sexta-feira, 16 de junho de 2017

NASA WEB ·SpaceX Fires Up Used Rocket Ahead of Monday Re-Flight

SpaceX Fires Up Used Rocket Ahead of Monday Re-Flight (Photo)

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SpaceX Fires Up Used Rocket Ahead of Monday Re-Flight (Photo)
SpaceX test-fired a Falcon 9 rocket on June 15, 2017, prepping the booster for the planned launch of the BulgariaSat-1 communications satellite on June 19. The liftoff will be the second for this Falcon 9's first stage.
Credit: SpaceX via Twitter
SpaceX test-fired a previously flown Falcon 9 rocket Thursday (June 15), paving the way for the booster's planned second liftoff on Monday (June 19).
"Static fire test of Falcon 9 complete — targeting June 19 launch of BulgariaSat-1 from historic Pad 39A," SpaceX representatives tweeted today, referring to the pad at NASA's Kennedy Space Center in Florida that once hosted Apollo moon-mission launches and space shuttle liftoffs.
The Falcon 9 is a two-stage vehicle. The first stage of this particular rocket helped power 10 communications satellites to orbit on Jan. 14, then came back down to Earth for a landing on a robotic SpaceX ship in the ocean. [Photos of SpaceX's 1st Reused Rocket Launch (& Landing)]

NASA WEB · Martian Crater Provides Reminder of Apollo Moonwalk NASA's Mars Exploration Rover Opportunity passed near a young crater this spring during the 45th anniversary of Apollo 16's trip to Earth's moon, prompting a connection between two missions

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Martian Crater Provides Reminder of Apollo MoonwalkNASA's Mars Exploration Rover Opportunity passed near a young crater this spring during the 45th anniversary of Apollo 16's trip to Earth's moon, prompting a connection between two missions.
Opportunity's science team informally named the Martian feature "Orion Crater." The name honors the Apollo 16 lunar module, Orion, which carried astronauts John Young and Charles Duke to and from the surface of the moon in April 1972 while crewmate Ken Mattingly piloted the Apollo 16 command module, Casper, in orbit around the moon. Orion is also the name of NASA's new spacecraft that will carry humans into deep space and sustain them during travel beyond Earth orbit.
Opportunity's Panoramic Camera (Pancam) took component images for this view of Orion Crater on April 26, 2017. The crater is about 90 feet (27 meters) wide and estimated to be no older than 10 million years.
"It turns out that Orion Crater is almost exactly the same size as Plum Crater on the moon, which John Young and Charles Duke explored on their first of three moonwalks taken while investigating the lunar surface using their lunar rover," said Opportunity science-team member Jim Rice, of the Planetary Science Institute, Tucson, Arizona.
Rice sent Duke the Pancam mosaic of Mars' Orion Crater, and Duke responded, "This is fantastic. What a great job! I wish I could be standing on the rim of Orion like I was standing on the rim of Plum Crater 45 years ago."

NASA WEB ·-NASA scientists have found a wide diversity of minerals in the initial samples of rocks collected by the Curiosity rover in the lowermost layers of Mount Sharp on Mars

Key Locations Studied at 'Pahrump Hills' on Mars

NASA's Curiosity Mars rover examined a mudstone outcrop area called "Pahrump Hills" on lower Mount Sharp, in 2014 and 2015. This view shows locations of some targets the rover studied there. The blue dots indicate where drilled samples of powdered rock were collected for analysis. Credit: NASA/JPL-Caltech/MSSS
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NASA scientists have found a wide diversity of minerals in the initial samples of rocks collected by the Curiosity rover in the lowermost layers of Mount Sharp on Mars, suggesting that conditions changed in the water environments on the planet over time.
Curiosity landed near Mount Sharp in Gale Crater in August 2012. It reached the base of the mountain in 2014. Layers of rocks at the base of Mount Sharp accumulated as sediment within ancient lakes around 3.5 billion years ago. Orbital infrared spectroscopy had shown that the mountain's lowermost layers have variations in minerals that suggest changes in the area have occurred.
In a paper published recently in Earth and Planetary Science Letters, scientists in the Astromaterials Research and Exploration Science (ARES) Division at NASA's Johnson Space Center in Houston report on the first four samples collected from the lower layers of Mount Sharp.
"We went to Gale Crater to investigate these lower layers of Mount Sharp that have these minerals that precipitated from water and suggest different environments," said Elizabeth Rampe, the first author of the study and a NASA exploration mission scientist at Johnson. "These layers were deposited about 3.5 billion years ago, coinciding with a time on Earth when life was beginning to take hold. We think early Mars may have been similar to early Earth, and so these environments might have been habitable."
The minerals found in the four samples drilled near the base of Mount Sharp suggest several different environments were present in ancient Gale Crater. There is evidence for waters with different pH and variably oxidizing conditions. The minerals also show that there were multiple source regions for the rocks in "Pahrump Hills" and "Marias Pass."
The paper primarily reports on three samples from the Pahrump Hills region. This is an outcrop at the base of Mount Sharp that contains sedimentary rocks scientists believe formed in the presence of water. The other sample, called "Buckskin," was reported last year, but those data are incorporated into the paper.
Studying such rock layers can yield information about Mars' past habitability, and determining minerals found in the layers of sedimentary rock yields much data about the environment in which they formed. Data collected at Mount Sharp with the Chemistry and Mineralogy (CheMin) instrument on Curiosity showed a wide diversity of minerals.
At the base are minerals from a primitive magma source; they are rich in iron and magnesium, similar to basalts in Hawaii. Moving higher in the section, scientists saw more silica-rich minerals. In the "Telegraph Peak" sample, scientists found minerals similar to quartz. In the "Buckskin" sample, scientists found tridymite. Tridymite is found on Earth, for example, in rocks that formed from partial melting of Earth's crust or in the continental crust -- a strange finding because Mars never had plate tectonics.
In the "Confidence Hills" and "Mojave 2" samples, scientists found clay minerals, which generally form in the presence of liquid water with a near-neutral pH, and therefore could be good indicators of past environments that were conducive to life. The other mineral discovered here was jarosite, a salt that forms in acidic solutions. The jarosite finding indicates that there were acidic fluids at some point in time in this region.
There are different iron-oxide minerals in the samples as well. Hematite was found near the base; only magnetite was found at the top. Hematite contains oxidized iron, whereas magnetite contains both oxidized and reduced forms of iron. The type of iron-oxide mineral present may tell scientists about the oxidation potential of the ancient waters.
The authors discuss two hypotheses to explain this mineralogical diversity. The lake waters themselves at the base were oxidizing, so either there was more oxygen in the atmosphere or other factors encouraged oxidation. Another hypothesis -- the one put forward in the paper -- is that later-stage fluids arose. After the rock sediments were deposited, some acidic, oxidizing groundwater moved into the area, leading to precipitation of the jarosite and hematite. In this scenario, the environmental conditions present in the lake and in later groundwater were quite different, but both offered liquid water and a chemical diversity that could have been exploited by microbial life.
"We have all this evidence that Mars was once really wet but now is dry and cold," Rampe said. "Today, much of the water is locked up in the poles and in the ground at high latitudes as ice. We think that the rocks Curiosity has studied reveal ancient environmental changes that occurred as Mars started to lose its atmosphere and water was lost to space."
In the paper, the authors discuss whether this specific area on Mars is a mark of this event happening or just a natural drying of this area. Scientists will search for answers to these questions as the rover moves up the mountain.

