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

Galileo: it’s all about the time

ESA - Galileo Mission logo.

3 July 2014

Europe’s Galileo satellite navigation system – the combination of satellites in space and stations on the ground – forms a planetary scale timepiece. Current testing shows it keeping very good time indeed – around 10 billionths of a second on average.

To put that in perspective, light waves cover a distance equivalent to more than seven times around planet Earth in one second.

Galileo timing

So why does Galileo need to deliver such precise timing, down to this billionth-of-a-second scale?

Because light – and all other electromagnetic waves, including radio – travels at a fixed speed, just under 30 cm per nanosecond ( a billionth of a second), the time it takes for Galileo signals to reach a user receiver on the ground can be used to yield distance measurements. All the receiver has to do is multiply the travel time by the speed of light.

A minimum of four satellites need to be visible: one each to fix latitude, longitude and altitude, with another to ensure synchronised timings.

So such precise timing becomes essential for accurate positioning. Galileo’s initial four-satellite ‘In Orbit Validation’ testing demonstrates a horizontal accuracy of up to 3 m, 95% of the time, set to improve as more satellites join the system later this year.

How satnav works

In addition, the Galileo System Time (GST) made available through satellite signals is set to become an important utility in its own right, essential to synchronise worldwide banking, power and data networks and a boon for scientific teams.

The challenge has been to maintain GST in a stable manner. Determining GST would, of course, be impossible without the latest high-performance atomic clocks, which use an atom’s switching between tightly-defined energy states for their ‘ticks’.

Ground-based atomic clocks

Because all atoms of a given element and isotope are identical they produce precisely the same high-frequency microwave response when transitioning between states, typically on the order of billions of times per second.

GST is determined using a set of active hydrogen maser atomic clocks at Galileo’s Precise Timing Facility, at Fucino in Italy. The averaged output of these cupboard-sized clocks establish the reference time for the entire Galileo system.

Galileo satellites in space

The satellites themselves house smaller, less accurate rubidium and passive hydrogen maser atomic clocks, the latter being about the size of office fridges. These two designs keep an accuracy of three seconds in one million years and one second in three million years, respectively, though this is not enough by itself to maintain the ultrahigh precision needed.

Corrections are therefore transmitted from the ground on a regular basis, at least once every 100 minutes once the system becomes fully operational, to keep these satellite clocks fully in line with GST.

In addition, while GST itself is determined on a fully independent basis, it is also required to be kept in strict agreement with the international reference time, Universal Time Coordinated or UTC.

Galileo time compared to UTC

This is achieved by continuously comparing GST with the national real time approximations of UTC carried out by  France, Germany, Italy, Spain and Sweden.

The current ‘offset’ between GST and the approximation of UTC (the final measurement of UTC is so precise it is actually calculated weeks afterwards) is determined by Galileo’s Time Validation Facility (the precursor of the Galileo Time Service Provider), which is currently operated by the company GMV in Madrid, Spain.

This process means UTC time measurements can also be made available to users to within an designed accuracy of 26 nanoseconds, although in practice Galileo has been able to do better than this – down to about 5–10 nanoseconds.

Galileo's UTC compared to 'actual'' UTC

Finally, GST also needs to be kept in synch with time system underpinning the US GPS system, known as GPS Time.

To enable user receivers to employ both Galileo and GPS in a seamless manner, the current offset between the two reference times needs to be determined and passed to users through the navigation signal, to an accuracy of 5 nanoseconds or less.

It is officially known as the GPS to Galileo time offset, GGTO. Without it, around 50 nanoseconds’ worth of difference between the two system’s reference times could put users up to 15 m out of place.

Working closely with the US Naval Observatory, which oversees GPS Time, Galileo’s Precise Timing Facility calculates GGTO continuously, the results being distributed through Galileo’s navigation message.

Galileo works, and works well

The current quartet of satellites make Galileo time measurements from at least one satellite possible around two thirds of the time to users.

The launch of two more Galileo satellites, set for this August, will lead to worldwide Galileo timing capability for users at almost all times.

