NASA’s 3-D Study of Comets Reveals Chemical Factory at Work

NASA logo.

August 11, 2014

A NASA-led team of scientists has created detailed 3-D maps of the atmospheres surrounding comets, identifying several gases and mapping their spread at the highest resolution ever achieved.

“We achieved truly first-of-a-kind mapping of important molecules that help us understand the nature of comets,” said Martin Cordiner, a researcher working in the Goddard Center for Astrobiology at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Cordiner led the international team of researchers.

Almost unheard of for comet studies, the 3-D perspective provides deeper insight into which materials are shed from the nucleus of the comet and which are produced within the atmosphere, or coma. This helped the team nail down the sources of two key organic, or carbon-containing, molecules.

HCN - Inner coma of C/2012 F6 (Lemmon)

Video above: This rotating 3-D map shows how HCN molecules (made of hydrogen, carbon and nitrogen) are released from the nucleus of comet Lemmon and then spread evenly throughout the atmosphere, or coma. Similar maps revealed that HNC and formaldehyde are produced in the coma, rather than the comet's nucleus. Image Credit: Brian Kent/NRAO/AUI/NSF.

The observations were conducted in 2013 on comets Lemmon and ISON using the Atacama Large Millimeter/submillimeter Array, or ALMA, a network of high-precision antennas in Chile. These comets are the first to be studied with ALMA.

The ALMA observatory. Image Credit: ESO

The ALMA observations combine a high-resolution 2-D image of a comet’s gases with a detailed spectrum at each point. From these spectra, researchers can identify the molecules present at every point and determine their velocities (speed plus direction) along the line-of-sight; this information provides the third dimension – the depth of the coma.

“So, not only does ALMA let us identify individual molecular species in the coma, it also gives us the ability to map their locations with great sensitivity,” said Anthony Remijan, a scientist with the National Radio Astronomy Observatory, one of the organizations that operates ALMA, and a co-author of the study.

The researchers reported results for three molecular species, focusing primarily on two whose sources have been difficult to discern (except in comet Halley). The 3-D maps indicated whether each molecule was flowing outward evenly in all directions or coming off in jets or in clumps.

U.S. National Radio Astronomy Observatory (NRAO). Image Credit: NRAO

In each comet, the team found that two species – formaldehyde and HNC (made of one hydrogen, one nitrogen and one carbon) – were produced in the coma. For formaldehyde, this confirmed what researchers already suspected, but the new maps contained enough detail to resolve clumps of the material moving into different regions of the coma day-by-day and even hour-by-hour.

For HNC, the maps settled a long-standing question about the material’s source. Initially, HNC was thought to be pristine interstellar material coming from the nucleus of a comet, whereas later work suggested other possible sources. The new study provided the first proof that HNC is produced during the breakdown of large molecules or organic dust in the coma.

“Understanding organic dust is important, because such materials are more resistant to destruction during atmospheric entry, and some could have been delivered intact to early Earth, thereby fueling the emergence of life,” said Michael Mumma, Director of the Goddard Center for Astrobiology, and a co-author on the study. “These observations open a new window on this poorly known component of cometary organics.”

National Astronomical Observatory of Japan. Image Credit: NAOJ

The observations, published today by the Astrophysical Journal Letters, also were significant because modest comets like Lemmon and ISON contain relatively low concentrations of crucial molecules, making them difficult to probe in depth with Earth-based telescopes. The few comprehensive studies of this kind so far have been conducted on bright, blockbuster comets, such as Hale-Bopp. The present results extend them to comets of only moderate brightness.

This research was funded by the NASA Astrobiology Institute through the Goddard Center for Astrobiology and by NASA’s Planetary Atmospheres and Planetary Astronomy programs. ALMA is an international astronomy facility. Its construction and operations are led on behalf of Europe by the European Southern Observatory, on behalf of North America by the U.S. National Radio Astronomy Observatory (NRAO) and on behalf of East Asia by the National Astronomical Observatory of Japan.

For more information about NASA and agency programs, visit: http://www.nasa.gov

Images (mentioned), Video (mentioned), Text, Credits: NASA’s Goddard Space Flight Center / Elizabeth Zubritsky / NASA’s Goddard Space Flight Center / Nancy Neal-Jones.

Best regards, Orbiter.ch

Saturn's moon Rhea, Epimetheus transiting

NASA / ESA - Cassini International logo.

Aug. 11, 2014

Saturn has a great many more moons than our planet – a whopping 62. A single moon, Titan, accounts for an overwhelming 96% of all the material orbit the planet, with a group of six other smaller moons dominating the rest. The other 55 small satellites whizzing around Saturn make up the tiny remainder along with the gas giant’s famous rings.

