presence being the appearance of auroras near the poles. However, in extreme cases, they can cause power grid failures on Earth or induce dangerous currents in long pipelines, so it is valuable to know how the geomagnetic effects vary with the sun.

Three things help determine how much energy from the sun is transferred to Earth's magnetosphere from the solar wind: the speed of the solar wind, the strength of the magnetic field outside Earth's bounds (known as the interplanetary magnetic field) and which direction it is pointing, since a large southward component is necessary to connect successfully to Earth's magnetosphere and transfer energy. The team -- which also included Walter Gonzalez and Ezequiel Echer of the Brazilian National Institute for Space Research in São José dos Campos, Brazil -- examined each component in turn.

First, the researchers noted that in 2008 and 2009, the interplanetary magnetic field was the lowest it had been in the history of the space age. This was an obvious contribution to the geomagnetic minimum. But since the geomagnetic effects didn't drop in 2008, it could not be the only factor.

To examine the speed of the solar wind, they turned to NASA's Advanced Composition Explorer (ACE), which is in interplanetary space outside the Earth's magnetosphere, approximately 1 million miles toward the sun. The ACE data showed that the speed of the solar wind stayed high during the sunspot minimum. Only later did it begin a steady decline, correlating to the timing of the decline in geomagnetic effects.

The next step was to understand what caused this decrease. The team found a culprit in something called coronal holes. Coronal holes are darker, colder areas within the sun's outer atmosphere. Fast solar wind shoots out the center of coronal holes at speeds up to 500 miles per second, but wind flowing out of the sides slows down as it expands into space.

"Usually, at solar minimum, the coronal holes are at the sun's poles," says Giuliana de Toma, a solar scientist at the National Center for Atmospheric Research whose research on this topic helped provide insight for this paper. "Therefore, Earth receives wind from only the edges of these holes, and it's not very fast. But in 2007 and 2008, the coronal holes were not confined to the poles as normal."

Those coronal holes lingered at low latitudes to the end of 2008. Consequently, the center of the holes stayed firmly pointed towards Earth, sending fast solar wind in Earth's direction. Only as they finally appeared closer to the poles in 2009 did the speed of the solar wind at Earth begin to slow down. And, of course, the geomagnetic effects and sightings of the aurora along with it.

Coronal holes seem to be responsible for minimizing the southward direction of the interplanetary magnetic field as well. The solar wind's magnetic fields oscillate on the journey from the sun to Earth. These fluctuations are known as Alfvén waves. The wind coming out of the centers of the coronal holes has large fluctuations, meaning that the southward magnetic component – like that in all the directions -- is fairly large. The wind that comes from the edges, however, has smaller fluctuations, and comparably smaller southward components. So, once again, coronal holes at lower latitudes would have a better chance of connecting with Earth's magnetosphere and causing geomagnetic effects, while mid-latitude holes would be less effective.

Working together, these three factors -- low interplanetary magnetic field strength, combined with slower solar wind speed and smaller magnetic fluctuations due to coronal hole placement -- create the perfect environment for a geomagnetic minimum.

Knowing what situations cause and suppress intense geomagnetic activity on Earth is a step toward better predicting when such events might happen. To do so well, Tsurutani points out, requires focusing on the tight connection between such effects and the complex physics of the sun. "It's important to understand all of these features better," he says. "To understand what causes low interplanetary magnetic fields and what causes coronal holes in general. This is all part of the solar cycle. And all part of what causes effects on Earth."

More than 30 years after they left Earth, NASA's twin Voyager probes are now at the edge of the solar system. Not only that, they're still working. And with each passing day they are beaming back a message that, to scientists, is both unsettling and thrilling.

The message is, "Expect the unexpected."

"It's uncanny," says Ed Stone of the California Institute of Technology in Pasadena, Voyager Project Scientist since 1972. "Voyager 1 and 2 have a knack for making discoveries."
Today, April 28, 2011, NASA held a live briefing to reflect on what the Voyager mission has accomplished--and to preview what lies ahead as the probes prepare to enter the realm of interstellar space in our Milky Way galaxy.

The adventure began in the late 1970s when the probes took advantage of a rare alignment of outer planets for an unprecedented Grand Tour. Voyager 1 visited Jupiter and Saturn, while Voyager 2 flew past Jupiter, Saturn, Uranus and Neptune. (Voyager 2 is still the only probe to visit Uranus and Neptune.)

When pressed to name the top discoveries from those encounters, Stone pauses, not for lack of material, but rather an embarrassment of riches. "It's so hard to choose," he says.

