vendredi 7 août 2015

Meals Ready to Eat: Expedition 44 Crew Members Sample Leafy Greens Grown on Space Station










ISS - Expedition 44 Mission patch.

Aug. 7, 2015

Fresh food grown in the microgravity environment of space officially is on the menu for the first time for NASA astronauts on the International Space Station. Expedition 44 crew members, including NASA's one-year astronaut Scott Kelly, are ready to sample the fruits of their labor after harvesting a crop of "Outredgeous" red romaine lettuce Monday, Aug. 10, from the Veggie plant growth system on the nation’s orbiting laboratory.

The astronauts will clean the leafy greens with citric acid-based, food safe sanitizing wipes before consuming them. They will eat half of the space bounty, setting aside the other half to be packaged and frozen on the station until it can be returned to Earth for scientific analysis.


Image above: Astronauts on the International Space Station are ready to sample their harvest of a crop of "Outredgeous" red romaine lettuce from the Veggie plant growth system that tests hardware for growing vegetables and other plants in space. Image Credit: NASA.

NASA's plant experiment, called Veg-01, is being used to study the in-orbit function and performance of the plant growth facility and its rooting "pillows," which contain the seeds.

NASA is maturing Veggie technology aboard the space station to provide future pioneers with a sustainable food supplement – a critical part of NASA’s Journey to Mars. As NASA moves toward long-duration exploration missions farther into the solar system, Veggie will be a resource for crew food growth and consumption. It also could be used by astronauts for recreational gardening activities during deep space missions.

The first pillows were activated, watered and cared for by Expedition 39 flight engineer Steve Swanson in May 2014. After 33 days of growth, the plants were harvested and returned to Earth in October 2014. At NASA’s Kennedy Space Center in Florida, the plants underwent food safety analysis. The second Veg-01 plant pillows were activated by Kelly on July 8 and grew again for 33 days before being harvested. The seeds had been on the station for 15 months before being activated.

The Veggie system was developed by Orbital Technologies Corp. (ORBITEC) in Madison, Wisconsin, and tested at Kennedy before flight. Veggie, along with two sets of pillows containing the romaine seeds and one set of zinnias, was delivered to the station on the third cargo resupply mission by SpaceX in April 2014.


Image above: NASA plans to grow food on future spacecraft and on other planets as a food supplement for astronauts. Fresh food, such as vegetables, provide essential vitamins and nutrients that will help enable sustainable deep space pioneering. Image Credit: NASA.

The collapsible and expandable Veggie unit features a flat panel light bank that includes red, blue and green LEDs for plant growth and crew observation. Using LED lights to grow plants was an idea that originated with NASA as far back as the late 1990s, according to Dr. Ray Wheeler, lead for Advanced Life Support activities in the Exploration Research and Technology Programs Office at Kennedy.

Wheeler worked with engineers and collaborators to help develop the Veggie unit from a Small Business Innovative Research project with ORBITEC. Dr. Gioia Massa is the NASA payload scientist for Veggie at Kennedy. Massa and others worked to get the flight unit developed and certified for use on the space station. The purple/pinkish hue surrounding the plants in Veggie is the result of a combination of the red and blue lights, which by design emit more light than the green LEDs. Green LEDS were added so the plants look like edible food rather than weird purple plants.

"Blue and red wavelengths are the minimum needed to get good plant growth," Wheeler said. "They are probably the most efficient in terms of electrical power conversion. The green LEDs help to enhance the human visual perception of the plants, but they don't put out as much light as the reds and blues."

Wheeler, Massa and Dr. Gary Stutte, all from Kennedy, previously investigated similar experiments to grow plants in the Habitat Demonstration Unit at NASA's desert test site near Flagstaff, Arizona, in 2010 and 2011. Wheeler said Veggie will help NASA learn more about growing plants in controlled environment agriculture settings. Similar settings include vertical agriculture, which refers to stacking up shelves of plants that are grown hydroponically and then using electric light sources like red and blue LEDs. This kind of system is popular in some Asian countries and beginning to grow in the U.S.


Image above: (Interior view) NASA plans to grow food on future spacecraft and on other planets as a food supplement for astronauts. Fresh food, such as vegetables, provide essential vitamins and nutrients that will help enable sustainable deep space pioneering. Image Credit: NASA.

"There is evidence that supports fresh foods, such as tomatoes, blueberries and red lettuce are a good source of antioxidants. Having fresh food like these available in space could have a positive impact on people's moods and also could provide some protection against radiation in space," Wheeler said.