One of the subjects of this Cassini image, Rhea, belongs to that group of six. Set against a backdrop showing Saturn and its intricate system of icy rings, Rhea dominates the scene and dwarfs its tiny companion, one of the 55 small satellites known as Epimetheus.

Although they appear to be close to one another, this is a trick of perspective – this view was obtained when Cassini was some 1.2 million km from Rhea, and 1.6 million km from Epimetheus, meaning the moons themselves had a hefty separation of 400 000 km.

However, even if they were nearer to each other, Rhea would still loom large over Epimetheus: at 1528 km across and just under half the size of our own Moon, Rhea is well over 10 times the size of Epimetheus, which is a modest 113 km across.

As is traditional for the earliest discovered moons of Saturn, both are named after figures from Greek mythology: the Titan Rhea (“mother of the gods”) and Prometheus’ brother Epimetheus (“after thinker” or “hindsight”).

This image was taken by Cassini’s narrow-angle camera on 24 March 2010, and processed by amateur astronomer Gordan Ugarković. A monochrome version was previously released by NASA as PIA12638: Big and Small Before Rings.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate in Washington.

Related link:

PIA12638: Big and Small Before Rings: http://photojournal.jpl.nasa.gov/catalog/PIA12638

For more information about Cassini, visit: http://www.nasa.gov/cassini and
http://saturn.jpl.nasa.gov and http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image data Credit: NASA/JPL-Caltech/Space Science Institute; Processed image copyright: G. Ugarković/Text: ESA.

Greetings, Orbiter.ch

Flight tests Meteor-M №2 continue

ROSCOSMOS patch.

09/08/2014

Shooting of MSU-MR Meteor-M №2, Black Sea / 30.07.2014

Work on the flight test program hydrometeorological spacecraft (SC) Meteor-M №2, running July 8, 2014 from the Baikonur Cosmodrome, continue.

Shooting of  KMSS 100 Meteor-M № 2 of Greece / 29.07.2014

To date, completed the inclusion of key devices of the target spacecraft equipment. Tests have been conducted target equipment in accordance with the partial flight test program. According to preliminary estimates of experts, information obtained in the whole of Central Asia meets the specified requirements.

Western Hemisphere SM-A radio channel 18,7GGts GP; 31.07.2014

 Eastern Hemisphere SM-A radio channel 36,5GGts GP; 31.07.2014

Since the launch of the spacecraft performed a check of all the systems on board the spacecraft. Parameters characterizing the state of the spacecraft are within normal limits.

MTVZA-GYa Meteor-M №2 31.07.2014. Mercator projection channel 36,5GGts VI; CM-radio link

ROSCOSMOS Press Release: http://www.federalspace.ru/20831/

Images, Text, Credits: The press service of the Russian Space Agency and JSC "Corporation VNIIEM" / ROSCOSMOS / Translation: Orbiter.ch Aerospace.

Greetings, Orbiter.ch

NASA Watches Storms in the Pacific

NASA - TRMM Mission patch / NASA/NOAA - GOES-West Mission patch.

August 8, 2014

Iselle (Eastern Pacific Ocean); Tropical Storm Iselle Hits Hawaii

Image above: The TRMM satellite had an excellent view of tropical storm Iselle as it neared the Hawaiian islands on August 8, 2014. Image Credit: SSAI/NASA, Hal Pierce.

Hurricane Iselle weakened to a tropical storm while approaching the island of Hawaii on Thursday August 7, 2014. As a tropical storm Iselle contained some heavy rain showers and strong winds when it hit the big island.

Iselle later dropped some heavy rain over Maui and scattered showers extended to Kauai and Oahu.

Image above: NOAA's GOES-West satellite. Image Credit: NASA/NOAA.

The TRMM satellite had an excellent view of tropical storm Iselle as it neared the Hawaiian islands on August 8, 2014 at 0152 UTC ( August 7 at 3:52 PM HST). A rainfall analysis from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) instruments is shown overlaid on a 0200 UTC GOES-WEST image. TRMM's TMI collected data showing that rain was falling at a rate of over 39 mm (1.5 inches) per hour near Iselle's center.

After crossing the island of Hawaii, Iselle is predicted to continue weakening as its center of circulation passes to the south of the other Hawaiian Islands.

TRMM and GOES Satellites See Hurricanes Iselle and Julio Menacing Hawaii

The Tropical Rainfall Measuring Mission or TRMM satellite and NOAA's GOES-West satellite saw both weakening Hurricane Iselle and category two hurricane Julio at the same time on August 7 from its orbit in space because both storms are so close to each other in the Central Pacific Ocean.