NASA WEB · The moon hanging in the night sky sent Robert Hurt's mind into deep space -- to a region some 40 light years away, in fact, where seven Earth-sized planets crowded close to a dim, red sun.

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The Art of ExoplanetsThe moon hanging in the night sky sent Robert Hurt's mind into deep space -- to a region some 40 light years away, in fact, where seven Earth-sized planets crowded close to a dim, red sun.
Hurt, a visualization scientist at Caltech's IPAC center, was walking outside his home in Mar Vista, California, shortly after he learned of the discovery of these rocky worlds around a star called TRAPPIST-1 and got the assignment to visualize them. The planets had been revealed by NASA's Spitzer Space Telescope and ground-based observatories.
"I just stopped dead in my tracks, and I just stared at it," Hurt said in an interview. "I was imagining that could be, not our moon, but the next planet over - what it would be like to be in a system where you could look up and see continental features on the next planet."
› DOWNLOAD VIDEO Art of AstrophysicsSo began a kind of inspirational avalanche. Hurt and his colleague, multimedia producer Tim Pyle, developed a series of arresting, photorealistic images of what the new system's tightly packed planets might look like -- so tightly packed that they would loom large in each other's skies. Their visions of the TRAPPIST-1 system would appear in leading news outlets around the world.
Artists like Hurt and Pyle, who render vibrant visualizations based on data from Spitzer and other missions, are hybrids of sorts, blending expertise in both science and art. From squiggles on charts and columns of numbers, they conjure red, blue and green worlds, with half-frozen oceans or bubbling lava. Or they transport us to the surface of a world with a red-orange sun fixed in place, and a sky full of planetary companions.
"For the public, the value of this is not just giving them a picture of something somebody made up," said Douglas Hudgins, a program scientist for the Exoplanet Exploration Program at NASA Headquarters in Washington. "These are real, educated guesses of how something might look to human beings. An image is worth a thousand words."
Hurt says he and Pyle are building on the work of artistic pioneers.
"There's actually a long history and tradition for space art and science-based illustration," he said. "If you trace its roots back to the artist Chesley Bonestell (famous in the 1950s and '60s), he really was the artist who got this idea: Let's go and imagine what the planets in our solar system might actually look like if you were, say, on Jupiter's moon, Io. How big would Jupiter appear in the sky, and what angle would we be viewing it from?"
To begin work on their visualizations, Hurt divided up the seven TRAPPIST-1 planets with Pyle, who shares an office with him at Caltech's IPAC center in Pasadena, California.
Hurt holds a Ph.D. in astrophysics, and has worked at the center since he was a post-doctoral researcher in 1996 - when astronomical art was just his hobby.
"They created a job for me," he said.
Pyle, whose background is in Hollywood special effects, joined Hurt in 2004.
Hurt turns to Pyle for artistic inspiration, while Pyle relies on Hurt to check his science.
"Robert and I have our desks right next to each other, so we're constantly giving each other feedback," Pyle said. "We're each upping each other's game, I think."
The TRAPPIST-1 worlds offered both of them a unique challenge. The two already had a reputation for illustrating many exoplanets - planets around stars beyond our own -- but never seven Earth-sized worlds in a single system. The planets cluster so close to their star that a "year" on each of them -- the time they take to complete a single orbit -- can be numbered in Earth days.
And like the overwhelming majority of the thousands of exoplanets found so far, they were detected using indirect means. No telescope exists today that is powerful enough to photograph them.
Real science informed their artistic vision. Using data from the telescopes that reveal each planet's diameter as well as its "weight," or mass, and known stellar physics to determine the amount of light each planet would receive, the artists went to work.
Both consulted closely with the planets' discovery team as they planned for a NASA announcement to coincide with a report in the journal Nature.
"When we're doing these artist's concepts, we're never saying, 'This is what these planets actually look like,'" Pyle said. "We're doing plausible illustrations of what they could look like, based on what we know so far. Having this wide range of seven planets actually let us illustrate almost the whole breadth of what would be plausible. This was going to be this incredible interstellar laboratory for what could happen on an Earth-sized planet."
For TRAPPIST-1b, Pyle took Jupiter's volcanic moon, Io, as an inspiration, based on suggestions from the science team. For the outermost world, TRAPPIST-1h, he chose two other Jovian moons, the ice-encased Ganymede and Europa.
After talking to the scientists, Hurt portrayed TRAPPIST-1c as dry and rocky. But because all seven planets are probably tidally locked, forever presenting one face to their star and the other to the cosmos, he placed an ice cap on the dark side.
TRAPPIST-1d was one of three that fall inside the "habitable zone" of the star, or the right distance away from it to allow possible liquid water on the surface.
"The researchers told us they would like to see it portrayed as something they called an 'eyeball world,'" Hurt said. "You have a dry, hot side that's facing the star and an ice cap on the back side. But somewhere in between, you have (a zone) where the ice could melt and be sustained as liquid water."
At this point, Hurt said, art intervened. The scientists rejected his first version of the planet, which showed liquid water intruding far into the "dayside" of TRAPPIST-1d. They argued that the water would most likely be found well within the planet's dark half.
"Then I kind of pushed back, and said, 'If it's on the dark side, no one can look at it and understand we're saying there's water there,'" Hurt said. They struck a compromise: more water toward the dayside than the science team might expect, but a better visual representation of the science.
The same push and pull between science and art extends to other forms of astronomical visualization, whether it's a Valentine's Day cartoon of a star pulsing like a heart in time with its planet, or materials for the blockbuster announcement of the first detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory in February 2016. They've also illustrated asteroids, neutron stars, pulsars and brown dwarfs.
Visualizations based on data can also inform science, leading to genuine scientific insights. The scientists' conclusions about TRAPPIST-1 at first seemed to suggest the planets would be bathed in red light, potentially obscuring features like blue-hued bodies of water.
"It makes it hard to really differentiate what is going on," Hurt said.
Hurt decided to investigate. A colleague provided him with a spectrum of a red dwarf star similar to TRAPPIST-1. He overlaid that with the "responsivity curves" of the human eye, and found that most of the scientists' "red" came from infrared light, invisible to human eyes. Subtract that, and what is left is a more reddish-orange hue that we might see standing on the surface of a TRAPPIST-1 world -- "kind of the same color you would expect to get from a low-wattage light bulb," Hurt said. "And the scientists looked at that and said, 'Oh, ok, great, it's orange.' When the math tells you the answer, there really isn't a lot to argue about."
For Hurt, the real goal of scientific illustration is to excite the public, engage them in the science, and provide a snapshot of scientific knowledge.
"If you look at the whole history of space art, reaching back many, many decades, you will find you have a visual record," he said. "The art is a historical record of our changing understanding of the universe. It becomes a part of the story, and a part of the research, I think."

