Aquarius Returns Global Maps of Soil Moisture

NASA - Aquarius / SAC-D Mission logo.

July 7, 2014

Scientists working with data from NASA's Aquarius instrument have released worldwide maps of soil moisture, showing how the wetness of the land fluctuates with the seasons and weather phenomena.

Soil moisture, the water contained within soil particles, is an important player in Earth's water cycle. It is essential for plant life and influences weather and climate. Satellite readings of soil moisture will help scientists better understand the climate system and have potential for a wide range of applications, from advancing climate models, weather forecasts, drought monitoring and flood prediction to informing water management decisions and aiding in predictions of agricultural productivity.

Aquarius Returns Global Maps of Soil Moisture

Video above: This animated version of Aquarius' measurements reveals a dynamic pattern of worldwide shifts between dry and moist soils. Video Credit: NASA's Goddard Space Flight Center.

Launched June 10, 2011, aboard the Argentinian spacecraft Aquarius/Satélite de Aplicaciones Científicas (SAC)-D, Aquarius was built to study the salt content of ocean surface waters. The new soil wetness measurements were not in the mission's primary science objectives, but a NASA-funded team led by U.S. Department of Agriculture (USDA) researchers has developed a method to retrieve soil moisture data from the instrument's microwave radiometer.

The Aquarius measurements are considerably coarser in spatial resolution than the measurements from the upcoming NASA Soil Moisture Active Passive (SMAP) mission, which was specifically designed to provide the highest quality soil moisture measurements available, including a spatial resolution 10 times that offered by Aquarius.

Soils naturally radiate microwaves and the Aquarius sensor can detect the microwave signal from the top 2 inches (5 centimeters) of the land, a signal that subtly varies with changes in the wetness of the soil. Aquarius takes eight days to complete each worldwide survey of soil moisture, although with gaps in mountainous or vegetated terrain where the microwave signal becomes difficult to interpret.

Image above: This image shows what the soil moisture conditions around the planet were like in August 2013: dry areas are represented in the brown scale, while wetter areas are in blue and green. Image Credit: NASA Goddard's Science Visualization Studio/T. Schindler.

Tom Jackson, principal investigator for the Aquarius soil moisture measurements and a hydrologist with USDA, said that his agency uses soil wetness information to improve crop forecasts. These forecasts not only help farmers and markets adjust their prices according to worldwide production, but also allow relief agencies to plan for food emergency responses.

"There's a lot of precipitation data in our country, but outside the U.S. and Europe it gets pretty sparse," said Jackson. "By using soil moisture readings, we can better monitor the condition of soils."

An animated version of Aquarius' soil moisture measurements reveals a dynamic pattern of worldwide shifts between dry and moist soils. A look at the Eastern coast of Australia during late January and early February 2012 shows the impact of Cyclone Jasmine, a tropical storm that brought heavy rainfall to northern Queensland. In Africa, a wide band of wet soils that matches the rain belt travels north of the equator in the Southern Hemisphere’s winter and then moves south as summer progresses. The land-soaking effects of the monsoon are evident in the Indian subcontinent from June to October. The U.S. Midwest dramatically shifts from being bone-dry during the 2012 drought to waterlogged during the floods of April and May 2013.

Animation above: This visualization shows soil moisture measurements taken by NASA’s Aquarius instrument. Here, soil moisture in the top 2 inches of the land is visible. Image Credit: NASA Goddard's Science Visualization Studio/T. Schindler.

But Aquarius has some limitations in its soil moisture estimates, said USDA’s Rajat Bindlish, a co-investigator on the soil moisture maps. The instrument's 62-mile-wide (100-km) footprint prevents it from covering small islands, coastlines and any piece of land narrower than 62 miles, such as Baja California or Italy. Other factors interfere with soil moisture retrievals, too: The dense tree canopy of the Amazon rainforest distorts the microwave signal while snow and ice block it. These areas where the microwave signals are difficult to interpret are shown in dark gray in the Aquarius soil moisture animation.

NASA's Aquarius Satellite Maps Earth's Soil Moisture. Image Credit: NASA

Aquarius soil moisture data are coarser than those collected by the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) mission. Still, having multiple missions in orbit that simultaneously measure the wetness of the land in the same band of the microwave spectrum ensures a more continuous record, said Peggy O'Neill, of NASA's Goddard Space Flight Center in Greenbelt, Maryland, a co-investigator of the soil moisture project and deputy project scientist of NASA's upcoming soil moisture mission, SMAP.