Image above: Visualization of the TRMM satellite in space over a hurricane. Image Credit: NASA.

Both Iselle and Julio were moving toward the Hawaiian Islands on August 7, 2014 at 0922 UTC (5:22 a.m. EDT) when TRMM passed overhead. TRMM's Microwave Imager (TMI) instrument collected data as it passed overhead. Microwave brightness temperatures at 85.5 GHZ and at 37.0 GHZ were combined in the red, green and blue components to construct the image. Brightness temperature is a measurement of the radiance of the microwave radiation traveling upward from the top of the atmosphere to the satellite. The brighter the temperature, the more energy is being generated.

Image above: This GOES-West satellite image from August 7 at 1800 UTC (2 p.m. EDT) shows Hurricane Iselle approaching Hawaii and Hurricane Julio behind to the east. Image Credit: NASA/NOAA GOES Project.

NOAA's GOES-West satellite captured an image of both storms on August 7 at 1800 UTC (2 p.m. EDT) as Iselle was approaching Hawaii and Hurricane Julio followed behind to the east. In the image, Julio appeared to have a better, more organized circulation.

An Air Force reconnaissance aircraft data shows that Iselle is no longer a hurricane and is on a weakening trend.  The eyewall was no longer visible on aircraft radar.  Flight level winds in the storm were near 60 knots and surface winds near 57 knots.  Iselle's forward motion has slowed as a weakness developed within the storm.  A mid and upper level low is forecast to develop within the weakness over the next couple of days that will cause the system to weaken to a shallow low.

Image above: The TRMM satellite saw both weakening Hurricane Iselle and category two Hurricane Julio in the same orbit as they were moving toward the Hawaiian islands on August 7, 2014. Image Credit: SSAI/NASA, Hal Pierce.

Iselle is not expected to survive after it makes landfall on the Big Island due to the interaction with the terrain and the strong shear along its track.  However, if it is able to survive landfall, a new ridge may develop north of the forecast track and it may strengthen again to hurricane strength prior to reaching the international dateline.

Image above: On August 9 at 23:15 UTC, the MODIS instrument aboard NASA's Aqua satellite took this visible image of Hurricane Iselle in the Eastern Pacific Ocean. Image Credit: NASA Goddard MODIS Rapid Response Team.

At 3:00 am HST, 1300 UTC, the center of tropical storm Iselle was located near latitude 19.2 north, longitude 155.4 west. Iselle is moving toward the west near 10 mph, 17 km/h, and this motion is expected to continue through Saturday, with an increase in forward speed.  Tropical storm force winds extend outward up to 175 miles, 280 km from the center.

Satellite Movie Shows Hurricane Iselle and Julio Moving Toward Hawaii 

Video above: This animation of NOAA's GOES-East satellite imagery from August 2 through 7 shows the movement of Hurricanes Iselle (left) and Julio (right) toward the Hawaiian Islands. Video Credits: NASA/NOAA GOES Project.

For updated forecasts on Iselle, please visit NOAA's Central Pacific Hurricane Center website at: http://www.prh.noaa.gov/cphc/tcpages/ISELLE.php. For updated forecasts on Hurricane Julio, please visit NOAA's National Hurricane Center website: http://www.nhc.noaa.gov.

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center / Hal Pierce / Lynn Jenner.

Best regards, Orbiter.ch

Sun sets for a NASA solar monitoring spacecraft

NASA - AcrimSat Mission patch.

August 8, 2014

After 14 years of monitoring Earth's main energy source, radiation from the sun, NASA’s Active Cavity Radiometer Irradiance Monitor satellite has lost contact with its ground operations team at NASA's Jet Propulsion Laboratory, Pasadena, California, and its mission has been declared completed.

AcrimSat's ACRIM 3 instrument was the third in a series of satellite experiments that have contributed to a critical data set for understanding Earth's climate: the 36-year, continuous satellite record of variations in total solar radiation reaching Earth, or total solar irradiance. The three ACRIM instruments have supplied state-of-the-art data during more than 90 percent of that time. Three other satellite instruments launched in 1995, 2003 and 2013 continue to monitor total solar irradiance.

Launched on Dec. 21, 1999, for a planned five-year mission, AcrimSat went silent on Dec. 14, 2013. Attempts since then to reestablish contact have been unsuccessful. The venerable satellite most likely suffered an expected, age-related battery failure.

Image above: Artist's rendering of the AcrimSat spacecraft. Image Credit: NASA.

