Friday, July 18, 2014

OCO-2 Takes the A-Train to Study Earth's Atmosphere

OCO-2 Takes the A-Train to Study Earth's Atmosphere:

OCO-2 will become the leader of the Afternoon Constellation
OCO-2 will become the leader of the Afternoon Constellation, or A-Train, as shown in this artist's concept. Japan's Global Change Observation Mission - Water (GCOM-W1) satellite and NASA's Aqua, CALIPSO, CloudSat and Aura satellites follow. Image Credit: NASA

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July 03, 2014

Every day, above our planet, five Earth-observing satellites rush along like trains on the same "track," flying minutes, and sometimes seconds, behind one another. They carry more than 15 scientific instruments in total, looking at many different aspects of our home planet. Called the Afternoon Constellation, or A-Train, these satellites work as a united, powerful tool for advancing our understanding of Earth's surface and atmosphere.

The train is about to get longer. NASA's Orbiting Carbon Observatory-2 (OCO-2), which launched July 2, will be the A-Train's sixth member. Its mission is to measure atmospheric carbon dioxide, a greenhouse gas that makes up a greater percentage of our atmosphere today than it has in at least 800,000 years. It will produce data that will help scientists analyze data from the other A-Train instruments. In return, other satellites will help validate its vital data.

"The A-Train constellation is an ideal measurement system for us," said Dave Crisp, the leader of the OCO-2 science team at NASA's Jet Propulsion Laboratory in Pasadena, California.

OCO-2 will fly along the same path as NASA satellites CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) and CloudSat, which monitor minute particles in the atmosphere called aerosols, and clouds, respectively. "We've lined up the ground tracks of OCO-2, CALIPSO and CloudSat almost perfectly, and we're hoping to keep them well aligned for as long as possible during the missions, so we can do the science we want with measurements from all three satellites," Crisp said.

OCO-2 measures carbon dioxide by observing its effect on sunlight. Sunlight is made up of waves of many lengths, or frequencies, some visible and others invisible. As sunlight passes through the atmosphere, carbon dioxide and other molecules absorb specific frequencies in the spectrum of light, leaving dark, narrow gaps in the spectrum. The more light that has been absorbed in a certain column of air, the more carbon dioxide is present there. In some cases, this may suggest that Earth's surface beneath that air contains a source of carbon dioxide, like a large industrial city. Less carbon dioxide implies a "sink," which absorbs carbon dioxide, like a thick forest during the growing season.

The OCO-2 spacecraft carries a single instrument composed of three spectrometers that measure different regions of the spectrum of light. One of these spectrometers observes the spectrum of molecular oxygen, referred to as the A-band spectrum. This is important because molecular oxygen is a relatively constant fraction of the atmosphere and can be used as a reference for measurements of other atmospheric gases, such as carbon dioxide. In addition to being critical for calibrating the carbon dioxide concentrations, it also tells scientists how much sunlight is absorbed or reflected by the aerosols and clouds, features that CALIPSO and CloudSat observe.

"If we combine the A-band spectrometer's measurements with information on aerosols and clouds from CALIPSO and CloudSat, we can use that information to estimate the amount of absorption of sunlight by these airborne particles, which is something we cannot currently do," said Dave Winker, principal investigator for the CALIPSO mission.

CloudSat and CALIPSO also help clarify OCO-2's data. The observatory uses its A-band spectrometer to find out how far sunlight has traveled before it reaches the satellite (its optical path) -- vital information for finding sources and sinks. A tiny mistake in the path-length measurement can introduce serious errors in the satellite's carbon dioxide measurements. Often clouds and aerosols in Earth's atmosphere reflect some sunlight back toward space before it reaches the surface, shortening sunlight's path and confusing the spectrometer about the distance to Earth. But CALIPSO and CloudSat's data about the location and height of aerosols and clouds can verify OCO-2's path-length measurements and determine what kept the sun from reaching Earth's surface.

"To check OCO-2's accuracy, we can compare it to CloudSat and CALIPSO. These measurements are synergistic," Crisp said.

Winker noted, "From OCO-2's point of view, CALIPSO is going to be very important in validating their measurement by correcting for cloud and aerosol effects. That these two satellites are flying together is a key part of the mission."

The A-Train's other satellites support OCO-2's work, too. MODIS (Moderate Resolution Imaging Spectroradiometer), an instrument on the Aqua satellite, tracks cloud cover. AIRS (Atmospheric Infrared Sounder), another Aqua instrument, measures air temperature and the amount of water content in the atmosphere. To accurately measure carbon dioxide, scientists must know all those details.

"We have the platforms that can tell us about water vapor and temperature, as well as clouds from the CloudSat satellite, the CALIPSO satellite, the AIRS instrument, and the MODIS instrument. This is the right place to fly OCO-2," Crisp said.

For more information about OCO-2, visit these sites:

http://www.nasa.gov/oco2

http://oco.jpl.nasa.gov

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

For more information about NASA's Earth science activities in 2014, visit:

http://www.nasa.gov/earthrightnow

Alan Buis

818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.Buis@jpl.nasa.gov


Written by Rosalie Murphy

JPL Earth Science and Technology Directorate


2014-219
Posted by Nelio Inacio at 7:29 AM 0 comments

Newfound Frozen World Orbits in Binary Star System

Newfound Frozen World Orbits in Binary Star System:

Planet with Twin Parent Stars
This artist's rendering shows a newly discovered planet (far right) orbiting one star (right) of a binary star system. The discovery, made by a collaboration of international research teams and led by researchers at The Ohio State University, expands astronomers' notions of where to look for planets in our galaxy. The research was funded in part by NASA. Image credit: Cheongho Han, Chungbuk National University, Republic of Korea
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July 03, 2014

A newly discovered planet in a binary, or twin, star system located 3,000 light-years from Earth is expanding astronomers' notions of where Earth-like -- and even potentially habitable -- planets can form, and how to find them.

At twice the mass of Earth, the planet orbits one of the stars in the binary system at almost exactly the same distance at which Earth orbits the sun. However, because the planet's host star is much dimmer than the sun, the planet is much colder than Earth -- a little colder, in fact, than Jupiter's icy moon Europa.

Four international research teams, led by professor Andrew Gould of The Ohio State University in Columbus, published their discovery in the July 4 issue of the journal Science. The research is partly funded by NASA.

The study provides the first evidence that terrestrial planets can form in orbits similar to Earth's, even in a binary star system where the stars are not very far apart. Although this planet itself is too cold to be habitable, the same planet orbiting a sun-like star in such a binary system would be in the so-called "habitable zone" -- the region where conditions might be right for life.

"This greatly expands the potential locations to discover habitable planets in the future," said Scott Gaudi, professor of astronomy at Ohio State. "Half the stars in the galaxy are in binary systems. We had no idea if Earth-like planets in Earth-like orbits could even form in these systems."

Earlier evidence that planets form in binary star systems came from NASA's Kepler and Spitzer space telescopes (see http://www.nasa.gov/centers/ames/news/releases/2011/11-69AR.html and http://www.nasa.gov/mission_pages/spitzer/news/spitzer-20070329.html), but the planets and dust structures in those studies were not similar to those of Earth.