After the first crop of lettuce was returned from the space station, Massa began working with a team of flight doctors and NASA safety representatives to get approval for the crew to eat the produce.

"Microbiological food safety analysis looks very good on the first Veg-01 crop of romaine lettuce," Massa said.

Besides the nutritional benefits, could growing fresh produce in space also provide a psychological benefit? Alexandra Whitmire, a scientist at NASA’s Johnson Space Center in Houston is involved in research to answer that question.

Whitmire is the Behavioral Health and Performance Research scientist for NASA's Human Research Program. Her team supports research related to reducing psychological risks on a Mars mission.

"The Veggie experiment is currently the only experiment we are supporting which involves evaluating the effects of plant life on humans in space," Whitmire said.

Her team is focused on crew behavioral conditions, performance reduction, and team communication and psychosocial adaption.

Space Station Live: Lettuce Look at Veggie

Video above: Paul Zamprelli of Orbitec, the company that developed the Veggie greenhouse, describes the hardware that supports plant growth and, for the first time, crew consumption of lettuce on the International Space Station. Video Credit: NASA TV.

"Future spaceflight missions could involve four to six crew members living in a confined space for an extended period of time, with limited communication," Whitmire said. "We recognize it will be important to provide training that will be effective and equip the crew with adequate countermeasures during their mission."

The countermeasures could include things like meaningful work. Habitat-related modifications also could include plant life. Whitmire said Earth studies have shown plants are associated with well-being and optimal performance. Plants potentially could serve as a countermeasure for long-duration exploration missions.

Massa agrees: "Besides having the ability to grow and eat fresh food in space, there also may be a psychological benefit. The crew does get some fresh fruits or vegetables, such as carrots or apples, when a supply ship arrives at the space station. But the quantity is limited and must be consumed quickly."

Having something green and growing--a little piece of Earth--to take care of when living and working in an extreme and stressful environment could have tremendous value and impact.

International Space Station (ISS). Image Credit: NASA

"The farther and longer humans go away from Earth, the greater the need to be able to grow plants for food, atmosphere recycling and psychological benefits. I think that plant systems will become important components of any long-duration exploration scenario," Massa said.

The system also may have implications for improving growth and biomass production on Earth, thus benefiting the average citizen. Massa said many of the lessons NASA is learning with Veggie could be applied in urban plant factories and other agriculture settings where light is provided by electrical light and water conservation is practiced.

"We hope to increase the amount and type of crop in the future, and this will allow us to learn more about growing plants in microgravity," Massa said. "We have upcoming experiments that will look at the impacts of light quality on crop yield, nutrition and flavor, both on Earth and in space."

The team at Kennedy and Johnson hope that Veggie and space gardening will become a valued feature of life aboard the space station and in the future on Mars.

For more information about Veggie, visit here: http://www.nasa.gov/mission_pages/station/research/experiments/383.html

Related links:

International Space Station (ISS): http://www.nasa.gov/mission_pages/station/research/index.html

one-year Mission: https://www.nasa.gov/content/one-year-crew

Journey to Mars: https://www.nasa.gov/content/nasas-journey-to-mars

NASA's Human Research Program: https://www.nasa.gov/hrp

NASA’s Kennedy Space Center: http://www.nasa.gov/centers/kennedy/home/index.html

NASA’s Johnson Space Center: http://www.nasa.gov/centers/johnson/home/index.html

Images (mentioned), Video (mentioned), Text, Credits: NASA Kennedy Space Center/Linda Herridge/Kristine Rainey.

Best regards, Orbiter.ch

First release of Rosetta comet phase data from four orbiter instruments












ESA - Rosetta Mission patch.

Aug. 7, 2015

ESA’s Rosetta downlink and archive teams are very happy to announce the release today of the first wave of Rosetta instrument data from the “comet pre-landing phase” via the Planetary Science Archive. Data from four instruments are included in this release: COSIMA, OSIRIS, ROSINA, and RPC-MAG.

After Rosetta woke up from 31 months hibernation in January 2014, its scientific instruments were turned back on and checked out before being used to study Comet 67P/Churyumov-Gerasimenko during the approach, rendezvous, and escort phases.

As agreed between ESA and the funding bodies responsible for Rosetta’s instruments, their data are initially made available to the corresponding scientific teams for first analysis, with a significant number of Rosetta papers published based on these data, as described in previous blog posts.