Image above: This image of Africa, taken in January 2013, shows the typical rain pattern for the continent during the Southern Hemisphere's summer: a wide band of wet soil (in blue) matching the rain belt has moved south from the equator as summer progresses. Image Credit: NASA Goddard's Science Visualization Studio/T. Schindler.

"One of the things that having Aquarius and SMOS in orbit before SMAP has allowed us to do is to do inter-comparison studies between the sensors," O'Neill said. "By having the three instruments up there at the same time, we will be able to create a long-time series of soil moisture that starts with SMOS and continues with Aquarius and then SMAP. We won't have to worry that the earlier data were taken by SMOS and the later data by SMAP – we'll know they're telling us the same thing. If we hadn't been able to do inter-comparison studies and there had been no overlap between the three instruments, we wouldn’t know how to merge the measurements together."

SMAP, set to launch in November 2014, will advance soil moisture studies with its greater spatial and temporal resolution. The new mission will combine microwave radiometer readings, which are accurate but coarse, with the measurements taken by its onboard radar, which are less precise but have higher spatial resolution than the radiometer data. This approach will provide a footprint of 5.6 miles (9 kilometers), and it will produce worldwide soil moisture maps every three days. Taken together these features of SMAP will provide about 500 times the number of soil moisture measurements per day compared to SMOS or Aquarius.

"Weather and climate models now need information in the 10-kilometer scale," O'Neill said. "SMAP will also allow professionals who now do drought monitoring and flood forecasting at the county level to be able to do it at sub-county levels."

The Aquarius mission and radar were developed at NASA’s Jet Propulsion Laboratory in Pasadena, California, and the radiometer was developed at NASA’s Goddard Space Flight Center. The Aquarius soil moisture product and sea surface salinity measurements are produced by NASA's Goddard Space Flight Center, which manages the mission. Soil moisture data from NASA's Aquarius microwave radiometer are now available at the National Snow and Ice Data Center.

Related links:

For more information about Aquarius Mission, visit: http://aquarius.nasa.gov/

National Snow and Ice Data Center: http://nsidc.org/data/aquarius/index.html

NASA's "Earth Right Now" website: http://www.nasa.gov/earthrightnow/

Images (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA's Earth Science News Team / Maria-José Viñas.

Best regards, Orbiter.ch

NASA Satellites See Neoguri Grow into a Super Typhoon

NASA - EOS TERRA Mission patch.

July 7, 2014

  Neoguri (Northwestern Pacific Ocean)

Image above: The MODIS instrument aboard NASA's Terra satellite captured this visible image of Typhoon Neoguri on July 5 at 01:20 UTC (July 4 at 9:20 p.m. EDT) as it moved through the Northwestern Pacific Ocean. Image Credit: NASA Goddard MODIS Rapid Response Team.

From July 4 to July 7 Tropical Cyclone Neoguri strengthened from a tropical storm into a supertyphoon. NASA's Terra and Aqua satellites passed over the rapidly intensifying storm and provided forecasters with visible, infrared and microwave data on the powerful supertyphoon.

On July 4 at 0900 UTC (5 a.m. EDT) Neoguri had maximum sustained winds near 55 knots (63.2 mph/101.9 kph). It was located near 13.1 north and 141.4 east, about 207 nautical miles (238.2 miles/383.4 km) west of Andersen Air Force Base, Guam. It was moving to the northwest at 13 knots (14.9 mph/24.0 kph). This visible image from the MODIS instrument aboard NASA's Aqua satellite at 03:40 UTC on July 4 showed the bulk of the clouds and showers south and east of a clear eye.

NASA's Terra satellite passed over Neoguri as it became a typhoon on July 5. At 01:20 UTC (July 4 at 9:20 p.m. EDT) the Moderate Resolution Imaging Spectroradiometer known as MODIS that flies aboard Terra captured a visible image of Neoguri as it moved through the Northwestern Pacific Ocean. The MODIS image showed a clear eye, and a large, thick band of thunderstorms in the southern quadrant of the storm wrapping into the center.

NASA's Terra satellite. Image Credit: NASA / GFSC

On July 5 at 0900 UTC (5 a.m. EDT) satellite data helped confirm that Neoguri had become a typhoon in the Northwestern Pacific after it passed Guam. At that time it was centered near 16.0 north and 137.0 east, about 813 nautical miles (935.6 miles/1,506 km) southeast of Kadena Air Base. It was moving west-northwest at 14 knots (16.1 mph/25.9 kph) and had maximum sustained winds near 115 knots (132.3 mph/213.0 kph).