The technique astronomers use to find the planet, called OGLE-2013-BLG-0341LBb, is called gravitational microlensing. In this method, the light of a distant star is magnified by a closer star that happens to pass in front -- if a planet is also present around the foreground star, it will further alter and distort the light of the background star. The telescopes used in this study are part of several projects, including the OGLE (Optical Gravitational Lensing Experiment), MOA (Microlensing Observations in Astrophysics), MicroFUN (the Microlensing Follow Up Network), and the Wise Observatory.

Searching for planets within binary systems is tricky for most techniques, because the light from the second star complicates the interpretation of the data. "But in gravitational microlensing," Gould explained, "we don't even look at the light from the star-planet system. We just observe how its gravity affects light from a more distant, unrelated star. This gives us a new tool to search for planets in binary star systems."

NASA's proposed WFIRST-AFTA (Wide-Field Infrared Survey Telescope - Astrophysics Focused Telescope Assets) mission would use the microlensing technique to find and characterize hundreds of thousands of planets in binary systems.

Read the full news release from Ohio State at:

http://news.osu.edu/news/2014/07/03/planet-discovery-expands-search-for-earthlike-planets/

Whitney Clavin

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-4673

whitney.clavin@jpl.nasa.gov



2014-222
Posted by Nelio Inacio at 7:28 AM 0 comments

NASA's RapidScat to Unveil Hidden Cycles of Sea Winds

NASA's RapidScat to Unveil Hidden Cycles of Sea Winds:

Hurricane Katrina in the Gulf of Mexico
A 2005 image of Hurricane Katrina in the Gulf of Mexico from NASA's QuikScat scatterometer shows the kind of ocean-wind data that ISS-RapidScat will provide. In this image, the highest wind speeds are shown in purple and barbs indicate wind direction. Image credit: NASA/JPL-Caltech
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July 07, 2014

Ocean waves, the hot sun, sea breezes -- the right combination makes a great day at the beach. A different combination makes a killer hurricane. The complex interactions of the ocean and the air above it that can create such different outcomes are not yet fully known. Scientists would especially like to understand the role that the daily heat of the sun plays in creating winds.

In a few months, NASA will send an ocean wind-monitoring instrument to a berth on the International Space Station. That unique vantage point will give ISS-RapidScat, short for the International Space Station Rapid Scatterometer, the ability to observe daily (also called diurnal) cycles of wind created by solar heat.

Winds contribute to motion in the ocean on every scale, from individual waves to currents extending thousands of miles. They affect local weather as well as large-scale, long-term climate patterns such as El Niño. Across the tropical Pacific, winds help or hinder local economies by allowing nutrient-rich water to well up from the ocean depths, nourishing marine life to the benefit of coastal fisheries, or blocking its upwelling.

Since the hours of daylight are totally predictable, you might expect their influence on winds to be equally obvious. But that's not the case. According to Sarah Gille, an oceanographer at Scripps Institution of Oceanography, San Diego, "There's an enormous amount of diurnal wind variation between 30 degrees north and south of the equator, and we don't understand the timing. It's clear that the winds aren't just triggered every day at noon [when the sun is highest]."

Scatterometer observations from satellites have proven invaluable for understanding ocean winds. A scatterometer is a type of radar that bounces microwaves off Earth's surface and measures the strength and direction of return signals. The more uneven the surface, the stronger the return signals. On the ocean, higher winds create larger waves and therefore stronger return signals. The return signal also tells scientists the direction of the wind, because waves line up in the direction the wind is blowing.

The reason spaceborne scatterometers haven't helped much with the specific question of daily wind cycles has to do with their orbits. All modern instruments have been in sun-synchronous orbits, in which a satellite is always oriented at the same angle relative to the sun. In this type of orbit, a satellite passes over every location at the same fixed times, for example, 6 a.m. and 6 p.m. over the equator. The resulting data can't throw much light on the question of how winds develop over the course of a day.

For six months in 2003, there were two scatterometers of the same type in space, collecting data at different times of day. From that data, Gille and her colleagues were able to recognize some patterns. "We could see, for example, how sea breezes converge over a large body of water like the Mediterranean or Black Sea. It was a nice window into diurnal variability, but we only had six months of data." That's inadequate to observe differences between summer and winter patterns, among other things.

In its berth on the space station, the two-year RapidScat mission, built and managed by NASA's Jet Propulsion Laboratory, Pasadena, California, will be the first modern spaceborne scatterometer not locked in a sun-synchronous orbit. Each time the space station passes over a spot on Earth, it's at a different time of day than on the previous visit.

RapidScat came into being because in 2009, NASA's previous scatterometer mission, an instrument called SeaWinds on the QuikScat satellite, stopped collecting ocean wind data following more than a decade of faithful service. Its antenna rotation mechanism wore out and stopped working. While the SeaWinds instrument itself is still functioning, its view is limited to a very narrow beam.

During QuikScat's decade of full operation, the National Weather Service, National Hurricane Center, U.S. Navy, and other users relied on its data (among other data sources) to produce forecasts and warnings of everything from El Niño to hurricanes to iceberg movements. "When QuikScat stopped spinning, the user community began looking at ways to get a scatterometer going again," said Stacey Boland, a RapidScat project systems engineer at JPL.

In 2012, NASA's space station program manager offered scientists at JPL a berth for a replacement scatterometer and a free ride into space in 2014 on a scheduled commercial cargo mission to resupply the space station. "The community had extensively evaluated many types of opportunities and was well aware of the benefit of the space station orbit," Boland said.

The entire instrument has been designed and built in the two years since then -- hence the adjective "Rapid" in its name. RapidScat's instrument is essentially the same as the durable SeaWinds instrument on QuikScat. RapidScat will give QuikScat's user community the same vital data, and eventually it will supply the long-awaited answers on diurnal winds.

Boland explained how the RapidScat data will accumulate to provide those answers. "We get near-complete spatial coverage every two days over the range of latitudes observable from the space station." (The station orbit ranges from 51.6 degrees north to 51.6 degrees south.) "The coverage at any particular spot is at a slightly different local time of day on each orbit. In about two months, we will have sampled 24 hours of local time at each spot."

Once RapidScat has gathered enough cycles of observations, Gille said, "When we average the data, it will tell us what the average conditions are and how much of the observed wind looks like a diurnal pattern."

Gille added, "We're very interested in putting time into an analysis to understand how diurnal winds change from season to season or year to year. Understanding the variability of these processes is a critical part of understanding weather."

For more information about ISS-RapidScat, visit:

http://winds.jpl.nasa.gov/missions/RapidScat/

RapidScat is the third of five NASA Earth science missions scheduled to be launched this year, the most new NASA Earth-observing mission launches in the same year in more than a decade. NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet. For more information about NASA's Earth science activities in 2014, visit:

http://www.nasa.gov/earthrightnow

Alan Buis

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-0474

alan.buis@jpl.nasa.gov


Steve Cole

NASA Headquarters, Washington

202-358-0918

stephen.e.cole@nasa.gov


Written by Carol Rasmussen

NASA Earth Science News Team


2014-223
Posted by Nelio Inacio at 7:28 AM 0 comments

Sun Sends More 'Tsunami Waves' to Voyager 1

Sun Sends More 'Tsunami Waves' to Voyager 1:

This artist's concept shows the Voyager 1 spacecraft entering the space between stars.
The Space Between: This artist's concept shows the Voyager 1 spacecraft entering the space between stars. Interstellar space is dominated by plasma, ionized gas (illustrated here as brownish haze), that was thrown off by giant stars millions of years ago. Image credit: NASA/JPL-Caltech
› Full image and caption


July 07, 2014

NASA's Voyager 1 spacecraft has experienced a new "tsunami wave" from the sun as it sails through interstellar space. Such waves are what led scientists to the conclusion, in the fall of 2013, that Voyager had indeed left our sun's bubble, entering a new frontier.