After a nominal period of 6 months, the scientific data themselves are to be delivered to ESA to be placed in the public domain via the Planetary Science Archive (PSA) for use by all scientists and the wider public. In practice, it was agreed to deliver data to ESA for release in blocks, and the first of those blocks was defined as the ‘pre-landing phase’, i.e. covering the period from January 2014 to just after Philae’s landing on the comet in mid-November 2014.

This led to a date of 19 May for the instrument teams to deliver the data from that phase to ESA, following which, a very significant effort had to be made by the ESA team to process the datasets of the many instruments involved and prepare them for release.

What did this processing entail? Firstly, the data and the associated metadata had to be checked for completeness and for compliance with standard formats to ensure that they can be downloaded and analysed by other scientists in a transparent manner.

Rosetta's instruments. Credit: ESA/ATG medialab

This involved interactions between all of the instrument teams, the ESAC-based downlink and archive teams, and the Planetary Data System (PDS – Small Bodies Node) team located in the US to ensure the data format and contents complied with the PDS standards.

These complex checks and interactions have taken quite some time, in part because this was the first major data delivery from the comet phase to ESA from the whole instrument suite. For some instruments, the datasets are vast, with up to 8 months of scientific measurements, pushing processing systems to the limit. In the majority of cases, this procedure has necessitated updates to an instrument’s data pipeline, resulting in the need for the data to be re-processed, re-delivered, and checked once more.

Today sees the first release of pre-landing phase data from four of Rosetta’s instruments, representative of the wide scientific scope of the orbiter. COSIMA collects and analyses dust grains around the comet; OSIRIS uses its Narrow and Wide Angle Cameras to take multi-wavelength visible and near-infrared images of the nucleus, activity rising from its surface, and the immediate coma; ROSINA has two mass spectrometers to sniff and analyse the gases and RPC-MAG studies the magnetic field in the environment of the comet.

The data being released are described in more detail below:

COSIMA (COmetary Secondary Ion Mass Analyser)

This dataset includes images of dust particles collected in the environment of Comet 67P/C-G from the nucleus approach phase until 19 November 2014, along with secondary ion mass spectra for some of those particles.

OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System)

This dataset covers the first part of the pre-landing phase from 20 March to 12 June 2014, comprising four sets each for the Narrow Angle Camera and the Wide Angle Camera, and consisting of 2203 images in total. It contains the early light curve observations used to make a precise determination of rotation period and orientation of the rotation axis of Comet 67P/C-G. It also includes the outburst observed in April/May 2014 and the development of the dusty coma around the cometary nucleus. The data were processed with the new, re-developed OSIRIS calibration pipeline including recent updates from the in-flight calibration campaigns.

ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis)

This dataset covers the period March to November 2014, and contains 100 Gbytes of data consisting of 685,234 tables and 1.3 billion rows. These are currently “level 2” data, meaning more or less as received from the spacecraft, followed by decompression and the addition of metadata including the distance to the comet, direction of the Sun, and the spacecraft pointing. Future releases will be at a higher, more directly usable level containing mass spectra with physical units (e.g. detected particles vs. mass); further work is necessary to ensure that this is achieved in a consistent manner.

RPC-MAG (Rosetta’s Plasma Consortium MAGnetometer)

This dataset contain time series of the magnetic field measurements made in situ on Rosetta. RPC-MAG comprises two tri-axial fluxgate magnetometers that are able to register the three components of the magnetic field vector at a maximum sampling rate of 20 Hz. Observations have been made quasi permanently since May 2014, and the dataset covers from then until 19 November. Further processing of the data is on-going in order to reduce contamination due to changing spacecraft bias fields.

Access to these instrument datasets can be made here: http://www.sciops.esa.int/index.php?project=PSA

OSIRIS images added to Archive Image Browser

In addition to the data being released today to the PSA, the downlink and archive team is pleased to release an update of the Archive Image Browser http://imagearchives.esac.esa.int/. As well as images from Rosetta’s NAVCAM, this “easy access tool” now includes OSIRIS images from the Earth, Mars, and asteroid fly-bys that occurred between 2005 and 2010 en-route to the comet, and a “first processed” version of the images from today’s pre-landing phase release. Further processing of the OSIRIS pre-landing images in the image browser will be performed in the mid-late August timeframe.


Image above: Screenshot from ESA's Archive Image Browser showing OSIRIS cruise phase albums.