Stone's partial list includes the discovery of volcanoes on Jupiter's moon Io; evidence for an ocean beneath the icy surface of Europa; hints of methane rain on Saturn's moon Titan; the crazily-tipped magnetic poles of Uranus and Neptune; icy geysers on Neptune's moon Triton; planetary winds that blow faster and faster with increasing distance from the sun.

"Each of these discoveries changed the way we thought of other worlds," says Stone.

In 1980, Voyager 1 used the gravity of Saturn to fling itself slingshot-style out of the plane of the solar system. In 1989, Voyager 2 got a similar assist from Neptune. Both probes set sail into the void.

Sailing into the void sounds like a quiet time, but the discoveries have continued.

Stone sets the stage by directing our attention to the kitchen sink. "Turn on the faucet," he instructs. "Where the water hits the sink, that's the sun, and the thin sheet of water flowing radially away from that point is the solar wind. Note how the sun 'blows a bubble' around itself."

There really is such a bubble, researchers call it the "heliosphere," and it is gargantuan. Made of solar plasma and magnetic fields, the heliosphere is about three times wider than the orbit of Pluto. Every planet, asteroid, spacecraft, and life form belonging to our solar system lies inside.

The Voyagers are trying to get out, but they're not there yet. To locate them, Stone peers back into the sink: "As the water [or solar wind] expands, it gets thinner and thinner, and it can't push as hard. Abruptly, a sluggish, turbulent ring forms. That outer ring is the heliosheath--and that is where the Voyagers are now."

The heliosheath is a very strange place, filled with a magnetic froth no spacecraft has ever encountered before, echoing with low-frequency radio bursts heard only in the outer reaches of the solar system, so far from home that the sun is a mere pinprick of light.

"In many ways, the heliosheath is not like our models predicted," says Stone.

In June 2010, Voyager 1 beamed back a startling number: zero. That's the outward velocity of the solar wind where the probe is now. No one thinks the solar wind has completely stopped; it may have just turned a corner. But which way? Voyager 1 is trying to figure that out through a series of "weather vane" maneuvers, in which the spacecraft turns itself in a different direction to track the local breeze. The old spacecraft still has some moves left, it seems.

No one knows exactly how many more miles the Voyagers must travel before they "pop free" into interstellar space. Most researchers believe, however, that the end is near. "The heliosheath is 3 to 4 billion miles in thickness," estimates Stone. "That means we'll be out within five years or so."

There is plenty of power for the rest of the journey. Both Voyagers are energized by the radioactive decay of a Plutonium 238 heat source. This should keep critical subsystems running through at least 2020.

After that, he says, "Voyager will become our silent ambassador to the stars."

Each probe is famously equipped with a Golden Record, literally, a gold-coated copper phonograph record. It contains 118 photographs of Earth; 90 minutes of the world's greatest music; an audio essay entitled Sounds of Earth (featuring everything from burbling mud pots to barking dogs to a roaring Saturn 5 liftoff); greetings in 55 human languages and one whale language; the brain waves of a young woman in love; and salutations from the secretary general of the United Nations. A team led by Carl Sagan assembled the record as a message to possible extraterrestrial civilizations that might encounter the spacecraft.

"A billion years from now, when everything on Earth we've ever made has crumbled into dust, when the continents have changed beyond recognition and our species is unimaginably altered or extinct, the Voyager record will speak for us," wrote Carl Sagan and Ann Druyan in an introduction to a CD version of the record.

Some people note that the chance of aliens finding the Golden Record is fantastically remote. The Voyager probes won't come within a few light years of another star for some 40,000 years. What are the odds of making contact under such circumstances?

On the other hand, what are the odds of a race of primates evolving to sentience, developing spaceflight, and sending the sound of barking dogs into the cosmos?
Expect the unexpected, indeed.

The Voyagers were built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., which continues to operate both spacecraft. JPL is a division of the California Institute of Technology in Pasadena. The Voyager missions are a part of the NASA Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate.

For more information about the Voyager spacecraft, visit: http://voyager.jpl.nasa.gov and http://www.nasa.gov/voyager .

NASA's Jet Propulsion Laboratory in Pasadena, Calif., will host a Tweetup on Monday, June 6. More than 100 NASA Twitter followers, who registered in April, will attend the event.

With four NASA/JPL space missions launching in 2011 and an asteroid belt encounter nearly underway, this year will be one of the busiest ever in planetary exploration. Tweetup participants will interact with JPL scientists and engineers about these upcoming missions: Aquarius, to study ocean salinity; Grail, to study the moon's gravity field; Juno to Jupiter; and the Mars Science Laboratory/Curiosity rover. Tweetup participants also will learn about the Dawn mission and its planned encounter with the asteroid Vesta.