"Normally, interstellar space is like a quiet lake," said Ed Stone of the California Institute of Technology in Pasadena, California, the mission's project scientist since 1972. "But when our sun has a burst, it sends a shock wave outward that reaches Voyager about a year later. The wave causes the plasma surrounding the spacecraft to sing."

Data from this newest tsunami wave generated by our sun confirm that Voyager is in interstellar space -- a region between the stars filled with a thin soup of charged particles, also known as plasma. The mission has not left the solar system -- it has yet to reach a final halo of comets surrounding our sun -- but it broke through the wind-blown bubble, or heliosphere, encasing our sun. Voyager is the farthest human-made probe from Earth, and the first to enter the vast sea between stars.

"All is not quiet around Voyager," said Don Gurnett of the University of Iowa, Iowa City, the principal investigator of the plasma wave instrument on Voyager, which collected the definitive evidence that Voyager 1 had left the sun's heliosphere. "We're excited to analyze these new data. So far, we can say that it confirms we are in interstellar space."

Our sun goes through periods of increased activity, where it explosively ejects material from its surface, flinging it outward. These events, called coronal mass ejections, generate shock, or pressure, waves. Three such waves have reached Voyager 1 since it entered interstellar space in 2012. The first was too small to be noticed when it occurred and was only discovered later, but the second was clearly registered by the spacecraft's cosmic ray instrument in March of 2013.

Cosmic rays are energetic charged particles that come from nearby stars in the Milky Way galaxy. The sun's shock waves push these particles around like buoys in a tsunami. Data from the cosmic ray instrument tell researchers that a shock wave from the sun has hit.

Meanwhile, another instrument on Voyager registers the shock waves, too. The plasma wave instrument can detect oscillations of the plasma electrons.

"The tsunami wave rings the plasma like a bell," said Stone. "While the plasma wave instrument lets us measure the frequency of this ringing, the cosmic ray instrument reveals what struck the bell -- the shock wave from the sun."

This ringing of the plasma bell is what led to the key evidence showing Voyager had entered interstellar space. Because denser plasma oscillates faster, the team was able to figure out the density of the plasma. In 2013, thanks to the second tsunami wave, the team acquired evidence that Voyager had been flying for more than a year through plasma that was 40 times denser than measured before -- a telltale indicator of interstellar space.

Why is it denser out there? The sun's winds blow a bubble around it, pushing out against denser matter from other stars.

Now, the team has new readings from a third wave from the sun, first registered in March of this year. These data show that the density of the plasma is similar to what was measured previously, confirming the spacecraft is in interstellar space. Thanks to our sun's rumblings, Voyager has the opportunity to listen to the singing of interstellar space -- an otherwise silent place.

Voyager 1 and its twin, Voyager 2, were launched 16 days apart in 1977. Both spacecraft flew by Jupiter and Saturn. Voyager 2 also flew by Uranus and Neptune. Voyager 2, launched before Voyager 1, is the longest continuously operated spacecraft and is expected to enter interstellar space in a few years.

JPL, a division of Caltech, built and operates the twin Voyager spacecraft. The Voyagers Interstellar Mission is a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of NASA's Science Mission Directorate in Washington. NASA's Deep Space Network, managed by JPL, 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. The spacecraft's nuclear batteries were provided by the Department of Energy.

For more information on the Voyager mission, visit: http://voyager.jpl.nasa.gov

Whitney Clavin (818) 354-4673

Jet Propulsion Laboratory, Pasadena, Calif.

whitney.clavin@jpl.nasa.gov


2014-221
Posted by Nelio Inacio at 7:28 AM 0 comments

Four JPL Suborbital Technology Payloads Chosen

Four JPL Suborbital Technology Payloads Chosen:

This artist's concept shows a robot with legs that have microspine grippers
This artist's concept shows a robot with legs that have microspine grippers, which could potentially explore a rocky surface, such as an asteroid, in microgravity. Image credit: NASA/JPL-Caltech
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July 10, 2014

From hopping/tumbling robots to gecko-inspired adhesives, a variety of technologies have been chosen by NASA for flight on commercial reusable launch vehicles and a commercial parabolic aircraft. The selections were made through NASA's Flight Opportunities Program. The program gives these 13 space technology payloads, including four from NASA's Jet Propulsion Laboratory, Pasadena, California, a chance to be tested before they are used in the harsh environment of space.

Including this latest selection, there have been 138 technologies selected for test flights facilitated by the Flight Opportunities Program of NASA's Space Technology Mission Directorate.

Parabolic aircraft flights will allow 11 of the new payloads to experience brief periods of weightlessness. The other two projects will fly on suborbital reusable launch vehicle test flights. The flights are expected to take place in 2014 and 2015.

The selected proposals requested flights on Zero-G Corporation's Boeing 727 parabolic flight aircraft, UP Aerospace's Space-Loft rocket and Masten Space Systems' Xombie vertical takeoff/vertical landing rocket.

Three of the JPL-led payloads will fly on the parabolic aircraft and one will go up on the suborbital reusable launch vehicle.

The payloads selected for parabolic aircraft flights are:

From JPL:

-- "Validating Microgravity Mobility Models for Hopping/Tumbling Robots," Principal Investigator (PI) Issa Nesnas

-- "Microgravity Rock Coring Drill Using Microspines" and "Gecko Adhesive Grippers in Microgravity," PI Aaron Parness

From other institutions:

-- "Reduced Gravity Flight Demo of SPHERES Universal Docking Ports" and "Reduced Gravity Flight Demonstration of SPHERES INSPECT," PI Alvar Saenz Otero of Massachusetts Institute of Technology in Cambridge, Massachusetts

-- "Reinventing the Wheel: Parabolic Flight Validation of Reaction Spheres," PI Alvin Yew of NASA¹s Goddard Space Flight Center in Greenbelt, Maryland

-- "Enhanced Dynamic Load Sensors for ISS Operational Feasibility for Advanced Resistive Exercise Device," PI Christopher Krebs of Aurora Flight Sciences Corp. in Manassas, Virginia

-- "Effects of Microgravity on Intracranial Pressure," PI Benjamin Levine of University of Texas Southwestern Medical Center in Dallas

-- "Noninvasive Hemodynamic Monitoring in Microgravity Phase II (Arterial Stiffness)," PI Gregory Kovacs of Stanford University in Stanford, California

-- "Payloads Separation Performance of a 6U CubeSat Canisterized Satellite Dispenser," PI Hans-Peter Dumm of the United States Air Force Space Vehicles Directorate in Albuquerque, New Mexico

-- "Dragon V2 Propellant Management Device Microgravity Testing," PI Robin Titus of Space Exploration Technologies Corp., (SpaceX) in Hawthorne, California

The payloads selected for flight on a suborbital reusable launch vehicle are:

From JPL:

-- "Fuel Optimal and Accurate Landing Systems Test Flights," PI Andrew Johnson

From Purdue University:

-- "Zero-gravity Green Propellant Management Technology," PI Steven Collicott of Purdue University in Lafayette, Indiana

NASA manages the Flight Opportunities manifest, matching payloads with flights, and will pay for payload integration and the flight costs for the selected payloads. No funds are provided for the development of these payloads.