Upcoming data deliveries

While it has taken quite some time to process and release all the pre-landing datasets delivered, we anticipate that future processing will be more efficient and timely. The Philae lander instrument teams have delivered the data that formed the basis of the seven papers published in Science last week, and the next comet phase data delivery from the orbiter instrument teams is planned for mid-September (covering 19-Nov to 10-Mar 2015). With the corrected pipelines now producing data formats consistent with the archive standards, we expect to be able to archive and release those data more rapidly thereafter. The aim is to have the current Rosetta and Philae datasets released by mid-September.

It is important to realise that even after today’s first release, this process remains a work-in-progress. As more is learned about the calibration of the various instruments from in-flight measurements, and as feedback is received from the instrument teams and external users, these data may be re-processed and released again into the archives. This is standard practice and ensures that the data found in the archives always reflect the current best understanding of the complex instruments that produced them. A case in point is the current OSIRIS dataset, where issues still remain with their pipeline: a second version will be released to the PSA by September to correct for such problems.

Beyond the formal validation steps, a scientific review of these Rosetta pre-landing data is scheduled to take place at the beginning of 2016. This review will assess the scientific usefulness of the data and may lead to updates being made to various instrument datasets to incorporate proposed improvements in this regard.

At a higher level, the goal of the activities described in this post is to ensure that the products entering the archive are well documented and remains compatible with changing computer hard- and software systems, so that they can be used far into the future,

For example, we can now retrieve archival data from Giotto’s mission to Comet Halley in 1986 and re-analyse it with Rosetta’s discoveries in mind. We are still finding valuable and surprising information in these old data, which in turn enhances the science return from Rosetta. But the prerequisite for this is to adhere to very strict rules: a difficult task but worthwhile in the long run to maximise the legacy of the Rosetta mission.

For more information about Rosetta mission, visit: http://www.esa.int/Our_Activities/Space_Science/Rosetta

Where is Rosetta?: http://sci.esa.int/where_is_rosetta/

Rosetta overview: http://www.esa.int/Our_Activities/Space_Science/Rosetta_overview

Rosetta in depth:http://sci.esa.int/rosetta

Rosetta factsheet: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_factsheet

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions

Images (mentioned), Text, Credits: European Space Agency (ESA).

Greetings, Orbiter.ch

Hubble Finds a Little Gem











NASA - Hubble Space Telescope patch.

Aug. 7, 2015


This colorful bubble is a planetary nebula called NGC 6818, also known as the Little Gem Nebula. It is located in the constellation of Sagittarius (The Archer), roughly 6,000 light-years away from us. The rich glow of the cloud is just over half a light-year across — humongous compared to its tiny central star — but still a little gem on a cosmic scale.

When stars like the sun enter "retirement," they shed their outer layers into space to create glowing clouds of gas called planetary nebulae. This ejection of mass is uneven, and planetary nebulae can have very complex shapes. NGC 6818 shows knotty filament-like structures and distinct layers of material, with a bright and enclosed central bubble surrounded by a larger, more diffuse cloud.

Scientists believe that the stellar wind from the central star propels the outflowing material, sculpting the elongated shape of NGC 6818. As this fast wind smashes through the slower-moving cloud it creates particularly bright blowouts at the bubble’s outer layers.

Hubble orbiting Earth

Hubble previously imaged this nebula back in 1997 with its Wide Field Planetary Camera 2, using a mix of filters that highlighted emission from ionized oxygen and hydrogen. This image, while from the same camera, uses different filters to reveal a different view of the nebula.

For additional images and more information about Hubble, visit:

http://www.nasa.gov/hubble
http://hubblesite.org/
http://www.spacetelescope.org/

Image Credits: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt/Text credit: European Space Agency/Ashley Morrow.

Best regards, Orbiter.ch

Cruise Over Ceres in New Video












NASA - Dawn Mission patch.

August 7, 2015

Striking 3-D detail highlights a towering mountain, the brightest spots and other features on dwarf planet Ceres in a new video from NASA's Dawn mission.

Tour Weird Ceres: Bright Spots and a Pyramid-Shaped Mountain

Video above: This video shows a series of animations of dwarf planet Ceres, generated from data from NASA's Dawn spacecraft. Video Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/LPI.

A prominent mountain with bright streaks on its steep slopes is especially fascinating to scientists. The peak's shape has been likened to a cone or a pyramid. It appears to be about 4 miles (6 kilometers) high, with respect to the surface around it, according to the latest estimates. This means the mountain has about the same elevation as Mount McKinley in Denali National Park, Alaska, the highest point in North America.