The Tweetup will take place from approximately 8 a.m. to 5:30 p.m. PDT. The event will be carried live on http://www.ustream.tv/nasajpl2 , and portions will also be broadcast on NASA Television from about 8:15 - 10:30 a.m. PDT and 1:30 - 3:30 p.m. PDT on June 6 at: http://www.nasa.gov/ntv.

The event will include a tour of JPL, hands-on demonstrations and a last chance to see the Curiosity rover before it ships to Florida for its launch in the fall. Tour stops will include the Spacecraft Assembly Facility, where Curiosity is undergoing assembly and testing, the mission control center of NASA's Deep Space Network, and JPL's new Earth Science Center.

Tweetup participants will mingle with fellow attendees and the staff behind @NASA, @NASAJPL, @MarsRovers, @AsteroidWatch and other NASA social media accounts.

NASA's first Tweetup was held at JPL on Jan. 21, 2009, and NASA Headquarters held its first on July 21, 2009. The most recent event was at NASA's Kennedy Space Center for the space shuttle Endeavour's final launch. Following JPL's June event, the next NASA Tweetup will be July 7-8 at Kennedy for the Space Shuttle Program's final launch. Registration for that Tweetup is open from noon EDT (9 a.m. PDT) Wednesday, June 1, through noon Thursday, June 2, at: http://www.nasa.gov/tweetup .

WEB COVERAGE
Follow the conversation before and during the June 6 event on Twitter by using the hashtag #NASATweetup and following the @NASAJPL, @JPLTweetup, and @NASATweetup accounts.

Find all the ways to connect and collaborate with NASA at: http://www.nasa.gov/connect .

The three massive solar panels that will provide power for NASA's Juno spacecraft during its mission to Jupiter have seen their last photons of light until they are deployed in space after launch. The last of the Jupiter-bound spacecraft's panels completed pre-flight testing at the Astrotech payload processing facility in Titusville, Fla., and was folded against the side of the spacecraft into its launch configuration Thursday, May 26. The solar-powered Juno spacecraft will orbit Jupiter's poles 30 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere.

"Completing the testing and stow of solar panels is always a big pre-launch milestone, and with Juno, you could say really big because our panels are really big," said Jan Chodas, Juno's project manager from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The next time these three massive solar arrays are extended to their full length, Juno will be climbing away from the Earth at about seven miles per second."

This is the first time in history a spacecraft has used solar power so far out in space (Jupiter is five times farther from the sun than Earth). To operate on the sun's light that far out requires solar panels about the size of the cargo section of a typical tractor-trailer you'd see on the interstate highway. Even with all that surface area pointed sunward, all three panels, which are 2.7 meters wide (9 feet), by 8.9 meters long (29 feet), will only generate about enough juice to power five standard light bulbs -- about 450 watts of electricity. If the arrays were optimized to operate at Earth, they would produce 12 to 14 kilowatts of power.

In other recent events, the 106-foot-long (32-meter-long), 12.5-foot-wide (3.8-meter-wide) first stage of the United Launch Alliance Atlas V launch vehicle that will carry Juno into space arrived at the Skid Strip at Cape Canaveral Air Force Station on May 24, aboard the world's second largest cargo aircraft -- a Volga-Dnepr Antonov AN-124-100. The two-stage Atlas V, along with the five solid rocket boosters that ring the first stage, will be assembled and tested on site at Launch Complex-41 at Cape Canaveral this summer.

The launch period for Juno opens Aug. 5, 2011, and extends through Aug. 26. For an Aug. 5 liftoff, the launch window opens at 8:39 a.m. PDT (11:39 am EDT) and remains open through 9:39 a.m. PDT (12:39 p.m. EDT).

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, built the spacecraft. Launch management for the mission is the responsibility of NASA's Launch Services Program at the Kennedy Space Center in Florida. JPL is a division of the California Institute of Technology in Pasadena.

More information about Juno is online at http://www.nasa.gov/juno .

You can learn more about the Juno mission to Jupiter by logging on to the mission's new website. The new site was created by Juno Principal Investigator Scott Bolton in conjunction with Radical Media of New York. "It is one-stop shopping for anyone who wants to be entertained as much as informed about space science and the upcoming Juno mission," said Bolton. This Juno website can be found at: http://missionjuno.swri.edu .

Ancient astronomers looked up at the dark skies in wonder, as the stars marched by overhead like precision dancers. In the early 17th century, Galileo Galilei brought the world one step closer to the heavens with his telescope, discovering, among other celestial marvels, moons around Jupiter, and our own moon's pockmarked surface.