The Flight Opportunities Program, part of NASA's Space Technology Mission Directorate, is managed at NASA's Armstrong Flight Research Center at Edwards, California. NASA's Ames Research Center at Moffett Field, California, manages the solicitation and selection of technologies to be tested and demonstrated on commercial flight vehicles.

For more information on the Flight Opportunities program, visit:

http://flightopportunities.nasa.gov

Elizabeth Landau

818-354-6425

Jet Propulsion Laboratory, Pasadena, Calif.

elizabeth.landau@jpl.nasa.gov


Rachel Hoover

Ames Research Center, Moffett Field, Calif.

650-930-6149

rachel.hoover@nasa.gov


Leslie Williams

Armstrong Flight Research Center, Edwards, Calif.

661-276-3893

leslie.a.williams@nasa.gov


2014-225
Posted by Nelio Inacio at 7:27 AM 0 comments

Leading Space Experts to Discuss the Search for Life Beyond Earth

Leading Space Experts to Discuss the Search for Life Beyond Earth:

Kepler-186f, the first Earth-size Planet in the Habitable Zone
Leading Space Experts to Discuss the Search for Life Beyond Earth
The artist's concept depicts Kepler-186f , the first validated Earth-size planet to orbit a distant star in the habitable zone-a range of distance from a star where liquid water might pool on the planet's surface. Image credit: NASA
› Full image and caption


July 10, 2014

NASA Television will air a panel discussion of leading science and engineering experts on Monday, July 14, from 11 a.m. to 12:30 p.m. PDT (2 to 3:30 p.m. EDT), who will describe the scientific and technological roadmap that will lead to the discovery of potentially habitable worlds among the stars.

The event will take place at NASA Headquarters in Washington.

Space and ground observatories are cataloging and characterizing hundreds, and what is expected to eventually be thousands, of potentially habitable worlds in our galaxy. NASA space-based observatories are making unprecedented new discoveries. The agency's next step, the James Webb Space Telescope (JWST), will continue to help scientists rewrite scientific textbooks after its scheduled launch in 2018.

NASA Administrator Charlie Bolden will provide opening comments.

Panel participants include:

--Ellen Stofan, NASA chief scientist, NASA Headquarters, Washington

--John Grunsfeld, astronaut and associate administrator, NASA Science Mission Directorate, Washington

--John Mather, Nobel Laureate and Senior Project Scientist for JWST, NASA Goddard Space Flight Center, Greenbelt, Maryland

--Sara Seager, MacArthur Fellow and Professor of Planetary Science and Physics at the Massachusetts Institute of Technology, Cambridge

--Dave Gallagher, director for Astronomy and Physics, NASA's Jet Propulsion Laboratory, Pasadena, California

--Matt Mountain, director of the Space Telescope Science Institute, Baltimore and Telescope Scientist for JWST

Questions can be asked during the event by attendees or via Twitter using the hashtag #AskNASA.

For NASA TV streaming video, schedules and downlink information, visit: http://www.nasa.gov/nasatv

For more information about NASA's role in the search for life, visit: http://www.nasa.gov

Whitney Clavin

Jet Propulsion Laboratory, Pasadena, California

818-354-4673

whitney.clavin@jpl.nasa.gov


Dwayne Brown

NASA Headquarters, Washington

202-358-1726

dwayne.c.brown@nasa.gov


2014-227
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NASA Honors First Moon Landing, Looks Ahead to Mars

NASA Honors First Moon Landing, Looks Ahead to Mars:

Artist's concept image of a boot print on the moon and on Mars.
Artist's concept image of a boot print on the moon and on Mars.
Image Credit: NASA

› Larger image


July 15, 2014

NASA marks the 45th anniversary of the first moon landing this month while it takes the steps needed for America's next giant leap to send astronauts to Mars.

NASA's Apollo 11 crew landed on the moon July 20, 1969. The world watched 45 years ago as astronauts Neil Armstrong and Buzz Aldrin set their lunar module, Eagle, down in the Sea of Tranquility, while crewmate Michael Collins orbited above in the command module Columbia.

The agency will commemorate Armstrong's "one giant leap for mankind" through a number of events across, and above, the United States during the next two weeks, as well as on the agency's website and NASA Television.

On Friday, July 18 at 10:30 a.m. PDT (1:30 p.m. EDT), NASA TV will air a live conversation about the future of space exploration with actor, director and narrator Morgan Freeman. He will speak at NASA's Jet Propulsion Laboratory in Pasadena, California, about his personal vision for space. The event also will include NASA astronaut Reid Wiseman participating from the International Space Station.

Also on Friday at 3:30 p.m. EDT, NASA will host a discussion with Buzz Aldrin and astronaut Mike Massimino at the Intrepid Sea, Air & Space Museum in New York during the Intrepid Space and Science Festival. NASA also will have exhibits and activities at the festival Thursday, July 17 through Saturday, July 19. For more information about the festival, visit:

http://www.intrepidmuseum.org/SpaceandScienceFestival.aspx

On Sunday, July 20 at 7:39 p.m. PDT (10:39 p.m. EDT), when Armstrong opened the spacecraft hatch to begin the first spacewalk on the moon, NASA TV will replay the restored footage of Armstrong and Aldrin's historic steps on the lunar surface.

On Monday, July 21 at 7 a.m. PDT (10 a.m. EDT) from the agency's Kennedy Space Center in Florida, NASA TV will air live coverage of the renaming of the center's Operations and Checkout Building in honor of Armstrong, who passed away in 2012. The renaming ceremony will include NASA Administrator Charles Bolden, Kennedy Center Director Robert Cabana, Apollo 11's Collins, Aldrin and astronaut Jim Lovell, who was the mission's back-up commander. International Space Station NASA astronauts Wiseman and Steve Swanson, who is the current station commander, also will take part in the ceremony from their orbiting laboratory 260 miles above Earth.

Kennedy's Operations and Checkout Building has played a vital role in NASA's spaceflight history. It was used during the Apollo program to process and test the command, service and lunar modules. Today, the facility is being used to process and assemble NASA's Orion spacecraft, which the agency will use to send astronauts to an asteroid in the 2020s and Mars in the 2030s.

On Thursday, July 24 at 3 p.m. PDT (6 p.m. EDT), which is the 45th anniversary of Apollo 11's return to Earth, the agency will host a panel discussion -- called NASA's Next Giant Leap -- from Comic-Con International in San Diego. Moderated by actor Seth Green, the panel includes Aldrin, NASA Planetary Science Division Director Jim Green, JPL systems engineer Bobak Ferdowsi, and NASA astronaut Mike Fincke, who will talk about Orion and the Space Launch System rocket, which will carry humans on America's next great adventure in space.