The sun puts out a fairly stable amount of energy compared with many other stars. "That's where the term 'solar constant' comes from," said AcrimSat project manager Sandy Kwan of JPL, referring to a standard unit of measurement in astronomy. Over the sun's 11-year cycle, the average variation in visible light is about one-tenth of one percent -- a change so small that scientists only discovered it when they were able to observe the sun from satellites above our light-scattering atmosphere. Kwan pointed out that AcrimSat's grandfather, the ACRIM 1 instrument on the Solar Maximum Mission satellite launched in 1980, was the first instrument to show clearly that solar irradiance does vary.

Although the percentage of change is minuscule, the energy it represents can have important effects on Earth. Scientists believe that sustained changes of as little as 0.25 percent in total solar irradiance over periods of decades to centuries caused significant climate change in Earth's distant past. Today, as greenhouse gases accumulate in the atmosphere, it's critical to understand the relative contributions of variations in solar irradiance and human-produced greenhouse gases to changes in Earth’s climate. To gain that knowledge, a long, continuous series of solar observations is an essential tool.

"The data record from the ACRIM series remains valuable for studying solar variability," said Greg Kopp, a senior research scientist at the University of Colorado's Laboratory of Astrophysics and Space Physics in Boulder. "This more than three-decade-long data series exceeds the duration of any other irradiance instruments."

Richard Willson, ACRIM principal investigator, has used the ACRIM data set to study cycles in the sun's variations. With co-investigator Nicola Scafetta of Duke University, Durham, North Carolina, Willson has been able to attribute some regular cycles of variation in irradiance to the alignment of planets and their gravitational tug on the sun. "The sun, Earth and Jupiter are aligned in their orbits every 1.09 years, and we see a bump in solar irradiance every year at that time," Willson explained. "That's just one of many cycles we have found. People have guessed at these effects for 150 years, but finding these frequencies in ACRIM data made it possible to pin down the effects for the first time."

Image above: Dark sunspots and bright areas around them called faculae, visible in this 2001 solar image, cause most of the variation in total solar irradiance. Image Credit: NASA/GSFC/SVS.

Willson noted that the cycles have been connected with past changes in climate through analyses of air trapped for centuries in glacial ice. "Our measurements have contributed significantly to understanding the sun's effect on climate on time scales up to half a million years."

AcrimSat was built at a cost of $26 million, equivalent to about $45 million today. Kwan noted that the ACRIM 3 instrument was still working perfectly when the satellite lost contact and that AcrimSat's batteries had far exceeded their shelf life.

The spacecraft, built by Orbital Sciences Corporation in Dulles, Virginia, remains safely in orbit about 435 miles (700 kilometers) above Earth and is expected to stay aloft for another 64 years.

For more information on AcrimSat, please visit: http://acrim.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.

To learn more about NASA's Earth science activities in 2014, visit: http://www.nasa.gov/earthrightnow

Images (mentioned), Text, Credit: NASA.

Greetings, Orbiter.ch

Cassini Prepares For Its Biggest Remaining Burn

NASA / ESA - Cassini Mission to Saturn patch.

August 8, 2014

NASA's Cassini spacecraft will execute the largest planned maneuver of the spacecraft's remaining mission on Saturday, Aug. 9. The maneuver will target Cassini toward an Aug. 21 encounter with Saturn's largest moon, Titan.

The main engine firing will last about a minute and will provide a change in velocity of 41 feet per second (12.5 meters per second). This is the largest maneuver by Cassini in five years. No other remaining maneuver comes close, in the amount of propellant it will consume and the amount by which it will change the spacecraft's velocity. By contrast, the smallest maneuvers Cassini routinely executes are about 0.4 inches (10 millimeters) per second.

Image above: Artist's concept of the Cassini spacecraft during Saturn orbit insertion. Cassini mission controllers are preparing for the biggest remaining burn planned for the mission, which is slated for Aug. 9. Image Credit: NASA/JPL-Caltech.

The large size of the Aug. 9 burn is needed to begin the process of "cranking down" Cassini's orbit, so that the spacecraft circles Saturn nearer to the plane of the rings and moons. Previously, with each Titan flyby, mission controllers adjusted the spacecraft's orbit to be increasingly inclined, carrying Cassini high above Saturn's polar regions. The upcoming maneuver starts reversing that trend, making the orbit increasingly close to the equator.

Although Cassini has occasionally performed similar large propulsive maneuvers during its decade in the Saturn system, Titan itself has proven to be the workhorse for steering Cassini around Saturn. It is not uncommon for the spacecraft to receive a gravitational assist, or boost, from Titan that rivals or exceeds the 96-minute engine burn Cassini performed in 2004 to insert itself into Saturn orbit.