quarta-feira, 7 de junho de 2017

NASA WEB ·Flares May Threaten Planet Habitability Near Red Dwarfs

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Flares May Threaten Planet Habitability Near Red DwarfsCool dwarf stars are hot targets for exoplanet hunting right now. The discoveries of planets in the habitable zones of the TRAPPIST-1 and LHS 1140 systems, for example, suggest that Earth-sized worlds might circle billions of red dwarf stars, the most common type of star in our galaxy. But, like our own sun, many of these stars erupt with intense flares. Are red dwarfs really as friendly to life as they appear, or do these flares make the surfaces of any orbiting planets inhospitable?
To address this question, a team of scientists has combed 10 years of ultraviolet observations by NASA's Galaxy Evolution Explorer (GALEX) spacecraft looking for rapid increases in the brightness of stars due to flares. Flares emit radiation across a wide swath of wavelengths, with a significant fraction of their total energy released in the ultraviolet bands where GALEX observed. At the same time, the red dwarfs from which the flares arise are relatively dim in ultraviolet. This contrast, combined with the GALEX detectors' sensitivity to fast changes, allowed the team to measure events with less total energy than many previously detected flares. This is important because, although individually less energetic and therefore less hostile to life, smaller flares might be much more frequent and add up over time to create an inhospitable environment.
"What if planets are constantly bathed by these smaller, but still significant, flares?" asked Scott Fleming of the Space Telescope Science Institute (STScI) in Baltimore. "There could be a cumulative effect."
To detect and accurately measure these flares, the team had to analyze data over very short time intervals. From images with exposure times of nearly half an hour, the team was able to reveal stellar variations lasting just seconds.
First author Chase Million of Million Concepts in State College, Pennsylvania, led a project called gPhoton that reprocessed more than 100 terabytes of GALEX data held at the Mikulski Archive for Space Telescopes (MAST), located at the Space Telescope Science Institute. The team then used custom software developed by Million and Clara Brasseur, also at the institute, to search several hundred red dwarf stars, and they detected dozens of flares.
"We have found dwarf star flares in the whole range that we expected GALEX to be sensitive to, from itty bitty baby flares that last a few seconds, to monster flares that make a star hundreds of times brighter for a few minutes," said Million.
The flares GALEX detected are similar in strength to flares produced by our own sun. However, because a planet would have to orbit much closer to a cool, red dwarf star to maintain a temperature friendly to life as we know it, such planets would be subjected to more of a flare's energy than Earth.
Large flares can strip away a planet's atmosphere. Strong ultraviolet light from flares that penetrates to a planet's surface could damage organisms or prevent life from arising.
Currently, team members Rachel Osten and Brasseur are examining stars observed by both the GALEX and Kepler missions to look for similar flares. The team expects to eventually find hundreds of thousands of flares hidden in the GALEX data.
"These results show the value of a survey mission like GALEX, which was instigated to study the evolution of galaxies across cosmic time and is now having an impact on the study of nearby habitable planets," said Don Neill, research scientist at Caltech in Pasadena, who was part of the GALEX collaboration. "We did not anticipate that GALEX would be used for exoplanets when the mission was designed."
New and powerful instruments like NASA's James Webb Space Telescope, scheduled for launch in 2018, ultimately will be needed to study atmospheres of planets orbiting nearby red dwarf stars and search for signs of life. But as researchers pose new questions about the cosmos, archives of data from past projects and missions, like those held at MAST, continue to produce exciting new scientific results.
These results were presented in a news conference at a meeting of the American Astronomical Society in Austin, Texas.
The GALEX mission, which ended in 2013 after more than a decade of scanning the skies in ultraviolet light, was led by scientists at Caltech. NASA's Jet Propulsion Laboratory, also in Pasadena, managed the mission and built the science instrument. JPL is managed by Caltech for NASA.
STScI conducts Hubble Space Telescope science operations and is the mission and science operations center for the James Webb Space Telescope. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington.

quinta-feira, 18 de maio de 2017

NASA WEB ·Movie Shows Ceres at Opposition from Sun

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Movie Shows Ceres at Opposition from SunNASA's Dawn spacecraft successfully observed Ceres at opposition on April 29, taking images from a position exactly between the sun and Ceres' surface. Mission specialists had carefully maneuvered Dawn into a special orbit so that the spacecraft could view Occator Crater, which contains the brightest area of Ceres, from this new perspective.
A new movie shows these opposition images, with contrast enhanced to highlight brightness differences. The bright spots of Occator stand out particularly well on an otherwise relatively bland surface. Dawn took these images from an altitude of about 12,000 miles (20,000 kilometers).
Based on data from ground-based telescopes and spacecraft that previously viewed planetary bodies at opposition, scientists correctly predicted that Ceres would appear brighter from this opposition configuration. This increase in brightness, or "surge," relates the size of the grains of material on the surface, as well as the porosity of those materials. The science motivation for performing these observations is further explained in the March issue of the Dawn Journal blog.
Dawn's observations of Ceres during its more than two years there cover a broader range of illumination angles than almost any body in the solar system. This provides scientists with an opportunity to gain new insights into the surface properties. They are currently analyzing the new data.
The new observations and images were largely unaffected by the loss of function of Dawn's third reaction wheel. The spacecraft is healthy and orients itself using its hydrazine thrusters.
Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.
For a complete list of Dawn mission participants, visit:

NASA WEB ·Scientists Look to Skies to Improve Tsunami Detection

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Scientists Look to Skies to Improve Tsunami DetectionA team of scientists from Sapienza University in Rome, Italy, and NASA's Jet Propulsion Laboratory in Pasadena, California, has developed a new approach to assist in the ongoing development of timely tsunami detection systems, based upon measurements of how tsunamis disturb a part of Earth's atmosphere.
The new approach, called Variometric Approach for Real-time Ionosphere Observation, or VARION, uses observations from GPS and other global navigation satellite systems (GNSS) to detect, in real time, disturbances in Earth's ionosphere associated with a tsunami. The ionosphere is the layer of Earth's atmosphere located from about 50 to 621 miles (80 to 1,000 kilometers) above Earth's surface. It is ionized by solar and cosmic radiation and is best known for the aurora borealis (northern lights) and aurora australis (southern lights).
When a tsunami forms and moves across the ocean, the crests and troughs of its waves compress and extend the air above them, creating motions in the atmosphere known as internal gravity waves. The undulations of internal gravity waves are amplified as they travel upward into an atmosphere that becomes thinner with altitude. When the waves reach an altitude of between 186 to 217 miles (300 to 350 kilometers), they cause detectable changes to the density of electrons in the ionosphere. These changes can be measured when GNSS signals, such as those of GPS, travel through these tsunami-induced disturbances.
VARION was designed under the leadership of Sapienza's Mattia Crespi. The main author of the algorithm is Giorgio Savastano, a doctoral student in geodesy and geomatics at Sapienza and an affiliate employee at JPL, which conducted further development and validation of the algorithm. The work was outlined recently in a Sapienza- and NASA-funded study published in Nature's Scientific Reports journal.
In 2015, Savastano was awarded a fellowship by Consiglio Nazionale degli Ingegneri (CNI) and Italian Scientists and Scholars in North America Foundation (ISSNAP) for a two-month internship at JPL, where he joined the Ionospheric and Atmospheric Remote Sensing Group under the supervision of Attila Komjathy and Anthony Mannucci.
"VARION is a novel contribution to future integrated operational tsunami early warning systems," said Savastano. "We are currently incorporating the algorithm into JPL's Global Differential GPS System, which will provide real-time access to data from about 230 GNSS stations around the world that collect data from multiple satellite constellations, including GPS, Galileo, GLONASS and BeiDou." Since significant tsunamis are infrequent, exercising VARION using a variety of real-time data will help validate the algorithm and advance research on this tsunami detection approach.
Savastano says VARION can be included in design studies for timely tsunami detection systems that use data from a variety of sources, including seismometers, buoys, GNSS receivers and ocean-bottom pressure sensors.
Once an earthquake is detected in a specific location, a system could begin processing real-time measurements of the distribution of electrons in the ionosphere from multiple ground stations located near the quake's epicenter, searching for changes that may be correlated with the expected formation of a tsunami. The measurements would be collected and processed by a central processing facility to provide risk assessments and maps for individual earthquake events. The use of multiple independent data types is expected to contribute to the system's robustness.
"We expect to show it is feasible to use ionospheric measurements to detect tsunamis before they impact populated areas," said Komjathy. "This approach will add additional information to existing systems, complementing other approaches. Other hazards may also be targeted using real-time ionospheric observations, including volcanic eruptions or meteorites."
Observing the ionosphere, and how terrestrial weather below it interfaces with space above, continues to be an important focus for NASA. Two new missions -- the Ionospheric Connection Explorer and the Global-scale Observations of the Limb and Disk -- are planned to launch by early 2018 to observe the ionosphere, which should ultimately improve a wide array of models used to protect humans on the ground and satellites in space.

NASA WEB ·NASA's CPEX Tackles a Weather Fundamental

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NASA's CPEX Tackles a Weather FundamentalA NASA-funded field campaign getting underway in Florida on May 25 has a real shot at improving meteorologists' ability to answer some of the most fundamental questions about weather: Where will it rain? When? How much?
Called the Convective Processes Experiment (CPEX), the campaign is using NASA's DC-8 airborne laboratory outfitted with five complementary research instruments designed and developed at NASA. The plane also will carry small sensors called dropsondes that are dropped from the plane and make measurements as they fall. Working together, the instruments will collect detailed data on wind, temperature and humidity in the air below the plane during the birth, growth and decay of convective clouds -- clouds formed by warm, moist air rising off the subtropical waters around Florida.