The NASA.gov website will host features, videos, and historic images and audio clips that highlight the Apollo 11 anniversary, as well as the future of human spaceflight. To explore all the special content, visit:

http://www.nasa.gov/apollo45

To join the ongoing conversation on social media about the anniversary and NASA's deep space exploration plans, use the hashtags #NextGiantLeap and #Apollo45.

For NASA TV streaming video, downlink and scheduling information, visit:

http://www.nasa.gov/nasatv

For information about the activities, planning and preparations for the next giant leap in space exploration, visit:

http://www.nasa.gov/exploration

Veronica McGregor

Jet Propulsion Laboratory, Pasadena, California

818-354-0880

veronica.mcgregor@jpl.nasa.gov


David Weaver/Bob Jacobs

NASA Headquarters, Washington

202-358-1600

david.s.weaver@nasa.gov / bob.jacobs@nasa.gov


2014-229
Posted by Nelio Inacio at 7:24 AM 0 comments

Looking Back at the Jupiter Crash 20 Years Later

Looking Back at the Jupiter Crash 20 Years Later:

NASA's Galileo spacecraft captured these four views of Jupiter as the last of Comet Shoemaker-Levy 9's large fragments struck the planet.
NASA's Galileo spacecraft captured these four views of Jupiter as the last of comet Shoemaker-Levy 9's large fragments struck the planet. Image credit: NASA/JPL-Caltech
› Full image and caption


July 15, 2014

Twenty years ago, human and robotic eyes observed the first recorded impact between cosmic bodies in the solar system, as fragments of comet Shoemaker-Levy 9 slammed into the atmosphere of Jupiter. Between July 16 and July 22, 1994, space- and Earth-based assets managed by NASA's Jet Propulsion Laboratory in Pasadena, California, joined an armada of other NASA and international telescopes, straining to get a glimpse of the historic event:

- NASA's Galileo spacecraft, still a year-and-a-half out from its arrival at Jupiter, had a unique view of fireballs that erupted from Jupiter's southern hemisphere as the comet fragments struck.

- NASA's Hubble Space Telescope, using the JPL-developed and -built Wide Field and Planetary Camera 2, observed the comet and the impact scars it left on Jupiter.

- The giant radio telescopes of NASA's Deep Space Network -- which perform radio and radar astronomy research in addition to their communications functions -- were tasked with observing radio emissions from Jupiter's radiation belt, looking for disturbances caused by comet dust.

- NASA's Voyager 2 spacecraft, then about 3.7 billion miles (6 billion kilometers) from Jupiter, observed the impacts with its ultraviolet spectrometer and a planetary radio astronomy instrument.

- The Ulysses spacecraft also made observations during the comet impact from about 500 million miles (800 million kilometers) away. Ulysses observed radio transmissions from Jupiter with its combined radio wave and plasma wave instrument.

The work of scientists in studying the Shoemaker-Levy 9 impact raised awareness about the potential for asteroid impacts on Earth and the need for predicting them ahead of time, important factors in the formation of NASA's Near-Earth Object Program Office. The NEO Program Office coordinates NASA-sponsored efforts to detect, track and characterize potentially hazardous asteroids and comets that could approach Earth.

The Galileo mission was managed by NASA's Jet Propulsion Laboratory in Pasadena, California, for the agency's Science Mission Directorate. JPL also manages the Voyager mission and the Deep Space Network for NASA. NASA's Near-Earth Object Program at NASA Headquarters, Washington, manages and funds the search, study and monitoring of asteroids and comets whose orbits periodically bring them close to Earth. JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology, Pasadena.

For more information about the Shoemaker-Levy 9 impact, visit: http://solarsystem.nasa.gov/planets/profile.cfm?Object=Com_PShoemakerLevy9

Preston Dyches

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-7013

preston.dyches@jpl.nasa.gov


2014-231
Posted by Nelio Inacio at 7:24 AM 0 comments

NASA Rover's Images Show Laser Flash on Martian Rock

NASA Rover's Images Show Laser Flash on Martian Rock:

First Imaging of Laser-Induced Spark on Mars
NASA's Curiosity Mars rover used the Mars Hand Lens Imager (MAHLI) camera on its arm to catch the first images of sparks produced by the rover's laser being shot at a rock on Mars. Credit: NASA/JPL-Caltech/MSSS
› Full image and caption


July 16, 2014

Flashes appear on a baseball-size Martian rock in a series of images taken Saturday, July 12 by the Mars Hand Lens Imager (MAHLI) camera on the arm of NASA's Curiosity Mars Rover. The flashes occurred while the rover's Chemistry and Camera (ChemCam) instrument fired multiple laser shots to investigate the rock's composition.

The images, strung together as a video, are available online at:

http://www.jpl.nasa.gov/video/?id=1317

ChemCam's laser has zapped more than 600 rock and soil targets on Mars since Curiosity landed in the planet's Gale Crater in August 2012.

"This is so exciting! The ChemCam laser has fired more than 150,000 times on Mars, but this is the first time we see the plasma plume that is created," said ChemCam Deputy Principal Investigator Sylvestre Maurice, at the Research Institute in Astrophysics and Planetology, of France's National Center for Scientific Research and the University of Toulouse, France. "Each time the laser hits a target, the plasma light is caught and analyzed by ChemCam's spectrometers. What the new images add is confirmation that the size and shape of the spark are what we anticipated under Martian conditions."

Preliminary analysis of the ChemCam spectra from this target rock, appropriately named "Nova," indicates a composition rich in silicon, aluminum and sodium, beneath a dust layer poor in those elements. This is typical of rocks that Curiosity is encountering on its way toward Mount Sharp.

MAHLI Deputy Principal Investigator Aileen Yingst of the Planetary Science Institute, Tucson, Arizona, said, "One of the reasons we took these images is that they allow the ChemCam folks to compare the plume to those they imaged on Earth. Also, MAHLI has captured images of other activities of Curiosity, for documentation purposes, and this was an opportunity to document the laser in action."

Malin Space Science Systems, San Diego, developed, built and operates MAHLI. The U.S. Department of Energy's Los Alamos National Laboratory, in Los Alamos, New Mexico, developed ChemCam in partnership with scientists and engineers funded by the French national space agency (CNES), the University of Toulouse and France's National Center for Scientific Research.

NASA's Mars Science Laboratory Project is using Curiosity to assess ancient habitable environments and major changes in Martian environmental conditions. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, built the rover and manages the project for NASA's Science Mission Directorate in Washington.

For more information about Curiosity, visit these sites: http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/

You can follow the mission on Facebook at: http://www.facebook.com/marscuriosity and on Twitter at: http://www.twitter.com/marscuriosity

Guy Webster

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-6278

guy.webster@jpl.nasa.gov


2014-232
Posted by Nelio Inacio at 7:23 AM 0 comments

Ten-Year Endeavor: NASA's Aura Tracks Pollutants

Ten-Year Endeavor: NASA's Aura Tracks Pollutants:

The maps show the Antarctic ozone hole on September 16 in 2006 and 2011
The maps show the Antarctic ozone hole on September 16 in 2006 and 2011, the two years with the lowest ozone concentrations ever measured. They were made with data from the Ozone Monitoring Instrument on Aura. Image Credit: NASA's Earth Observatory

› Larger image


July 16, 2014

NASA's Aura satellite, celebrating its 10th anniversary on July 15, has provided vital data about the cause, concentrations and impact of major air pollutants. With instruments providing key measurements of various gases - including two built and managed by NASA's Jet Propulsion Laboratory: the Tropospheric Emission Spectrometer (TES) and Microwave Limb Sounder (MLS) -- Aura gives a comprehensive view of one of the most important parts of Earth -- the atmosphere.