Related links:

Galileo and GPS ‘synchronise watches’: new time offset helps working together: http://www.esa.int/Our_Activities/Navigation/Galileo_and_GPS_synchronise_watches_new_time_offset_helps_working_together

Galileo starts to tell UTC, the world’s time: http://www.esa.int/Our_Activities/Navigation/Galileo_starts_to_tell_UTC_the_world_s_time

Galileo IOV phase information sheet: http://esamultimedia.esa.int/docs/Navigation/galileo_IOV_flyer_final.pdf

Images, Text, Credits: ESA / Anneke Le Floc'h / P. Carril / Airbus Defence & Space.

Best regards, Orbiter.ch

NASA Satellite Spots Heavy Rain Around Arthur's Center

NASA - Tropical Rainfall Measuring Mission (TRMM) logo.

July 2, 2014

NASA's TRMM Satellite Spots Heavy Rainfall Around Tropical Storm Arthur's Center

Image above: One of the Expedition 40 crew members aboard the Earth-orbiting International Space Station, some 227 nautical miles above Earth, photographed this image of Tropical Storm Arthur early on July 2, 2014. Image Credit: NASA.

Tropical Storm Arthur appears to be ramping up, and NASA's Tropical Rainfall Measuring Mission or TRMM satellite spotted heavy rainfall occurring around the storm's center on July 1 when it was centered over the Bahamas.

Those heavy rains are expected to affect the southern U.S. coastline over the next several days as the National Hurricane Center expects Arthur to strengthen into a hurricane. On July 2, the NHC issued a Hurricane Watch for Bogue Inlet to Oregon Inlet, North Carolina and Pamlico Sound. In addition, a Tropical Storm Watch is in effect for the east coast of Florida from Sebastian Inlet to Flagler Beach, South Santee River South Carolina to south of  Bogue Inlet, North Carolina,  north of Oregon Inlet, North Carolina to the North Carolina/Virginia Border, and the Eastern Albemarle Sound.

Image above: GOES-West image of Arthur. Image Credit: NOAA/NASA GOES Project.

The TRMM satellite had a good daylight look at tropical storm Arthur on July 1, 2014 at 1620 UTC (12:20 p.m. EDT) less than two hours after it was upgraded from a tropical depression. At NASA's Goddard Space Flight Center in Greenbelt, Maryland rainfall from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data were overlaid on a GOES-East satellite infrared/visible image taken at 1626 UTC (12:26 p.m. EDT). The TMI instrument showed very heavy rainfall around Arthur's center. The heaviest rainfall was occurring at a rate of about 2 inches per hour. Powerful thunderstorms in that area reached heights above 15.5 km (about 9.6 miles).

Shortly after TRMM flew over Arthur and gathered rainfall and cloud height data, NASA's Terra satellite captured a visible image of the storm over the Bahamas. The image, created by the NASA Goddard MODIS Rapid Response Team, used visible data from the Moderate Resolution Imaging Spectroradiometer instrument that flies aboard Terra. The image showed a concentration of powerful storms around the center and northwestern quadrant of the storm. Arthur's western quadrant continued to affect the east coast of Florida.

Image above: NASA's Terra satellite captured this visible image of Tropical Storm Arthur on July 1 at 16:30 UTC (12:30 p.m. EDT) over the Bahamas. Image Credit: NASA Goddard MODIS Rapid Response Team.

On July 2 at 8 a.m. EDT (12:00 UTC) the center of Tropical Storm Arthur was near latitude 28.8 north and longitude 79.0 west. That's about 100 miles (160 km east-northeast of Cape Canaveral, Florida and NASA's Kennedy Space Center. Arthur's center is also 275 miles (445 km) south of Charleston, South Carolina.

The National Hurricane Center (NHC) noted that Arthur is moving toward the north near 6 mph (9 kph) and this motion is expected to continue today. A turn toward the north-northeast is expected tonight, July 2, followed by a turn toward the northeast. Maximum sustained winds remain near 60 mph (95 kph). Some strengthening is forecast during the next two days and Arthur is expected to become a hurricane by Thursday, July 3.

Image above: This image of rainfall occurring in Tropical Storm Arthur on July 1, 2014 at 12:20 p.m. EDT showed heavy rain (red) around the center of the storm. Image Credit: NASA/SSAI, Hal Pierce.

NHC noted that Arthur is expected to move east of the east-central coast of Florida today, July 2, pass east of Northeastern Florida tonight, move parallel to the coast of South Carolina on Thursday July 3, and approach the hurricane watch area Thursday night. For expected conditions along the watch areas, please visit the National Hurricane Center website: www.nhc.noaa.gov.