"Convection is simply a column or bubble of warm air rising," said CPEX Principal Investigator Ed Zipser of the University of Utah in Salt Lake City. That rising air may become the seed of a rainstorm; in the tropics and subtropics, including the U.S. South, convection is the most common way for precipitation to form. Convective clouds can join together to form a major rainstorm or can even become a hurricane.
Even though convection is such a fundamental atmospheric process, the start of convection has proven difficult to predict. Bjorn Lambrigtsen of NASA's Jet Propulsion Laboratory in Pasadena, California, a member of the CPEX science team, explained why: "Tropical convection flares up quickly. A thunderstorm pops up, does its thing, and goes away in an hour or so. And they're not very large." They're typically less than six miles (10 kilometers) across. Satellites can't observe much detail about a feature that small even if they happen to be looking at the right place at the right time. "To understand what makes a thunderstorm form and grow, we need field campaigns. We need to fly to where the storms are, look at them and their environment in detail, and measure all the important features at the same time," said Lambrigtsen.
Zipser is particularly interested in areas of deep convection, with cloud tops higher than jets fly. "If you look at a vacation poster of Hawaii, you see a sky full of little cotton balls," he says. "Those clouds are only a few kilometers deep, and you might get a light shower out of them. The troposphere over the tropics is 14 or 15 kilometers [9 miles] deep, and the top half of deep convective clouds is full of ice particles instead of liquid drops. If these deep clouds become better organized, grow into a large system and move over land, you can have widespread, heavy rainfall for the better part of a day. We need to find out when deep convection is going to form and why."
One Month, One Plane, Five Instruments
The CPEX team plans to log 10 to 16 flights in June for a total of about 100 flight hours, weather permitting. They hope to record the entire evolution of convective storms, from birth to decay. They'll fly in whichever direction the weather seems most promising, whether it's the Gulf of Mexico, the Caribbean or the western Atlantic Ocean. The most interesting data should come when the plane is able to penetrate deep but moderate convection without the threat of lightning, collecting data from inside a storm or storm system.
The five NASA instruments are flying together as a group for the first time:
  • DAWN, the Doppler Aerosol Wind Lidar, is a relatively new addition to NASA's Earth science toolkit that measures the horizontal wind profile below the plane. It was developed and is operated by NASA's Langley Research Center in Hampton, Virginia. Lambrigtsen noted that in contrast with dropsondes, which collect data only from the spots where they're dropped, DAWN collects a swath of continuous data along the flight path. "It's one of the most important measurements for understanding tropical convection, and it was not available till DAWN and similar sensors came on the scene," Lambrigtsen said.
  • APR-2, the Airborne Second-Generation Precipitation Radar, measures precipitation and vertical motion within storms using the same kind of dual-polarization, dual-Doppler technology as the National Weather Service's ground-based radar. Developed and operated by JPL, APR-2 measures the rain or ice particles in a cloud, which reveal the cloud's structure.
  • Three microwave radiometers from JPL measure what Lambrigtsen calls "the bread and butter of convection" -- temperature, water vapor, and the amount of liquid in clouds:
    • HAMSR, the High Altitude MMIC (Monolithic Microwave integrated Circuit) Sounding Radiometer;
    • MTHP, the Microwave Temperature and Humidity Profiler
    • MASC, the Microwave Atmospheric Sounder for Cubesats. This experimental instrument will test the possibility of flying a miniaturized microwave radiometer on a tiny satellite called a Cubesat. JPL scientists will assess MASC's performance in CPEX to advance the instrument along the path to space readiness.
The DC-8 aircraft and crew are based at NASA's Armstrong Flight Research Center in Palmdale, California.
Better Understanding, Improved Models
With a career stretching back to the 1960s, Ed Zipser knows as well as anyone how a good data set from field research can advance understanding of the atmosphere and improve the accuracy of weather and climate models. "We've known since the 1970s that the key to a successful forecast is being able to understand and treat the role of convection," he said. "We've made a lot of progress, but none of the model treatments of convection is anything you could call perfect. We need to observe better and understand more. CPEX is a pretty exciting opportunity to learn more about convection and its evolution."