Aura has improved our understanding of ozone, a versatile gas that both benefits and harms the atmosphere, depending on its location. Near the ground, ozone is a pollutant that damages plants and can decrease lung function in humans. Somewhat higher in the atmosphere, ozone affects climate as a greenhouse gas. Aura's TES instrument provides measurements of ozone and other greenhouse gases.

The majority of ozone, about 90 percent, is even higher -- in the stratosphere, 12 to 90 miles above the surface -- where it shields us from the sun's ultraviolet light and makes life possible on Earth. Over the Antarctic, cold temperatures and human-produced chlorine gases destroy ozone each spring. Scientists use Aura's Microwave Limb Sounder (MLS) instrument to measure ozone and other trace gases in and around the ozone hole every year. In 2006 and 2011, Aura's instruments revealed two of the largest and deepest ozone holes in the past decade, and also helped scientists understand the different causes of the two large holes.

Shortly after Aura's launch, the Ozone Monitoring Instrument (OMI) began monitoring levels of another major pollutant -- nitrogen dioxide. This brownish gas can lead to respiratory problems and is an ingredient in ground-level ozone pollution. OMI data show that nitrogen dioxide levels in the United States decreased 4 percent per year from 2005 to 2010, a time when stricter policies on power plant and vehicle emissions came into effect. As a result, concentrations of ground-level ozone also decreased. During the same period, global nitrogen dioxide levels increased a little over half a percent per year. China's level increased about 6 percent per year.

OMI also measures sulfur dioxide, a gas that combines with other chemicals in clouds to produce acid rain or reacts to form sulfate aerosols, which affect health and climate. OMI has identified large concentrations of sulfur dioxide around power plants and volcanoes.

Aura's decade of work has set the stage for future air quality monitoring instruments. The European Space Agency will be launching the follow-up TROPOspheric Monitoring Instrument, which will continue Aura's OMI measurements with better ground resolution and precision. NASA plans to launch the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument, which will observe ozone, nitrogen dioxide, sulfur dioxide, formaldehyde and aerosols over the United States, Canada and Mexico.

"Pollution is a global issue because it can travel long distances in the wind," said Anne Douglass, Aura project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "By using satellites, we can develop a valuable global inventory of pollutants and understand how air quality may be changing."

For more on Aura's 10-year contribution to atmospheric chemistry research, visit:

http://www.nasa.gov/content/goddard/ten-year-endeavor-nasa-s-aura-and-the-ozone-layer/

and

http://www.nasa.gov/content/goddard/ten-year-endeavor-nasa-s-aura-tracks-pollutants/

For more on TES, visit:

http://tes.jpl.nasa.gov/

For more on MLS, visit:

http://mls.jpl.nasa.gov/index-eos-mls.php

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

For more information about NASA's Earth science activities in 2014, visit:

http://www.nasa.gov/earthrightnow

Alan Buis

818-354-0474

Jet Propulsion Laboratory, Pasadena, Calif.

Alan.Buis@jpl.nasa.gov


Written by Kasha Patel

NASA Goddard Space Flight Center, Greenbelt, Md.


2014-233
Posted by Nelio Inacio at 7:22 AM 0 comments

Rosetta Spacecraft Approaching Twofold Comet

Rosetta Spacecraft Approaching Twofold Comet:

Rosetta Mission's Destination: Comet 67P/Churnyumov-Gerasimenko
The OSIRIS instrument on the European Space Agency's Rosetta spacecraft photographed the mission's destination comet on July 14, 2014, from about 7,500 miles away. The images show that comet 67P/Churyumov-Gerasimenko has a two-part shape. The version at right is enhanced with interpolated data. Credit: ESA/Rosetta/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
› Full image and caption


July 17, 2014

As the European Space Agency's spacecraft Rosetta is slowly approaching its destination, comet 67P/Churyumov-Gerasimenko, the comet is again proving to be full of surprises. New images obtained by OSIRIS, the onboard scientific imaging system, confirm the body's peculiar shape hinted at in earlier pictures. Comet 67P is obviously different from other comets visited so far.

"The distance still separating Rosetta from 67P is now far from astronomical," said OSIRIS Principal Investigator Holger Sierks from the Max Planck Institute for Solar System Research (MPS) in Germany. "It's a trip of less than 14,000 kilometers [about 8,700 miles]. That's comparable to traveling from Germany to Hawaii on a summer holiday."

However, while taking a snapshot of Mauna Kea, Hawaii's highest mountain, from Germany is an impossible feat, Rosetta's camera OSIRIS is doing a great job at catching ever clearer glimpses of its similarly sized destination. Images obtained on July 14 clearly show a tantalizing shape. The comet's nucleus consists of two distinctly separated parts.

"This is unlike any other comet we have ever seen before," said OSIRIS project manager Carsten Güttler from the MPS. "The images faintly remind me of a rubber ducky with a body and a head." How 67P received this intriguing shape is still unclear. "At this point we know too little about 67P to allow for more than an educated guess," said Sierks. In the next months, the scientists hope to determine more of the comet's physical and mineralogical properties. These could help them determine whether the comet's body and head were formerly two individual bodies.

In order to get an idea of what seems to be a very unique body, the observed image data can be interpolated to create a smoother shape. "There is, of course, still uncertainty in these processed, filtered images, and the surface will not be as smooth as it now appears," Güttler pointed out. "But they help us get a first idea."

Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta's Philae lander is provided by a consortium led by the German Aerospace Center, Cologne; Max Planck Institute for Solar System Research, Gottingen; French National Space Agency, Paris; and the Italian Space Agency, Rome. NASA's Jet Propulsion Laboratory, Pasadena, California, a division of the California Institute of Technology, Pasadena, manages the U.S. participation in the Rosetta mission for NASA's Science Mission Directorate in Washington. Rosetta carries three NASA instruments in its 21-instrument payload.

For more information on the U.S. instruments aboard Rosetta, visit:

http://rosetta.jpl.nasa.gov

More information about Rosetta is available at:

http://www.esa.int/rosetta

Guy Webster

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-6278

guy.webster@jpl.nasa.gov


Dwayne Brown

NASA Headquarters

202-358-1726

dwayne.c.brown@nasa.gov


Markus Bauer

European Space Agency, Noordwijk, Netherlands

011-31-71-565-6799

markus.bauer@esa.int


Birgit Krummheuer

Max Planck Institute for Solar System Research

011-49-551-384-979-462

krummheuer@mps.mpg.de


2014-234
Posted by Nelio Inacio at 7:21 AM 0 comments

A 10-Year Endeavor: NASA's Aura and Climate Change

A 10-Year Endeavor: NASA's Aura and Climate Change:

NASA's 10-year-old Aura satellite, which studies Earth's atmosphere
NASA's 10-year-old Aura satellite, which studies Earth's atmosphere, continues to help scientists understand Earth's changing climate.
Credit: NASA


› Larger image


July 17, 2014

Nitrogen and oxygen make up nearly 99 percent of Earth's atmosphere. The remaining one percent is comprised of gases that -- although present in small concentrations -- can have a big impact on life on Earth. Trace gases called greenhouse gases warm the surface, making it habitable for humans, plants and animals. But these greenhouse gases, as well as clouds and tiny particles called aerosols in the atmosphere, also play vital roles in Earth's complex climate system.