Nowadays, the stars are closer to us than ever, thanks to powerful telescopes in space and on the ground. Modern astronomers don't have to step outside, because they get precise data delivered straight to their own laptops. If Galileo could see us now, he'd probably be thrilled by the advances -- and also a little puzzled that astronomy no longer means gazing through telescopes at the twinkling, dark skies.

"You can access a priceless wealth of astronomy data from your couch," said Amy Mainzer, the deputy project scientist for NASA's Wide-field Infrared Survey Explorer mission at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We can do almost all of our research on our laptops."

Sometimes astronomers do take trips out to ground-based observatories. They sleep during the day, and, instead of peering up at the night sky, they command the telescopes from computer screens. Some telescopes can also be operated remotely from laptops. Mainzer and a colleague, Mike Cushing, a member of the WISE team at JPL, recently spent an evening with the stars in a conference room at NASA's Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena.

"I guess in some sense, there is a slight loss of romance doing remote observing," said Cushing. "But it is more than made up for by being able to sleep in your own bed!"

This particular night, Mainzer and Cushing, along with an undergraduate student, Emily DeBaun from Dartmouth College in Hanover, N.H., were on a hunt for brown dwarfs. These are cool, dim stars with somewhat stunted development. They begin life like stars, but never grow massive enough to ignite nuclear fusion and shine with sunlight, as our sun does so brilliantly. Instead, brown dwarfs glow because of the heat leftover from their formation. This heat makes them easy to see with infrared telescopes.

The first brown dwarf wasn't discovered until 1995, though these objects had been predicted to exist as far back as the 1960s. More discoveries rolled in during the early 2000s with the help of data from the Sloan Digital Sky Survey and the Two Micron All-Sky Survey, an infrared all-sky mapping project sponsored by the Infrared Analysis and Processing Center and the University of Massachusetts, Amherst.

The WISE mission promises to find even more of these little stars, with its improved infrared all-sky maps. In fact, WISE will likely more than double the number of known brown dwarfs out to 25 light-years from our sun, and it may even find one that's closer to us than our closet known star, Proxima Centauri, which is about 4 light-years away. The WISE telescope wrapped up its all-sky survey and went into hibernation in Feb. 2011, but astronomers are just now beginning to sift through the data.

Mainzer and Cushing had plucked a few good brown dwarf candidates out of the WISE data. Their next step was to use the NASA Infrared Telescope Facility atop Mauna Kea in Hawaii to gather more information on the objects, and figure out if they are indeed brown dwarfs, and not something else, such as a distant galaxy masquerading as a nearby, cool star. That's what brought them to a quiet conference room late at night, when even the most owlish of the astronomers usually working in the building had gone home.

"You've got Guidedog," said Cushing, talking via speaker-phone to the NASA Infrared Telescope Facility telescope operator in Hawaii. Guidedog is the name of one of the computers that controls the camera on the telescope. The operator took control of the computer in order to focus the telescope.

Throughout the night, Mainzer and Cushing told the operator when they were ready to point the telescope at a different patch of sky, while controlling the specific settings from a software interface on their laptops. The laptop screen was projected onto a big screen in the conference room, where they could get a better view of the software.

One task involved placing their objects of interest into thin windows, or slits, which mask other nearby stars. Once the command was given to capture an image, an instrument on the Infrared Telescope Facility, called a spectrometer, broke apart the object's light into its basic components, much as a prism disperses sunlight into a rainbow. These data were then transformed into plots, called spectra, showing the various light intensities at each wavelength. The resulting peaks and dips revealed molecules making up the object, as well as its temperature.

"I think we bagged another T-dwarf," said Mainzer, referring to a classification system that organizes brown dwarfs according to their temperature. T-dwarfs are about 1,400 to 500 Kelvin (about 1,130 to 230 degrees Celsius). WISE will likely find even colder brown dwarfs, possibly even the elusive Y-dwarfs, which some theories say could be as cold as 200 Kelvin (minus 73 degrees Celsius). If such an object is revealed, it would be the coldest star-like body known.

The search for brown dwarfs continued on into night. Keeping the astronomers awake were bags of sweet-and-sour gummies and M&Ms, not to mention the thrill of discovering new worlds.

They stayed up until about 3 a.m. that night, which was midnight in Hawaii. The telescope was then handed off to another team of remote observers.

"We're still up late with the stars, even though we see them with electronic sensors instead of peering through the telescope with our own eyes," said Mainzer. "But compared to ancient astronomers, I think our sense of awe is the same, and we’re continuing the quest to understand our astonishing universe."