On July 6 Typhoon Neoguri continued to strengthen. Neoguri was located near 18.5 north and 131.4 east at 0900 UTC (5 a.m. EDT) on July 6. That's about 661 nautical miles (760.7 miles/1,224 km) southeast of Kadena Air Base, Okinawa, Japan. It had maximum sustained winds near 120 knots (138.1 mph/222.2 kph) and was moving to the west-northwest at 15 knots (17.2 mph/27.7 kph). The Joint Typhoon Warning Center or JTWC noted that Neoguri was generating very rough and high seas as high as 32 feet (9.7 meters).

Image above: This false-colored infrared image of Supertyphoon Neoguri was taken by the AIRS instrument aboard NASA's Aqua satellite on July 6 at 17:17 UTC (1:17 p.m. EDT). Purple indicates strongest thunderstorms. Credit: Image Credit: NASA JPL, Ed Olsen.

A false-colored infrared image of Supertyphoon Neoguri on July 6 at 17:17 UTC (1:17 p.m. EDT) was made at NASA's Jet Propulsion Laboratory in Pasadena, California using data from the Atmospheric Infrared Sounder (AIRS) instrument. AIRS flies aboard NASA's Aqua satellite. The infrared imagery showed very cold, high, powerful thunderstorms around the center of Neoguri's 40-nautical-mile-wide-eye and in a thick band south of the center.

By July 7 at 1500 UTC (11 a.m. EDT), Neoguri had grown into a supertyphoon with maximum sustained winds near 130 knots (149.6 mph/240.8 kph). The JTWC expects Neoguri to strengthen further. Neoguri was located near 21.6 north latitude and 127.3 east longitude, about 246 nautical miles (283.1 miles/455.6 km) south-southwest of Kadena Air Base, Okinawa, Japan. It was moving to the northwest at 15 knots (17.2 mph/27.7 kph). As Neoguri strengthened, the ocean has become more turbulent, and JTWC estimates maximum significant wave heights near 40 feet (12.1 meters).  

Tropical storm-force winds extend 210 nautical miles (241.7 miles/388.9 km) from the center, and hurricane-force winds extend up to 60 nautical miles (69.0 miles/111.1 km) from the center.

For a graphic of watches in warnings in effect in Japan, visit the Japan Meteorological Agency's page: http://www.jma.go.jp/en/warn/.

Neoguri is moving northwest and continuing to strengthen. The JTWC expects Neoguri to turn to the north late on July 7 (EDT) and pass Kadena Air Base. A landfall in Kyushu is expected by July 9. The JTWC noted in a July 7 discussion: by July 9, cooling sea surface temperatures, increasing vertical wind shear ahead of the mid-latitude westerlies (winds), and landfall into Kyushu, Japan, will slowly erode the system.

For more information about EOS Terra mission, visit: http://science.nasa.gov/missions/terra/

Images (mentioned), Text, Credits: NASA's Goddard Space Flight Center / Rob Gutro.

Greetings, Orbiter.ch

Newfound Frozen World Orbits in Binary Star System

NASA patch.

July 4, 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.

Image above: This artist's rendering shows a newly discovered planet (far right) orbiting one star (right) of a binary star system. Image Credit: Cheongho Han, Chungbuk National University, Rep. of Korea.

“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://orbiterchspacenews.blogspot.ch/2011/09/nasas-kepler-discovery-confirms-first.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."

Wide-Field Infrared Survey Telescope (WFIRST-AFTA). Image Credit: NASA

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, website: http://wfirst.gsfc.nasa.gov/

WFIRST: Uncovering the Mysteries of the Universe.

Video above: The Wide-Field Infrared Survey Telescope (WFIRST) is an upcoming space telescope designed to perform wide-field imaging and spectroscopy of the infrared sky. One of WFIRST's objectives will be looking for clues about dark energy--the mysterious force that is accelerating the expansion of the universe. Another objective of the mission will be finding and studying exoplanets. Video Credit: NASA Goddard Space Flight Center.

WFIRST uses the same 2.4 meter telescope size as Hubble, but with 18 cutting-edge fourth-generation image sensors compared to Hubble's single first-generation sensor. As a result, each WFIRST image will cover over 200 times as much as a Hubble Wide Field Camera 3/IR image and be 300 megapixels in size. Hubble images reveal thousands of galaxies; a single WFIRST image will uncover millions.

To help uncover the mystery of dark energy, WFIRST will make incredibly precise measurements of the universe. These measurements, like the distance and position of galaxies, can be compared to other measurements—such as the cosmic microwave background from the WMAP mission—to determine how dark energy has changed over time. WFIRST can also measure the slight distortions in light from distant galaxies as it passes more nearby mass concentrations. These data will build a three dimensional picture of how mass is distributed throughout the universe, and provide independent confirmation of its structure.