Celebrating its 10th anniversary this week, NASA's Aura satellite and its four onboard instruments measure some of the climate agents in the atmosphere, including greenhouse gases, clouds and dust particles. These global datasets provide clues that help scientists understand how Earth's climate has varied and how it will continue to change.

Measuring Greenhouse Gases

When the sun shines on Earth, some of the light reaches and warms the surface. The surface then radiates this heat back outward, and greenhouse gases stop some of the heat from escaping to space, keeping the surface warm. Greenhouse gases are necessary to keep Earth at a habitable temperature, but since the Industrial Revolution, greenhouse gases have increased substantially, causing an increase in temperature. Aura provides measurements of greenhouse gases such as ozone and water vapor, helping scientists understand the gases that influence climate.

People, plants and animals live in the lowest layer of the atmosphere, called the troposphere. In this layer, the temperature decreases with altitude, as mountain climbers experience. The temperature starts to increase again at the tropopause, about 8 miles (12.9 kilometers) above the surface at temperate latitudes, like those of the United States and Europe. Closer to the equator, the tropopause is about 11 miles (17.7 kilometers) from the surface.

In the middle and upper troposphere, ozone acts as a greenhouse gas, trapping heat in Earth's atmosphere. Tropospheric ozone is one of the most important human-influenced greenhouse gases.

Aura's Tropospheric Emission Spectrometer (TES) instrument, built and managed by NASA's Jet Propulsion Laboratory, Pasadena, California, delivers global maps showing annual averages of the heat absorbed by ozone, in particular in the mid troposphere. Using these maps and computer models, researchers learned that ozone trapped different amounts of heat in Earth's atmosphere depending on its geographic location. For instance, ozone appeared to be a more effective greenhouse gas over hotter regions like the tropics and cloud-free regions like the Middle East.

"If you want to understand climate change, you need to monitor the greenhouse gases and how they change over time," said Bryan Duncan, an atmospheric scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Along with ozone, Aura measures other important greenhouse gases such as methane, carbon dioxide and water vapor.

Improving Climate Models

In addition to greenhouse gases, Aura measures several other constituents relevant to climate -- smoke, dust and clouds including the ice particles within the clouds -- that are important for testing and improving climate models.

"If you don't have any data, then you don't know if the models are right or not," said Anne Douglass, Aura project scientist at Goddard. "The models can only be as good as your knowledge."

The way clouds affect Earth's climate depends on their altitude and latitude. Two of Aura's instruments have provided information about tropical clouds. Like greenhouse gases, high, thin clouds in the tropics absorb some of Earth's outgoing heat and warm the surface. Aura's High Resolution Dynamics Limb Sounder (HIRDLS) instrument provided global maps showing cirrus clouds in the upper altitudes in the tropics. Researchers have used these data along with data records from previous satellites going back to 1985 to show that the tropical cirrus cloud distribution has been steady, giving scientists information about the interplay among water vapor, ice and the life cycle of these clouds.

Aura's Microwave Limb Sounder (MLS) instrument, also built and managed by JPL, made the first global measurements of cloud ice content in the upper troposphere, providing new data input for climate models. MLS showed cloud ice is often present over warm oceans. Along with satellite rainfall data, MLS shows that dirty, polluted clouds rain less than clean clouds. The novel relationships obtained from HIRDLS and MLS connect ocean temperatures with clouds and ice and quantify effects of pollution on tropical rainfall -- which are important assessments for climate models.

Aerosols influence climate, but their influence is challenging to decipher because they play several different roles. Aerosols reflect radiation from the sun back into space; this tends to cool Earth's surface. Aerosols such as dust and smoke also absorb radiation and heat the atmosphere where they are concentrated. Aura's Ozone Monitoring Instrument (OMI) is especially good at observing these absorbing aerosols above clouds and bright deserts. Both OMI and TES also provide data on gases, such as sulfur dioxide and ammonia, which are primary ingredients for other types of less-absorbing aerosols. Aura data, in conjunction with other satellite data, are helping scientists understand how aerosols interact with incoming sunlight in Earth's atmosphere; this, in turn, helps scientists improve long-term predictions in climate models.

Learning from Long Data Sets

Researchers investigated how natural phenomena such as El Niño affect tropospheric ozone concentrations -- a study made possible by Aura's extensive data set.

El Niño is an irregularly occurring phenomenon associated with warm ocean currents near the Pacific coast of South America that changes the pattern of tropical rainfall. The occasional appearance of areas of warmer temperatures in the Pacific Ocean shifts the stormiest area from the west to the east; the region of upward motion -- a hallmark of low ozone concentrations over the ocean -- moves along with it.

Without a decade-long data record, researchers would not be able to conduct such a study. Using the extensive data set, researchers are able to separate the response of ozone concentrations to the changes in human activity, such as biomass burning, from its response to natural forcing such as El Niño.

"Studies like these that investigate how the composition of the troposphere responds to a natural variation are important for understanding how the Earth system will respond to other forcing, potentially including changes in climate," said Douglass. "The Earth system is complex, and Aura's breadth and the length of the composition data record help us to understand this important part of the system."

For more information on Aura, visit:

http://aura.gsfc.nasa.gov/

For more on TES, visit:

http://tes.jpl.nasa.gov/

For more on MLS, visit:

http://mls.jpl.nasa.gov/index-eos-mls.php

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

For more information about NASA's Earth science activities in 2014, visit:

http://www.nasa.gov/earthrightnow

Alan Buis

818-354-0474

Jet Propulsion Laboratory, Pasadena, California

Alan.buis@jpl.nasa.gov


Written by Kasha Patel

NASA Goddard Space Flight Center, Greenbelt, Maryland


2014-236
Posted by Nelio Inacio at 7:21 AM 0 comments

Wednesday, July 16, 2014

Colossal Hot Cloud Envelopes Colliding Galaxies

Colossal Hot Cloud Envelopes Colliding Galaxies:

NGC 6240

Scientists have used
Chandra to make a detailed study of an enormous cloud of hot gas
enveloping two large, colliding galaxies. This unusually large
reservoir of gas contains as much mass as 10 billion Suns, spans
about 300,000 light years, and radiates at a temperature of more
than 7 million degrees.

This giant gas cloud,
which scientists call a "halo," is located in the system called NGC
6240. Astronomers have long known that NGC 6240 is the site of the
merger of two large spiral galaxies similar in size to our own
Milky Way. Each galaxy contains a supermassive black hole at its
center. The black holes are spiraling toward one another, and may
eventually merge to form a larger black hole.