Image above: The intriguing brightest spots on Ceres lie in a crater named Occator, which is about 60 miles (90 kilometers) across and 2 miles (4 kilometers) deep. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/LPI.

"This mountain is among the tallest features we've seen on Ceres to date," said Dawn science team member Paul Schenk, a geologist at the Lunar and Planetary Institute, Houston. "It's unusual that it's not associated with a crater. Why is it sitting in the middle of nowhere? We don't know yet, but we may find out with closer observations."

Also puzzling is the famous Occator (oh-KAH-tor) crater, home to Ceres' brightest spots. A new animation simulates the experience of a close flyover of this area. The crater takes its name from the Roman agriculture deity of harrowing, a method of pulverizing and smoothing soil.

In examining the way Occator's bright spots reflect light at different wavelengths, the Dawn science team has not found evidence that is consistent with ice. The spots' albedo -­ a measure of the amount of light reflected -­ is also lower than predictions for concentrations of ice at the surface.

"The science team is continuing to evaluate the data and discuss theories about these bright spots at Occator," said Chris Russell, Dawn's principal investigator at the University of California, Los Angeles. "We are now comparing the spots with the reflective properties of salt, but we are still puzzled by their source. We look forward to new, higher-resolution data from the mission's next orbital phase."


Image above: Among the highest features seen on Ceres so far is a mountain about 4 miles (6 kilometers) high, which is roughly the elevation of Mount McKinley in Alaska's Denali National Park. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/LPI.

An animation of Ceres' overall geography, also available in 3-D, shows these features in context. Occator lies in the northern hemisphere, whereas the tall mountain is farther to the southeast (11 degrees south, 316 degrees east).

"There are many other features that we are interested in studying further," said Dawn science team member David O'Brien, with the Planetary Science Institute, Tucson, Arizona. "These include a pair of large impact basins called Urvara and Yalode in the southern hemisphere, which have numerous cracks extending away from them, and the large impact basin Kerwan, whose center is just south of the equator."

Ceres is the largest object in the main asteroid belt between Mars and Jupiter. Thanks to data acquired by Dawn since the spacecraft arrived in orbit at Ceres, scientists have revised their original estimate of Ceres' average diameter to 584 miles (940 kilometers). The previous estimate was 590 miles (950 kilometers).

Dawn will resume its observations of Ceres in mid-August from an altitude of 900 miles (less than 1,500 kilometers), or three times closer to Ceres than its previous orbit.


Image above: This image of Ceres, taken by NASA's Dawn spacecraft, features a large, steep-sided mountain and several intriguing bright spots. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

On March 6, 2015, Dawn made history as the first mission to reach a dwarf planet, and the first to orbit two distinct extraterrestrial targets. It conducted extensive observations of Vesta in 2011-2012.

Dawn's mission is managed by NASA's Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: http://dawn.jpl.nasa.gov/mission

More information about Dawn is available at the following sites: http://dawn.jpl.nasa.gov and http://www.nasa.gov/dawn

Video (mentioned), Images (mentioned), Text, Credits: NASA/JPL/Elizabeth Landau.

Greetings, Orbiter.ch

jeudi 6 août 2015

Hubble Finds Evidence of Galaxy Star Birth Regulated by Black-Hole Fountain












NASA - Hubble Space Telescope patch.

Aug. 6, 2015

Astronomers have uncovered a unique process for how the universe’s largest elliptical galaxies continue making stars long after their peak years of star birth. NASA’s Hubble Space Telescope’s exquisite high resolution and ultraviolet-light sensitivity allowed the astronomers to see brilliant knots of hot, blue stars forming along the jets of active black holes found in the centers of giant elliptical galaxies.

Combining Hubble data with observations from a suite of ground-based and space telescopes, two independent teams found that that the black hole, jets, and newborn stars are all parts of a self-regulating cycle. High-energy jets shooting from the black hole heat a halo of surrounding gas, controlling the rate at which the gas cools and falls into the galaxy.


Images above: Top: Actual Hubble observations of gas density in the central portion of two galaxies. Bottom: Computer simulations of knots of star formation in the two galaxies show how gas falling into a galaxy's center is controlled by jets from the central black hole. Image Credits: NASA/ESA/M. Donahue/Y. Li.