Because WFIRST has such a large and sensitive field of view, it can find thousands of new exoplanets through a process called microlensing. When one star in the sky appears to pass nearly in front of another, the light rays of the background source star become bent due to the gravitational "attraction" of the foreground star. This "lens" star is then a virtual magnifying glass, amplifying the brightness of the background source star. If the lens star harbors a planetary system, then those planets can also act as lenses, each one producing a short deviation in the brightness of the source. For closer planets, WFIRST will open a new era of direct observation. Currently only a handful of planets are observable in light reflected off of them, and they are all large planets close to their stars. WFIRST will be able to resolve planets as small as Neptune, and as far from their stars as Saturn is from the sun. This is possible thanks to newly developed coronagraphs, which block the bright light from the star to make the planet more visible.

Read the full news release from Ohio State at: http://news.osu.edu/news/2014/07/03/planet-discovery-expands-search-for-earthlike-planets/

Images (mentioned), Video (mentioned), Text, Credits: NASA / JPL / Whitney Clavin.

Greetings, Orbiter.ch

Rockot rocket orbited block spacecraft Messenger-M

ROSCOSMOS logo.

07/03/2014

Launch of Rockot rocket at Plesetsk cosmodrome

On July 3 at 16 hours 43 minutes Moscow time on state testing cosmodrome Ministry of Defence of the Russian Federation (Plesetsk cosmodrome) started launch (ILV) Rockot with the upper stage Breeze-KM and three spacecraft (SC) Messenger-M multifunctional system of personal satellite communication and data transmission (MSPSS).

Launch executed by combat crew specialists from the Ministry of Defense of the Russian Federation and representatives of the space industry.

Launch of three Gonets-M comsats on a Rokot from Plesetsk

In the estimated time block spacecraft Messenger-M (production - JSC Information Satellite Systems them. Academician Reshetnev) displayed on the target orbit.

Booster light class "Roar" and the upper stage Breeze-KM created at the State Research and Production Space Center. Khrunichev.

Rockot rocket description

Multifunction personal satellite communication system and data from the spacecraft in low orbits Messenger-D1M created under the Federal Space Program commissioned by Roscosmos and is able to solve the problem of providing personal communications and data of various types, including coordinate-time satellite data coordination system GLONASS.

Gonets-M communication satellite

Services, built on the basis of the Messenger solve the problem of monitoring the various infrastructures transmit navigation and timing data obtained by the GLONASS system, with moving objects in different dispatching centers and monitoring, as well as personal communications in remote areas.

ROSCOSMOS Press Release: http://www.federalspace.ru/20747/

Images, Video, Text, Credits: Roscosmos press service / ROSCOSMOS / Translation: Orbiter.ch Aerospace.

Best regards, Orbiter.ch

STEREO Solar Conjunction

NASA - STEREO Mission logo.

July 3, 2014

Since February 2011, the two spacecraft of NASA's the Solar Terrestrial Relations Observatory or STEREO mission have been providing scientists with unprecedented views of the far side of the sun.

The spacecraft travel at different speeds. This means that over time, the satellites become increasingly out of sync, appearing from Earth's perspective to drift farther apart, able to observe first the sides and eventually the far side of the sun. Now they are nearing each other once again, this time on the other side of the sun. During this period when the sun blocks Earth's view -- a geometrical position known in astronomy as a superior conjunction -- radio receivers on Earth will not be able to distinguish STEREO's signal from the sun's radiation. Communication with the spacecraft will cease and the satellites will both go into safe mode without collecting data for a time.

STEREO Solar Conjunction

This will happen for STEREO-Ahead from March 24 to July 7, 2015. STEREO-Behind will be in superior conjunction from Jan. 22 to March 23, 2015. At least one spacecraft, therefore, will always be collecting data. Before this occurs, the heating from the sun will also begin to affect - though not shut down -- data collection. From wherever they are in space, the STEREO spacecraft aim their antenna toward Earth to send down data. This position puts the antenna fairly close to pointing at the sun, exposing the instruments to more heat than it can safely bear. The antenna can be adjusted to point in different directions, but the signal coming to Earth will be much fainter and won't allow for as much data to be downloaded.