July 01, 2014 - Atlantic's Developing Tropical Depression 1

On June 29, 2014, at 7:06 p.m. EDT (2306 UTC) the Tropical Rainfall Measuring Mission, or TRMM, satellite flew over a low-pressure center east of Florida. This low-pressure area developed over South Carolina and moved east into the Atlantic Ocean where the warm waters of the Gulf Stream helped fuel it.

NASA's TRMM satellite uses different instruments that allow scientists on Earth to create 3-D images of those storms so they can see where the most powerful areas are within it. A NASA rainfall analysis made on June 29 that used data from TRMM's Microwave Imager and Precipitation Radar (PR) instruments showed that rainfall was only light to moderate near the center of the low.

Image above: The MODIS instrument aboard NASA's Aqua satellite captured this visible image of Tropical Depression 1 (01L) off the coast of central Florida on June 30 at 3 p.m. EDT. Image Credit: NASA Goddard MODIS Rapid Response Team.

At NASA's Goddard Space Flight Center in Greenbelt, Maryland, the TRMM science office also created a simulated 3-D view of rainfall using TRMM PR data that showed most of the convective (rising air that forms clouds and thunderstorms) showers and thunderstorms near the center of the low were only reaching altitudes of about 6.2 miles (about 10 km). A few of the outer rain bands contained powerful thunderstorm "hot towers," or towering clouds that reached heights of about 8 miles (13 km) indicating strong thunderstorms with heavy rainfall potential.

On June 30 at 3 p.m. EDT the Moderate Resolution Imaging Spectroradiometer instrument aboard NASA's Aqua satellite captured an impressive visible image of Tropical Depression 1 off the coast of central Florida. The image showed some powerful, high thunderstorms over the Bahamas. In visible imagery, the strongest thunderstorms are identified as the highest ones that cast shadows on the clouds below them.

On July 1 that area of low pressure developed into Tropical Depression 1. The National Hurricane Center issued a Tropical Storm Watch for the east coast of Florida from Fort Pierce to Flagler Beach.

Image above: NASA's TRMM satellite showed showers and thunderstorms near the center of the low near 6.2 miles. A few of the outer rain bands contained thunderstorms as high as 8 miles (red) indicating strong storms with heavy rainfall potential. Image Credit: NASA/Hal Pierce, SSAI.

The National Hurricane Center (NHC) noted at 8 a.m. EDT (1200 UTC) that the center of Tropical Depression 1 was located near 27.5 degrees north latitude and 79.2 degrees west longitude. That's just about 95 miles (155 km) southeast of Cape Canaveral, Florida. The depression has remained nearly stationary during the past few hours. A northwestward motion is expected to begin later today, followed by a turn toward the north on Wednesday. Maximum sustained winds are near 35 mph (55 kph). The estimated minimum central pressure is 1007 millibars.

NHC noted that the depression may become a tropical storm later in the day on July 1.   The system is forecast to pass east of northeastern Florida on Wednesday, July 2. For updates, visit the National Hurricane Center webpage: http://www.nhc.noaa.gov.

For more information about Tropical Rainfall Measuring Mission (TRMM), visit: http://trmm.gsfc.nasa.gov/

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

Greetings, Orbiter.ch

Ocean on Saturn Moon Could be as Salty as the Dead Sea

NASA / ESA - Cassini-Huygens Mission to Saturn & Titan patch.

July 2, 2014

Scientists analyzing data from NASA’s Cassini mission have firm evidence the ocean inside Saturn's largest moon, Titan, might be as salty as the Earth's Dead Sea.

The new results come from a study of gravity and topography data collected during Cassini's repeated flybys of Titan during the past 10 years. Using the Cassini data, researchers presented a model structure for Titan, resulting in an improved understanding of the structure of the moon's outer ice shell. The findings are published in this week’s edition of the journal Icarus.

"Titan continues to prove itself as an endlessly fascinating world, and with our long-lived Cassini spacecraft, we’re unlocking new mysteries as fast as we solve old ones," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, who was not involved in the study.

Additional findings support previous indications the moon's icy shell is rigid and in the process of freezing solid. Researchers found that a relatively high density was required for Titan's ocean in order to explain the gravity data. This indicates the ocean is probably an extremely salty brine of water mixed with dissolved salts likely composed of sulfur, sodium and potassium. The density indicated for this brine would give the ocean a salt content roughly equal to the saltiest bodies of water on Earth.