“Think of the gas surrounding a galaxy as an atmosphere,” explained the lead of the first study, Megan Donahue of Michigan State University. “That atmosphere can contain material in different states, just like our own atmosphere has gas, clouds, and rain. What we are seeing is a process like a thunderstorm. As the jets propel gas outward from the center of the galaxy, some of that gas cools and precipitates into cold clumps that fall back toward the galaxy’s center like raindrops.”

“The ‘raindrops’ eventually cool enough to become star-forming clouds of cold molecular gas, and the unique far ultraviolet capabilities of Hubble allowed us to directly observe these ‘showers’ of star formation,” explained the lead of the second study, Grant Tremblay of Yale University. “We know that these showers are linked to the jets because they’re found in filaments and tendrils that wrap around the jets or hug the edges of giant bubbles that the jets have inflated,” said Tremblay, “And they end up making a swirling ‘puddle’ of star-forming gas around the central black hole.”

But what should be a monsoon of raining gas is reduced to a mere drizzle by the black hole. While some outwardly flowing gas will cool, the black hole heats the rest of the gas around a galaxy, which prevents the whole gaseous envelope from cooling more quickly. The entire cycle is a self-regulating feedback mechanism, like the thermostat on a house’s heating and cooling system, because the “puddle” of gas around the black hole provides the fuel that powers the jets. If too much cooling happens, the jets become more powerful and add more heat. And if the jets add too much heat, they reduce their fuel supply and eventually weaken.

This discovery explains the mystery of why many elliptical galaxies in the present-day universe are not ablaze with a higher rate of star birth. For many years, the question has persisted of why galaxies awash in gas don’t turn all of that gas into stars. Theoretical models of galaxy evolution predict that present-day galaxies more massive than the Milky Way should be bursting with star formation, but that is not the case.

Now scientists understand this case of arrested development, where a cycle of heating and cooling keeps star birth in check. A light drizzle of cooling gas provides enough fuel for the central black hole’s jets to keep the rest of the galaxy’s gas hot. The researchers show that galaxies don’t need fantastic and catastrophic events such as galaxy collisions to explain the showers of star birth they see.

Hubble Space Telescope. Image Credit: NASA

The study led by Donahue looked at far-ultraviolet light from a variety of massive elliptical galaxies found in the Cluster Lensing And Supernova Survey with Hubble (CLASH), which contains elliptical galaxies in the distant universe. These included galaxies that are raining and forming stars, and others that are not. By comparison, the study by Tremblay and his colleagues looked at only elliptical galaxies in the nearby universe with fireworks at their centers. In both cases, the filaments and knots of star-birth appear to be very similar phenomena. An earlier, independent study, led by Rupal Mittal of the Rochester Institute of Technology and the Max Planck Institute for Gravitational Physics, also analyzed the star-birth rates in the same galaxies as Tremblay’s sample.

The researchers were aided by an exciting, new set of computer simulations of the hydrodynamics of the gas flows developed by Yuan Li of the University of Michigan. “This is the first time we now have models in hand that predict how these things ought to look,” explains Donahue. “And when we compare the models to the data, there’s a stunning similarity between the star-forming showers we observe and ones that occur in simulations. We’re getting a physical insight that we can then apply to models.   

Along with Hubble, which shows where the old and the new stars are, the researchers used the Galaxy Evolution Explorer (GALEX), the Herschel Space Observatory, the Spitzer Space Telescope, the Chandra X-ray Observatory, the X-ray Multi-Mirror Mission (XMM-Newton), the National Radio Astronomy Observatory (NRAO)’s Jansky Very Large Array (JVLA), the National Optical Astronomy Observatory (NOAO)’s Kitt Peak WIYN 3.5 meter telescope, and the Magellan Baade 6.5 meter telescope. Together these observatories paint the complete picture of where all of the gas is, from the hottest to the coldest. The suite of telescopes shows how galaxy ecosystems work, including the black hole and its influence on its host galaxy and the gas surrounding that galaxy.

Donahue’s paper was published in the Astrophysical Journal on June 2, 2015. Tremblay’s paper was published in the Monthly Notices of the Royal Astronomical Society on June 29, 2015.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency (ESA). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington.

For additional images and more information about Hubble, visit:

http://www.nasa.gov/hubble
http://hubblesite.org/
http://www.spacetelescope.org/

Related article:

NASA’s Chandra Observatory Finds Cosmic Showers Halt Galaxy Growth (March 4, 2015): http://orbiterchspacenews.blogspot.ch/2015/03/nasas-chandra-observatory-finds-cosmic.html

Images (mentioned), Text, Credits: NASA/Space Telescope Science Institute/Ann Jenkins/Ray Villard/Rob Garner.