Another consequence of the collision between the galaxies
is that the gas contained in each individual galaxy has been
violently stirred up. This caused a baby boom of new stars that has
lasted for at least 200 million years. During this burst of stellar
birth, some of the most massive stars raced through their evolution
and exploded relatively quickly as supernovas.

The scientists involved with this study argue that this
rush of supernova explosions dispersed relatively high amounts of
important elements such as oxygen, neon, magnesium, and silicon
into the hot gas of the newly combined galaxies. According to the
researchers, the data suggest that this enriched gas has slowly
expanded into and mixed with cooler gas that was already
there.

During the extended baby boom, shorter
bursts of star formation have occurred. For example, the most
recent burst of star formation lasted for about five million years
and occurred about 20 million years ago in Earth's timeframe.
However, the authors do not think that the hot gas was produced
just by this shorter burst.

More at http://chandra.harvard.edu/photo/2013/ngc6240/

-Megan Watzke, CXC









Posted by Nelio Inacio at 4:16 PM 0 comments

NGC 2392: A Beautiful End to a Star’s Life

NGC 2392: A Beautiful End to a Star’s Life:

NGC 2392

Stars like the Sun can become remarkably photogenic at the end of their life. A good example is NGC 2392, which is located about 4,200 light years from Earth. NGC 2392, (nicknamed the "Eskimo Nebula") is what astronomers call a planetary nebula. This designation, however, is deceiving because planetary nebulae actually have nothing to do with planets. The term is simply a historic relic since these objects looked like planetary disks to astronomers in earlier times looking through small optical telescopes.

Instead, planetary nebulae form when a star uses up all of the hydrogen in its core -- an event our Sun will go through in about five billion years. When this happens, the star begins to cool and expand, increasing its radius by tens to hundreds of times its original size. Eventually, the outer layers of the star are carried away by a 50,000 kilometer per hour wind, leaving behind a hot core. This hot core has a surface temperature of about 50,000 degrees Celsius, and is ejecting its outer layers in a much faster wind traveling six million kilometers per hour. The radiation from the hot star and the interaction of its fast wind with the slower wind creates the complex and filamentary shell of a planetary nebula. Eventually the remnant star will collapse to form a white dwarf star.

More at http://chandra.harvard.edu/photo/2013/ngc2392/

-Megan Watzke, CXC









Posted by Nelio Inacio at 4:16 PM 0 comments

X-RAY WHISPERS IN A NOISY PUB

X-RAY WHISPERS IN A NOISY PUB:

We are delighted to welcome Katja Poppenhaeger as a guest blogger today. Katja is the first author of a new paper describing the first exoplanet transit ever seen in X-rays, the subject of our latest press release [URL to be added]. Katja studied physics at Frankfurt University in Germany, followed by a PhD in astrophysics at Hamburg Observatory in Germany, before coming to Harvard-Smithsonian Center for Astrophysics (CfA) as a postdoc. She will be a Sagan Fellow at CfA beginning in September 2013.

K.Poppenhaeger

Credit: K.Poppenhaeger
I remember when, back in grad school, my colleagues and I were watching the launch of the Kepler space telescope on the internet. We were really excited because this telescope would - and, in retrospect, has - discovered thousands of planet candidates around other stars, using the transit method. Back then I thought to myself, wouldn't it be cool if I could observe such a transit in X-rays? X-rays are absorbed high up in our Earth's atmosphere, which makes the Earth's X-ray radius about 100 km larger than its optical radius - that is about 1.5% in terms of extra radius. I wanted to use that effect to test how far the outer atmosphere of a Hot Jupiter extends. These Hot Jupiters orbit so close to their central star that they get heated up to temperatures over 1000 K, and their atmospheres can even boil away (which let me hope that there might be more than just an extra 1.5% in radius to find for such planets).

So the first thing I did was to check the data archives of the two big X-ray telescopes, Chandra and XMM-Newton, to see if someone had - by chance or on purpose - observed a planet-hosting star in X-rays while its planet was transiting in front of it. And I couldn't believe my luck: there was indeed a fifteen hour long observation of the star HD 189733 with XMM-Newton, and its Hot Jupiter HD 189733b was crossing in front of the star during that observation.

But when I looked at the light curve, I was rather disappointed: The star is magnetically active, meaning that its corona is bright and flickering, so its X-ray light curve showed lots of scatter. Looking for a transit signal in this light curve was like trying to hear a whisper in a noisy pub. But playing with the light curve for a bit, I realized that during the two hours of the observation where I knew the transit was happening, the X-ray signal was slightly weaker than before and after the transit. It might just have been luck, but I was determined: I had to get more data. With more transits that I could add up, the flickering of the corona would finally average out, and the transit signal would become clearer.

impression of the HD 189773

An artist's impression of the HD 189773 system, showing the Hot Jupiter transiting the star.
Credit: NASA/CXC/M.Weiss
So I applied for new observations and was granted time to observe six transits with the Chandra X-ray Observatory. When the data arrived, I combined the signal of all observations and was finally successful: I could detect the transit of the planet in X-rays. What surprised me was how deep the transit was: The planet swallowed about 6-8% of the X-ray light from the star, while it only blocked 2.4% of the starlight at optical wavelengths. That means that the planet's atmosphere blocks X-rays at altitudes of more than 60,000 km above its optical radius - a 75% larger radius in X-rays! That is pretty big, and I calculated that the outer atmosphere has to be heated up to about 20,000 K to sustain itself at such high altitudes. The bigger X-ray radius also means that the planet loses its atmosphere about 40% faster than thought before.

So what's next? I'd like to know if the X-ray radius of other hot exoplanets is extended as well - and if yes, does the extent depend on the heating of the planet by the host star, or more on things like the overall density of the planet? Together with my former colleagues from Hamburg Observatory, we will test this for the even hotter Jupiter CoRoT-2b, using XMM-Newton. Personally, I'd like it best if the CoRoT-2b experiment had a completely surprising outcome as well - we'll know next year!



Posted by Nelio Inacio at 4:15 PM 0 comments

Dwarf Galaxy Caught Ramming Into a Large Spiral

Dwarf Galaxy Caught Ramming Into a Large Spiral:

NGC 1232

Observations with NASA's Chandra X-ray Observatory have revealed a massive cloud of multimillion-degree gas in a galaxy about 60 million light years from Earth. The hot gas cloud is likely caused by a collision between a dwarf galaxy and a much larger galaxy called NGC 1232. If confirmed, this discovery would mark the first time such a collision has been detected only in X-rays, and could have implications for understanding how galaxies grow through similar collisions.


An image combining X-rays and optical light shows the scene of this collision. The impact between the dwarf galaxy and the spiral galaxy caused a shock wave - akin to a sonic boom on Earth - that generated hot gas with a temperature of about 6 million degrees. Chandra X-ray data, in purple, show the hot gas has a comet-like appearance, caused by the motion of the dwarf galaxy. Optical data from the European Southern Observatory's Very Large Telescope reveal the spiral galaxy in blue and white. X-ray point sources have been removed from this image to emphasize the diffuse emission.

More at http://chandra.harvard.edu/photo/2013/ngc1232/

-Megan Watzke, CXC







Posted by Nelio Inacio at 4:15 PM 0 comments
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