Image above: Researchers found that Titan's ice shell, which overlies a very salty ocean, varies in thickness around the moon, suggesting the crust is in the process of becoming rigid. Image Credit: NASA/JPL/SSI/Univ. of Arizona/G. Mitri/University of Nantes.

"This is an extremely salty ocean by Earth standards," said the paper's lead author, Giuseppe Mitri of the University of Nantes in France. "Knowing this may change the way we view this ocean as a possible abode for present-day life, but conditions might have been very different there in the past."

Cassini data also indicate the thickness of Titan's ice crust varies slightly from place to place. The researchers said this can best be explained if the moon's outer shell is stiff, as would be the case if the ocean were slowly crystalizing, and turning to ice. Otherwise, the moon's shape would tend to even itself out over time, like warm candle wax. This freezing process would have important implications for the habitability of Titan's ocean, as it would limit the ability of materials to exchange between the surface and the ocean.

A further consequence of a rigid ice shell, according to the study, is any outgassing of methane into Titan's atmosphere must happen at scattered "hot spots" -- like the hot spot on Earth that gave rise to the Hawaiian Island chain. Titan's methane does not appear to result from convection or plate tectonics recycling its ice shell.

Cassini spacecraft. Image Credit: NASA/JPL-Caltech

How methane gets into the moon's atmosphere has long been of great interest to researchers, as molecules of this gas are broken apart by sunlight on short geological timescales. Titan's present atmosphere contains about five percent methane. This means some process, thought to be geological in nature, must be replenishing the gas. The study indicates that whatever process is responsible, the restoration of Titan's methane is localized and intermittent.

"Our work suggests looking for signs of methane outgassing will be difficult with Cassini, and may require a future mission that can find localized methane sources," said Jonathan Lunine, a scientist on the Cassini mission at Cornell University, Ithaca, New York, and one of the paper's co-authors. "As on Mars, this is a challenging task."

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.

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

Images (mentioned), Text, Credits: NASA / Dwayne Brown / JPL / Preston Dyches.

Greetings, Orbiter.ch

Galactic Pyrotechnics on Display

NASA - Chandra X-ray Observatory patch.

July 2, 2014

A galaxy about 23 million light years away is the site of impressive, ongoing fireworks. Rather than paper, powder and fire, this galactic light show involves a giant black hole, shock waves and vast reservoirs of gas.

This galactic fireworks display is taking place in NGC 4258, also known as M106, a spiral galaxy like the Milky Way. This galaxy is famous, however, for something that our galaxy doesn’t have – two extra spiral arms that glow in X-ray, optical and radio light. These features, or anomalous arms, are not aligned with the plane of the galaxy, but instead intersect with it.

The anomalous arms are seen in this new composite image of NGC 4258, where X-rays from NASA’s Chandra X-ray Observatory are blue, radio data from the NSF’s Karl Jansky Very Large Array are purple, optical data from NASA’s Hubble Space Telescope are yellow and infrared data from NASA’s Spitzer Space Telescope are red.

A new study made with Spitzer shows that shock waves, similar to sonic booms from supersonic planes, are heating large amounts of gas – equivalent to about 10 million suns. What is generating these shock waves? Researchers think that the supermassive black hole at the center of NGC 4258 is producing powerful jets of high-energy particles. These jets strike the disk of the galaxy and generate shock waves. These shock waves, in turn, heat the gas – composed mainly of hydrogen molecules – to thousands of degrees.

The Chandra X-ray image reveals huge bubbles of hot gas above and below the plane of the galaxy. These bubbles indicate that much of the gas that was originally in the disk of the galaxy has been heated and ejected into the outer regions by the jets from the black hole.

NASA's Chandra X-ray Observatory spacecraft

The ejection of gas from the disk by the jets has important implications for the fate of this galaxy. Researchers estimate that all of the remaining gas will be ejected within the next 300 million years – very soon on cosmic time scales – unless it is somehow replenished. Because most of the gas in the disk has already been ejected, less gas is available for new stars to form. Indeed, the researchers used Spitzer data to estimate that stars are forming in the central regions of NGC 4258, at a rate which is about ten times less than in the Milky Way galaxy.