quarta-feira, 3 de maio de 2017

NASA WEB ·Cassini Finds 'The Big Empty' Close to Saturn

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Cassini Finds 'The Big Empty' Close to SaturnAs NASA's Cassini spacecraft prepares to shoot the narrow gap between Saturn and its rings for the second time in its Grand Finale, Cassini engineers are delighted, while ring scientists are puzzled, that the region appears to be relatively dust-free. This assessment is based on data Cassini collected during its first dive through the region on April 26.
With this information in hand, the Cassini team will now move forward with its preferred plan of science observations.
"The region between the rings and Saturn is 'the big empty,' apparently," said Cassini Project Manager Earl Maize of NASA's Jet Propulsion Laboratory in Pasadena, California. "Cassini will stay the course, while the scientists work on the mystery of why the dust level is much lower than expected."
A dustier environment in the gap might have meant the spacecraft's saucer-shaped main antenna would be needed as a shield during most future dives through the ring plane. This would have forced changes to how and when Cassini's instruments would be able to make observations. Fortunately, it appears that the "plan B" option is no longer needed. (There are 21 dives remaining. Four of them pass through the innermost fringes of Saturn's rings, necessitating that the antenna be used as a shield on those orbits.)
Based on images from Cassini, models of the ring particle environment in the approximately 1,200-mile-wide (2,000-kilometer-wide) region between Saturn and its rings suggested the area would not have large particles that would pose a danger to the spacecraft.
But because no spacecraft had ever passed through the region before, Cassini engineers oriented the spacecraft so that its 13-foot-wide (4-meter-wide) antenna pointed in the direction of oncoming ring particles, shielding its delicate instruments as a protective measure during its April 26 dive.
Cassini's Radio and Plasma Wave Science (RPWS) instrument was one of two science instruments with sensors that poke out from the protective shield of the antenna (the other being Cassini'smagnetometer). RPWS detected the hits of hundreds of ring particles per second when it crossed the ring plane just outside of Saturn's main rings, but only detected a few pings on April 26.
When RPWS data are converted to an audio format, dust particles hitting the instrument's antennas sound like pops and cracks, covering up the usual whistles and squeaks of waves in the charged particle environment that the instrument is designed to detect. The RPWS team expected to hear a lot of pops and cracks on crossing the ring plane inside the gap, but instead, the whistles and squeaks came through surprisingly clearly on April 26.
"It was a bit disorienting -- we weren't hearing what we expected to hear," said William Kurth, RPWS team lead at the University of Iowa, Iowa City. "I've listened to our data from the first dive several times and I can probably count on my hands the number of dust particle impacts I hear."
The team's analysis suggests Cassini only encountered a few particles as it crossed the gap -- none larger than those in smoke (about 1 micron across).
Cassini will next cross through the ring plane Tuesday, May 2, at 12:38 p.m. PDT (3:38 p.m. EDT) in a region very close to where it passed on the previous dive. During this orbit, in advance of the crossing, Cassini's cameras have been looking closely at the rings; in addition, the spacecraft has rotated (or "rolled") faster than engineers have ever allowed it to before, in order to calibrate the magnetometer. As with the first finale dive, Cassini will be out of contact during closest approach to Saturn, and is scheduled to transmit data from this dive on May 3.
More information about Cassini's Grand Finale, including images and video, is available at:
The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter.
More information about Cassini:

sábado, 22 de abril de 2017

NASA WEB ·NASA to Host News Conference on Discovery Beyond Our Solar System

Artist's concept of Kepler-452b


NASA to Host News Conference on Discovery Beyond Our Solar System

NASA will hold a news conference at 1 p.m. EST Wednesday, Feb. 22, to present new findings on planets that orbit stars other than our sun, known as exoplanets. The event will air live on NASA Television and the agency's website.
Details of these findings are embargoed by the journal Nature until 1 p.m.
Editor's Note: The news release on the findings is now available: NASA Telescope Reveals Largest Batch of Earth-Size, Habitable-Zone Planets Around Single Star
Limited seating is available in the NASA TV studio for media who would like to attend in person at the agency’s Headquarters at 300 E Street SW in Washington. Media unable to attend in person may ask questions by telephone. To attend in person or participate by phone, media must send an email with their name, affiliation and telephone number to Dwayne Brown at by noon Feb. 22.
Media and the public also may ask questions during the briefing on Twitter using the hashtag #askNASA.
The briefing participants are:
·        Thomas Zurbuchen, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington
·        Michael Gillon, astronomer at the University of Liege in Belgium
·        Sean Carey, manager of NASA's Spitzer Science Center at Caltech/IPAC, Pasadena, California
·        Nikole Lewis, astronomer at the Space Telescope Science Institute in Baltimore
·        Sara Seager, professor of planetary science and physics at Massachusetts Institute of Technology, Cambridge
A Reddit AMA (Ask Me Anything) about exoplanets will be held following the briefing at 3 p.m. with scientists available to answer questions in English and Spanish.

sábado, 8 de abril de 2017

NASA WEB ·NASA Invests in 22 Visionary Exploration Concepts

NASA JPL latest news release
NASA Invests in 22 Visionary Exploration ConceptsA mechanical rover inspired by a Dutch artist. A weather balloon that recharges its batteries in the clouds of Venus.
These are just two of the five ideas that originated at NASA's Jet Propulsion Laboratory in Pasadena, California, and are advancing for a new round of research funded by the agency.
In total, the space agency is investing in 22 early-stage technology proposals that have the potential to transform future human and robotic exploration missions, introduce new exploration capabilities, and significantly improve current approaches to building and operating aerospace systems.
The 2017 NASA Innovative Advanced Concepts (NIAC) portfolio of Phase I concepts covers a wide range of innovations selected for their potential to revolutionize future space exploration. Phase I awards are valued at approximately $125,000, for nine months, to support initial definition and analysis of their concepts. If these basic feasibility studies are successful, awardees can apply for Phase II awards.
"The NIAC program engages researchers and innovators in the scientific and engineering communities, including agency civil servants," said Steve Jurczyk, associate administrator of NASA's Space Technology Mission Directorate. "The program gives fellows the opportunity and funding to explore visionary aerospace concepts that we appraise and potentially fold into our early stage technology portfolio."
The selected 2017 Phase I proposals are:
• A Synthetic Biology Architecture to Detoxify and Enrich Mars Soil for Agriculture, Adam Arkin, University of California, Berkeley
• A Breakthrough Propulsion Architecture for Interstellar Precursor Missions, John Brophy, NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California
• Evacuated Airship for Mars Missions, John-Paul Clarke, Georgia Institute of Technology in Atlanta
• Mach Effects for In Space Propulsion: Interstellar Mission, Heidi Fearn, Space Studies Institute in Mojave, California
• Pluto Hop, Skip, and Jump, Benjamin Goldman, Global Aerospace Corporation in Irwindale, California
• Turbolift, Jason Gruber, Innovative Medical Solutions Group in Tampa, Florida
• Phobos L1 Operational Tether Experiment, Kevin Kempton, NASA's Langley Research Center in Hampton, Virginia
• Gradient Field Imploding Liner Fusion Propulsion System, Michael LaPointe, NASA's Marshall Space Flight Center in Huntsville, Alabama
• Massively Expanded NEA Accessibility via Microwave-Sintered Aerobrakes, John Lewis, Deep Space Industries, Inc., in Moffett Field, California
• Dismantling Rubble Pile Asteroids with Area-of-Effect Soft-bots, Jay McMahon, University of Colorado, Boulder
• Continuous Electrode Inertial Electrostatic Confinement Fusion, Raymond Sedwick, University of Maryland, College Park
• Sutter: Breakthrough Telescope Innovation for Asteroid Survey Missions to Start a Gold Rush in Space, Joel Sercel, TransAstra in Lake View Terrace, California
• Direct Multipixel Imaging and Spectroscopy of an Exoplanet with a Solar Gravity Lens Mission, Slava Turyshev, JPL
• Solar Surfing, Robert Youngquist, NASA's Kennedy Space Center in Florida
• A Direct Probe of Dark Energy Interactions with a Solar System Laboratory, Nan Yu, JPL
"The 2017 NIAC Phase I competition has resulted in an excellent set of studies. All of the final candidates were outstanding," said Jason Derleth, NIAC program executive. "We look forward to seeing how each new study will expand how we explore the universe."
Phase II studies allow awardees time to refine their designs and explore aspects of implementing the new technology. This year's Phase II portfolio addresses a range of leading-edge concepts, including: a Venus probe using in-situ power and propulsion to study the Venusian atmosphere, and novel orbital imaging data derived from stellar echo techniques -- measurement of the variation in a star's light caused by reflections off of distant worlds -- to detect exoplanets, which are planets outside our solar system.
Awards under Phase II of the NIAC program can be worth as much as $500,000, for two-year studies, and allow proposers to further develop Phase I concepts that successfully demonstrated initial feasibility and benefit.
The selected 2017 Phase II proposals are:
• Venus Interior Probe Using In-situ Power and Propulsion, Ratnakumar Bugga, JPL
• Remote Laser Evaporative Molecular Absorption Spectroscopy Sensor System, Gary Hughes, California Polytechnic State University in San Luis Obispo
• Brane Craft Phase II, Siegfried Janson, The Aerospace Corporation in El Segundo, California
• Stellar Echo Imaging of Exoplanets, Chris Mann, Nanohmics, Inc., Austin, Texas
• Automaton Rover for Extreme Environments, Jonathan Sauder, JPL
• Optical Mining of Asteroids, Moons, and Planets to Enable Sustainable Human Exploration and Space Industrialization, Joel Sercel, TransAstra Corp.
• Fusion-Enabled Pluto Orbiter and Lander, Stephanie Thomas, Princeton Satellite Systems, Inc., Plainsboro, New Jersey
"Phase II studies can accomplish a great deal in their two years with NIAC. It is always wonderful to see how our Fellows plan to excel," said Derleth. "The 2017 NIAC Phase II studies are exciting, and it is wonderful to be able to welcome these innovators back in to the program. Hopefully, they will all go on to do what NIAC does best -- change the possible."
NASA selected these projects through a peer-review process that evaluated innovativeness and technical viability. All projects are still in the early stages of development, most requiring 10 or more years of concept maturation and technology development before use on a NASA mission.
NIAC partners with forward-thinking scientists, engineers, and citizen inventors from across the nation to help maintain America's leadership in air and space. NIAC is funded by NASA's Space Technology Mission Directorate, which is responsible for developing the cross-cutting, pioneering, new technologies and capabilities needed by the agency to achieve its current and future missions