Greetings, Orbiter.ch

China is Building The World's Largest Telescope















Radio Telescope icon.


August 6, 2015

Arecibo Observatory in Puerto Rico

The Arecibo Observatory in Puerto Rico will soon lose its title of the largest single aperture radio telescope ever constructed. The Chinese are building a Five hundred meter Aperture Spherical Telescope, shortened to FAST, which when complete in 2016 will be the world's largest radio telescope and three times more sensitive than the Arecibo Observatory.

The telescope is being built in a remote part of Guizhou province in southern China, in an area that is “radio silent” as there are no towns and cities within a radius of 5 km and only one county centre within 25 km.

 Artist’s rendering of what FAST would look like when complete

The gigantic radio telescope will be placed in a natural crater-like depression and will consist of 4,600 triangular panels that could be moved to change the overall shape of the dish’s reflective surface, allowing it to scan large swathes of the sky.

Astronomers expect FAST to uncover thousands of new galaxies and deep-sky objects up to 7 billion light years away. FAST will probably remain the best in the world in the next twenty to thirty years after it is completed.

FAST Radio telescope under construction

The gigantic radio telescope will cost approximately 1.2 billion Yuan (£120 million), making it the biggest astronomy project China has ever had.

It will allow scientists to get weaker radio signals from outer space, even further than our solar system, reported People's Daily Online.

For more information about Five hundred meter Aperture Spherical Telescope (FAST), visit: (Wikipédia) https://fr.wikipedia.org/wiki/Five_hundred_meter_Aperture_Spherical_Telescope

Images, Text, Credits: SETI/American Scientist/Yibada/Orbiter.ch Aerospace.

Greetings, Orbiter.ch

Celebrating a year at the comet












ESA - Rosetta Mission patch.

6 August 2015

ESA’s Rosetta mission today celebrates one year at Comet 67P/Churyumov–Gerasimenko, with its closest approach to the Sun now just one week away.

It’s been a long but exciting journey for Rosetta since its launch in 2004, featuring Earth, Mars and two asteroid flybys before arriving at its ultimate destination on 6 August 2014. Over the following months, the mission became the first ever to orbit a comet and the first to soft land a probe – Philae – on its surface.

Living with a comet

The mission teams have had to overcome many challenges in learning to fly in an unpredictable and sometimes inhospitable environment, and the spacecraft has returned a wealth of outstanding scientific data from this intriguing comet, spanning its interior, the dramatic surface and the surrounding cloud of dust, gas and plasma.

“This mission is about scientific discovery and every day there is something new to wonder at and try to understand,” says Nicolas Altobelli, acting Rosetta project scientist.

“A year of observations near to the comet has provided us with a wealth of information about it, and we’re looking forward to another year of exploration.”

Arriving at a comet

Highlights thus far have included the discovery that the comet’s water vapour has a different ‘flavour’ to Earth’s oceans, fuelling the debate on the possible role of comets and asteroids in delivering water to our planet in its early history.

The first detection of molecular nitrogen in a comet provided important clues about the temperature environment in which the comet was ‘born’. Molecular nitrogen was common when the Solar System was forming, but required very low temperatures to become trapped in ice, so Rosetta’s measurements support the theory that comets originate from the cold and distant Kuiper Belt.

Descending to a comet

Data collected by Rosetta and Philae during the lander’s descent to the surface have allowed scientists to deduce that the comet’s nucleus is non-magnetised, at least on large scales. 

Although magnetic fields are thought to have played an important function in moving small, magnetised dust grains around in the infant Solar System, the Rosetta and Philae measurements show that they did not continue to play a significant role once the particles had agglomerated to form larger building blocks metres and tens of metres across.

These are just a few of the myriad examples of the scientific discoveries being made by Rosetta, and most of them come from data taken in the early part of the comet-phase activities.

Now the comet and spacecraft are a week from perihelion, the point on its 6.5-year orbit that takes it closest to the Sun. On 13 August, they will be 186 million kilometres from the Sun, about a third of the distance at rendezvous last August.

“The period around perihelion is scientifically very important, as the heat from the Sun and the resulting outflow of gas and dust build to a maximum, providing us with important insights into this key time in the overall life cycle of the comet,” says Nicolas.

“For example, surface changes may reveal fresh material that has yet to be altered by solar radiation or cosmic rays, giving us a window into the comet’s subsurface layers – this will be the first time ever in cometary exploration that surface changes can be monitored in relation with increased activity.”