The European Space Agency’s Herschel Space Observatory was used to confirm the estimate from Spitzer data of the low star formation rate in the central regions of NGC 4258. Herschel was also used to make an independent estimate of how much gas remains in the center of the galaxy. After allowing for the large boost in infrared emission caused by the shocks, the researchers found that the gas mass is ten times smaller than had been previously estimated.

Because NGC 4258 is relatively close to Earth, astronomers can study how this black hole is affecting its galaxy in great detail. The supermassive black hole at the center of NGC 4258 is about ten times larger than the one in the Milky Way and is consuming material at a faster rate, potentially increasing its impact on the evolution of its host galaxy.

These results were published in the June 20, 2014 issue of The Astrophysical Journal Letters and are available online. The authors are Patrick Ogle, Lauranne Lanz and Philip Appleton from the California Institute of Technology in Pasadena, California.

NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

The Astrophysical Journal Letters,  June 20, 2014 issue: http://arxiv.org/abs/1405.2040

View large image: http://chandra.harvard.edu/photo/2014/m106/

Chandra on Flickr: http://www.flickr.com/photos/nasamarshall/sets/72157606205297786/

For more information about Chandra X-ray Observatory, visit: http://www.nasa.gov/mission_pages/chandra/main/

Images, Text, Credits: X-ray: NASA/CXC/Caltech/P.Ogle et al; Optical: NASA/STScI; IR: NASA/JPL-Caltech; Radio: NSF/NRAO/VLA.

Cheers, Orbiter.ch

A Stellar Womb Shaped and Destroyed by its Ungrateful Offspring

ESO - European Southern Observatory logo.

2 July 2014

The Gum 15 star formation region

The little-known cloud of cosmic gas and dust called Gum 15 is the birthplace and home of hot young stars. Beautiful and deadly, these stars mould the appearance of their mother nebula and, as they progress into adulthood, will eventually also be the death of her.

This image was taken as part of  the ESO Cosmic Gems programme [1] using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. It shows Gum 15, located in the constellation of Vela (The Sails), some 3000 light-years from Earth [2]. This glowing cloud is a striking example of an HII region [3]. Such clouds form some of the most spectacular astronomical objects we can see; for example the Eagle Nebula (which includes the feature nicknamed “The Pillars of Creation”), the great Orion Nebula, and this less famous example, Gum 15.

Gum 15 in the constellation of Vela

Hydrogen (H) is the most common element in the Universe, and can be found in virtually every environment investigated by astronomers. HII regions are different because they contain substantial amounts of ionised hydrogen — hydrogen atoms that have been stripped of their electrons through high energy interactions with ultraviolet photons — particles of light. As the ionised hydrogen nuclei recapture electrons they release light at different characteristic wavelengths. It is one of these that gives nebulae such as Gum 15 their reddish glow — a glow which astronomers call hydrogen alpha (Hα).

A wide-field view of the Gum 15 star formation region

In HII regions the ionising photons come from the young hot stars within the region, and Gum 15 is no exception. At the centre of this image you can see one of the culprits: the star HD 74804, the brightest member of a cluster of stars known as Collinder 197.

Zooming in on Gum 15

The clumpy, irregular appearance that enhances this nebula’s beauty is not unusual for a HII region and is again a result of the stars within. HII regions have diverse shapes because the distribution of stars and gas inside them is so irregular. Adding to Gum 15’s interesting shape are the forked dark patch of obscuring dust visible in the centre of this image and some dim blue reflection structures crossing it. This dust feature makes the nebula resemble a larger and fainter version of the better known Trifid Nebula (Messier 20), although in this case the name Bifid Nebula might be more apposite.

Panning across the star formation region Gum 15

An HII region like this one might give birth to thousands of stars over a period of several million years. Some of these stars cause it to glow and sculpt its shape, and it is these stars that will eventually destroy it. Once the newly minted stars have passed through their infant stages, strong winds of particles will stream away from these large stars, sculpting and dispersing the gases around them, and when the most massive of these stars begin to die, Gum 15 will die with them. Some stars are so large that they will go out with a bang, exploding as supernovae and dispersing the regions last traces of HII, leaving behind just a cluster of infant stars.

Notes:

[1] The ESO Cosmic Gems programme is an initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.

[2] The name of this object comes from the Australian astronomer Colin Gum, who published a catalogue of HII regions in 1955.

[3] HII regions (pronounded “aitch-two”) are large clouds of gas and dust that are host to bursts of star formation and homes to infant stars.