The Cassini mission recently celebrated a decade studying Saturn, its rings, moons and magnetosphere.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, California, manages the mission for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology.

For more information about Cassini, visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov and http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image (mentioned),  Text, Credits: NASA / JPL / Preston Dyches.

Cheers, Orbiter.ch

Ride Shotgun With NASA Saucer As It Flies to Near Space

NASA patch.

August 8, 2014

NASA's Low-Density Supersonic Decelerator (LDSD) project successfully flew a rocket-powered, saucer-shaped test vehicle into near-space in late June from the U.S. Navy's Pacific Missile Range Facility on Kauai, Hawaii. The goal of this experimental flight test, the first of three planned for the project, was to determine if the balloon-launched, rocket-powered, saucer-shaped, design could reach the altitudes and airspeeds needed to test two new breakthrough technologies destined for future Mars missions.

LDSD: Supersonic Test Flight

Video above: Rockets fire in this video clip captured by the test vehicle for NASA's Low-Density Supersonic Decelerator project. The test occurred above the Pacific Ocean, near Hawaii. Video Credit: NASA/JPL-Caltech.

Carried as payload during the shakeout flight were two cutting-edge technologies scheduled to be tested next year aboard this same type of test vehicle. The Supersonic Inflatable Aerodynamic Decelerator (SIAD) is a large, doughnut-shaped air brake that deployed during the flight, helping slow the vehicle from 3.8 to 2 times the speed of sound. The second, the Supersonic Disksail Parachute, is the largest supersonic parachute ever flown. It has more than double the area of the parachute which was used for the Mars Science Laboratory (MSL) mission that carried the Curiosity rover to the surface of Mars.

Image above: Moments into its powered flight, the LDSD test vehicle captured this image of the balloon which carried it to high altitudes. The image was taken by one of the saucer-shaped test vehicle's high-resolution cameras. Image Credit: NASA/JPL-Caltech.

"A good test is one where there are no surprises but a great test is one where you are able to learn new things, and that is certainly what we have in this case." said Ian Clark, principal investigator for LDSD at NASA's Jet Propulsion Laboratory in Pasadena, California. "Our test vehicle performed as advertised. The SIAD and ballute, which extracted the parachute, also performed beyond expectations. We also got significant insight into the fundamental physics of parachute inflation. We are literally re-writing the books on high-speed parachute operations, and we are doing it a year ahead of schedule."

Image above: The test vehicle for NASA's Low-Density Supersonic Decelerator is seen here before and after the balloon that helped carry it to near-space was deflated. Image Credit: NASA/JPL-Caltech.

Hitching a ride aboard the 7,000-pound saucer were several high-definition video cameras. The arresting imagery is providing the engineers and scientists on the LDSD project with never before seen insights into the dynamics involved with flying such a vehicle at high altitudes and Mach numbers.

Image above: Divers retrieve the test vehicle for NASA's Low-Density Supersonic Decelerator off the coast of the U.S. Navy's Pacific Missile Range Facility in Kauai, Hawaii. Image Credit: NASA/JPL-Caltech.

"As far as I am concerned, whenever you get to ride shotgun on a rocket-powered flying saucer, it is a good day," said Clark.  "We hope the video will show everyone how beautiful and awesome the test was, and to just to give folks an insight into what experimental flight test is all about."

Low-Density Supersonic Decelerator (LDSD) flight profile. Image Credit: NASA/JPL-Caltech

The high-resolution images and video clips taken during the LDSD test flight are available at: http://go.usa.gov/N5zm

The LDSD cross-cutting demonstration mission tested breakthrough technologies that will enable large payloads to be safely landed on the surface of Mars and allow access to more of the planet's surface by enabling landings at higher altitude sites.

Image above: Moments into its powered flight, the LDSD test vehicle captured this image of the balloon which carried it to high altitudes. The image was taken by one of the saucer-shaped test vehicle's high-resolution cameras. Image Credit: NASA/JPL-Caltech.

NASA's Space Technology Mission Directorate funds the LDSD mission, a cooperative effort led by NASA's Jet Propulsion Laboratory in Pasadena, California. NASA's Technology Demonstration Mission program manages LDSD at NASA's Marshall Space Flight Center in Huntsville, Alabama. NASA's Wallops Flight Facility in Wallops Island, Virginia, coordinated support with the Pacific Missile Range Facility, provided the core electrical systems for the test vehicle, and coordinated the balloon and recovery services for the LDSD test.

For more information about the LDSD space technology demonstration mission: http://go.usa.gov/N5zm

Images (mentioned), Video (mentioned), Text, Credits: NASA / David Steitz / JPL / DC Agle.

Greetings, Orbiter.ch