This antenna adjustment will begin on Aug. 20, 2014, for the STEREO-Ahead spacecraft and on Dec. 1, 2014, for STEREO-Behind. During this phase, STEREO instruments will continue to run 24 hours a day, but they will gather lower-resolution data than usual. Some of this data will be downloaded whenever STEREO can link up with an Earth receiver. The rest of the data will be stored on board to be downloaded when the spacecraft reach a more auspicious geometrical position in early 2016. To test for this off-pointing from the sun, STEREO-Ahead will undergo tests and not be collecting data from July 6-12, 2014. The same tests will be performed on STEREO-Behind from Sept. 29 - Oct. 6, 2014.

STEREO spacecraft

Throughout this entire phase until 2016, at least one STEREO spacecraft will be capturing data at any one time, so scientists will have an uninterrupted record of events on the sun to coordinate with the observations of solar telescopes on the Earth side. Real time monitoring of the sun, its flares and coronal mass ejections - information used by the US National Oceanic and Atmospheric Administration to help forecast space weather -- will also continue via a fleet of NASA spacecraft closer to Earth.

This video is public domain and can be downloaded at: http://svs.gsfc.nasa.gov/goto?11602

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For more information about STEREO Mission, visit: http://www.nasa.gov/mission_pages/stereo/main/ and http://stereo.gsfc.nasa.gov/

Image, Video, Text, Credit: NASA's Goddard Space Center.

Greetings, Orbiter.ch

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

NASA - OCO-2 Mission logo.

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.

Image above: 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.

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.

Image above: An artist's rendering of the atmospheric column OCO-2 will see and the sunlight it will examine for evidence of carbon dioxide. Carbon dioxide molecules, with two oxygen atoms and a carbon atom, are represented in red and black. Image Credit: NASA/JPL-Caltech.

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 and 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

Images (mentioned), Credits: NASA / JPL / Alan Buis, written by Rosalie Murphy, JPL Earth Science and Technology Directorate.

Cheers, Orbiter.ch

Comet Pan-STARRS Marches Across the Sky

NASA - NEOWISE Mission logo.

July 3, 2014

NEOWISE Spies Comet Pan-STARRS Against Galaxy Backdrop

Video above: NASA's NEOWISE mission captured a series of infrared images of comet C/2012 K1 -- also referred to as comet Pan-STARRS -- as it swept across our skies in May 2014. Image Credit: NASA/JPL-Caltech.

NASA's NEOWISE mission captured a series of pictures of comet C/2012 K1 -- also known as comet Pan-STARRS -- as it swept across our skies in May 2014.

The comet is named after the astronomical survey project called the Panoramic Survey Telescope and Rapid Response System in Hawaii, which discovered the icy visitor in May 2012.

Comet Pan-STARRS hails from the outer fringes of our solar system, from a vast and distant reservoir of comets called the Oort cloud.

The comet is relatively close to us -- it was only about 143 million miles (230 million kilometers) from Earth when this picture was taken. It is seen passing a much more distant spiral galaxy, called NGC 3726, which is about 55 million light-years from Earth, or 2 trillion times farther away than the comet.

Two tails can be seen lagging behind the head of the comet. The bigger tail is easy to see and is comprised of gas and smaller particles. A fainter, more southern tail, which is hard to spot in this image, may be comprised of larger, more dispersed grains of dust.

Image above: NASA's NEOWISE mission captured this series of pictures of comet C/2012 K1 -- also known as comet Pan-STARRS -- as it swept across our skies on May 20, 2014. Image Credit: NASA/JPL-Caltech.

Comet Pan-STARRS is on its way around the sun, with its closest approach to the sun occurring in late August. It was visible to viewers in the northern hemisphere through most of June. In the fall, after the comet swings back around the sun, it may be visible to southern hemisphere viewers using small telescopes.

The image was made from data collected by the two infrared channels on board the NEOWISE spacecraft, with the longer-wavelength channel (centered at 4.5 microns) mapped to red and the shorter-wavelength channel (3.4 microns) mapped to cyan. The comet appears brighter in the longer wavelength band, suggesting that the comet may be producing significant quantities of carbon monoxide or carbon dioxide.

Originally called the Wide-field Infrared Survey Explorer (WISE), the NEOWISE spacecraft was put into hibernation in 2011 after its primary mission was completed. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE is also characterizing previously known asteroids and comets to better understand their sizes and compositions.

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the NEOWISE mission for NASA's Near-Earth Object Observation Program of its Planetary Science Division in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colorado, built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information on NEOWISE is online at: http://www.nasa.gov/wise and http://www.jpl.nasa.gov/wise/

Image (mentioned), Video (mentioned), Text, Credits: NASA / JPL / Whitney Clavin.

Greetings, Orbiter.ch