More information:

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Photos of the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&subject_name=mpg

Other photos taken with the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&facility=15

Photos of La Silla: http://www.eso.org/public/images/archive/category/lasilla/

Images, Text, Credits: ESO / IAU and Sky & Telescope / Digitized Sky Survey 2. Acknowledgement: Davide De Martin / Videos: ESO/Digitized Sky Survey 2/Nick Risinger (skysurvey.org). Music: movetwo. Acknowledgement: Davide De Martin.

Best regards, Orbiter.ch

OCO-2 Lifts Off on Carbon-Counting Mission

NASA - OCO-2 Mission logo.

July 2, 2014

Image above: A Delta II rocket leaps off the launch pad to begin NASA's OCO-2 mission at Vandenberg Air Force Base in California. Image Credit: NASA/Bill Ingalls.

A Delta II rocket blazed off the launch pad at Vandenberg Air Force Base in California early Wednesday morning to begin a landmark mission to survey carbon dioxide gas in Earth's atmosphere.

NASA's Orbiting Carbon Observatory-2, or OCO-2, is expected to provide insight into how the planet adjusts to the increased production of carbon dioxide from a vantage point in orbit that will allow it to take readings on a scale never achieved before.

Liftoff of OCO-2

While ground stations have been monitoring carbon dioxide concentrations, OCO-2 will be the first spacecraft to conduct a global-scale reading over several seasons. The spacecraft is expected to produce detailed readings to provide regional sources of carbon dioxide as well as sinks for the greenhouse gas.

"There's quite a lot of urgency to see what we can get from a satellite like OCO-2," said David Crisp, the science team lead for the mission.

The spacecraft flew into orbit aboard a United Launch Alliance Delta II rocket launched from Vandenberg Air Force Base in California. The July 2 liftoff came at 5:56 a.m. Eastern time, 2:56 Pacific time. The hexagonal spacecraft is about 6 feet long and 3 feet in diameter and weighs 985 pounds. The Delta II first stage's single liquid-fueled engine ignited moments before the three solid-fueled boosters roared to life to catapult the rocket and spacecraft off the pad toward space.

OCO-2 to Shed Light on Global Carbon Cycle

The launch was from the west coast so the spacecraft could enter a polar orbit of the Earth, a flight path that will see it cross over the Arctic and Antarctic regions during each revolution and get a complete picture of the Earth. It will fly about 438 miles above the planet's surface to take its readings.

"The only way to accomplish a polar orbit from U.S. soil is to launch from Vandenberg," said Tim Dunn, NASA's launch manager for the flight.

The mission is the first of its kind in the agency's extensive history of Earth-observing spacecraft. The spacecraft was launched to replace the first OCO that did not make it into orbit due to an anomaly in February 2009. The spacecraft carries one instrument and its sole focus is detecting carbon dioxide and watching from space as the Earth "breathes" to see what becomes of the gas.

The instrument is precise enough that researchers will be able to count the number of carbon dioxide molecules in the layers of the atmosphere and use the data to draw conclusions about how the increasing amount of gas will affect things like the global temperature. OCO-2's mission is to last at least two years.

Image above: Technicians and engineers work with the OCO-2 spacecraft during processing inside a facility at Vandenberg Air Force Base in California. Image Credit: NASA/Air Force 30th Space Wing.

NASA's Launch Services Program, based at Kennedy Space Center in Florida, managed the launch preparation and flight into orbit. The OCO-2 mission is handled by the Jet Propulsion Laboratory in California.

"We've been preparing for the OCO-2 mission for almost two years now," Dunn said before launch. "The biggest challenge has been in bringing the Delta II launch vehicle out of retirement. The last time we launched on a Delta II was October 2011, a weather satellite."

NASA's OCO-2 satellite in orbit. Image Credit: NASA / JPL

The Delta II has been one of NASA's most reliable launchers ever, registering more than 150 launches for NASA, the Air Force and commercial satellite makers from 1989 to 2011.

The launch team has been visiting Vandenberg during the preparation and spent the two weeks before launch there, running through the last phases of processing and countdown rehearsals.

With the mission safely begun, Dunn congratulated the team soon after OCO-2 separated from the Delta II's second stage and opened its pair of solar array wings.

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

For more information about OCO-2, visit: http://www.nasa.gov/oco2

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