quinta-feira, 30 de março de 2017

NASA WEB · Search for stellar survivor of a supernova explosion

Search for stellar survivor of a supernova explosion

30 March 2017
Astronomers have used the NASA/ESA Hubble Space Telescope to observe the remnant of a supernova explosion in the Large Magellanic Cloud. Beyond just delivering a beautiful image, Hubble may well have traced the surviving remains of the exploded star’s companion.
A group of astronomers used Hubble to study the remnant of the Type Ia supernova explosion SNR 0509-68.7 — also known as N103B (seen at the top). The supernova remnant is located in the Large Magellanic Cloud, just over 160 000 light-years from Earth. In contrast to many other Supernova remnants N103B does not appear to have a spherical shape but is strongly elliptical. Astronomers assume that part of material ejected by the explosion hit a denser cloud of interstellar material, which slowed its speed. The shell of expanding material being open to one side supports this idea.
The relative proximity of N103B allows astronomers to study the life cycles of stars in another galaxy in great detail. And probably even to lift the veil on questions surrounding this type of supernova. The predictable luminosity of Type Ia supernovae means that astronomers can use them as cosmic standard candles to measure their distances, making them useful tools in studying the cosmos. Their exact nature, however, is still a matter of debate. Astronomers suspect Type Ia supernovae occur in binary systems in which at least one of the stars in the pair is awhite dwarf [1].
There are currently two main theories describing how these binary systems become supernovae. Studies like the one that has provided the new image of N103B — that involve searching for remnants of past explosions — can help astronomers to finally confirm one of the two theories.
One theory assumes that both stars in the binary are white dwarfs. If the stars merge with one another it would ultimately lead to a supernova explosion of type Ia.
The second theory proposes that only one star in the system is a white dwarf, while its companion is a normal star. In this theory material from the companion star is accreted onto the white dwarf until its mass reaches a limit, leading to a dramatic explosion. In that scenario, the theory indicates that the normal star should survive the blast in at least some form. However, to date no residual companion around any type Ia supernova has been found.
Astronomers observed the N103B supernova remnant in a search for such a companion. They looked at the region in H-alpha — which highlights regions of gas ionised by the radiation from nearby stars —  to locate supernova shock fronts. They hoped to find a star near the centre of the explosion which is indicated by the curved shock fronts. The discovery of a surviving companion would put an end to the ongoing discussion about the origin of type Ia supernova.
And indeed they found one candidate star that meets the criteria — for star type, temperature, luminosity and distance from the centre of the original supernova explosion. This star has approximately the same mass as the Sun, but it is surrounded by an envelope of hot material that was likely ejected from the pre-supernova system.
Although this star is a reasonable contender for N103B’s surviving companion, its status cannot be confirmed yet without further investigation and a spectroscopic confirmation. The search is still ongoing.

NASA WEB ·NASA to Preview 'Grand Finale' of Cassini Saturn Mission

NASA's Cassini spacecraft will make 22 orbits of Saturn during its Grand Finale, exploring a totally new region between the planet and its rings. Image credit: NASA/JPL-Caltech
› Larger view
NASA will hold a news conference at noon PDT (3 p.m. EDT) Tuesday, April 4, at the agency's Jet Propulsion Laboratory in Pasadena, California, to preview the beginning of Cassini's final mission segment, known as the Grand Finale, which begins in late April. The briefing will air live on NASA Television and the agency's website.
Cassini has been orbiting Saturn since June 2004, studying the planet, its rings and its moons. A final close flyby of Saturn's moon Titan on April 22 will reshape the Cassini spacecraft's orbit so that it begins its final series of 22 weekly dives through the unexplored gap between the planet and its rings. The first of these dives is planned for April 26. Following these closer-than-ever encounters with the giant planet, Cassini will make a mission-ending plunge into Saturn's upper atmosphere on Sept. 15.