Comet around perihelion

Rosetta has been watching its activity increase over the last months, as its frozen ices warm, turn to gas, and jet into space, dragging the comet’s dust along with it. Together, the gas and dust have created a fuzzy atmosphere, or coma, around the nucleus and a long tail stretching over 120 000 km into space that can only be seen from afar.

Rosetta has a unique ringside seat for studying where and how this activity arises on the surface of the comet. Earlier in 2015, the spacecraft approached to within just 6 km to carry out its measurements, but as the level of gas and dust has increased over the last few months, Rosetta has been studying the comet from safer distances, and is currently operating 250–300 km away.

“As we’ve been approaching perihelion, near-comet operations have proven to be especially challenging: the increasing level of cometary dust confuses Rosetta’s startrackers and without them working properly Rosetta can’t position itself in space,” says Rosetta Spacecraft Operations Manager, Sylvain Lodiot.

“All the teams involved, including flight control, flight dynamics and science operations, have had to learn to adapt to these conditions ‘on the fly’. We have had to fully rethink how we operate the spacecraft, and plan science activities on timescales of just a few days or weeks. This has been a major challenge, but it certainly makes the mission even more exciting.”

Comet on 30 July 2015 – NavCam

One important aspect of Rosetta’s long-term study will be to watch how the activity subsides again in the months following perihelion. The hope is that Rosetta will eventually be able to get closer to the nucleus again and see how the surface changed during its close encounter with the Sun.

“One year after arriving, Rosetta has accumulated a number of impressive successes, from the landing of Philae, to the many scientific discoveries that are being made and published,” says Patrick Martin, Rosetta Mission Manager.

“The scientific harvest is set to continue into next year as we watch the comet’s post-perihelion behaviour, ahead of Rosetta’s grand finale in September 2016, when we plan to land the orbiter on the comet.”

Notes for Editors:


A Google+ Hangout celebrating a year at the comet and perihelion is scheduled for 13:00–15:00 GMT (15:00–17:00 CEST) on 13 August 2015. Watch here: https://plus.google.com/events/cl01p03as680jn4iflpp1hmdbr4

Browse our new “Year at a comet” image gallery here: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Highlights/Year_at_a_comet

Learn more about perihelion in our FAQ here: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_preparing_for_perihelion

About Rosetta:

Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta’s Philae lander is contributed by a consortium led by DLR, MPS, CNES and ASI.

Related article:

Rosetta: preparing for perihelion: http://orbiterchspacenews.blogspot.ch/2015/07/rosetta-preparing-for-perihelion.html

Related links:

For more information about Rosetta mission, visit: http://www.esa.int/Our_Activities/Space_Science/Rosetta

Where is Rosetta?: http://sci.esa.int/where_is_rosetta/

Rosetta overview: http://www.esa.int/Our_Activities/Space_Science/Rosetta_overview

Rosetta in depth:http://sci.esa.int/rosetta

Rosetta factsheet: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_factsheet

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions

Images, Text, Credits: ESA/Rosetta/Navcam/Philae/ROLIS/DLR/CC BY-SA IGO 3.0.

Best regards, Orbiter.ch

mercredi 5 août 2015

Gemini V: Paving the Way for Long Duration Spaceflight












NASA - Gemini Program logo.

Aug. 5, 2015

Launch of Gemini V mission. Image Credit: NASA

During the summer of 1965, the United States began to pull even in the space race with the Soviet Union. The eight-day Gemini V endurance mission doubled America's spaceflight record set two months earlier. It also tested technology that would help make longer missions possible in the future.

One of the lasting benefits of NASA's Gemini Program was its sustained technological investments accumulated over a two-year period. These new capabilities allowed astronauts not only to meet the challenges for landing on the moon, but laid the groundwork for long-duration missions aboard the International Space Station and future flights to destinations that still await, such as a near-Earth asteroid and Mars.


Image above: Gemini V pilot Charles "Pete" Conrad, left, and command pilot Gordon Cooper stand in front of Cape Kennedy's Launch Pad 19 during a training exercise on Aug. 16, 1965. Image Credit: NASA.

Now, 50 years after Gemini V, NASA astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko are in the midst of a one-year stay in orbit aboard the space station. With the doubling of the length of the usual ISS stay, researchers hope to better understand how the human body reacts and adapts to longer-duration spaceflight. This knowledge is crucial as NASA looks toward human journeys to and from Mars, which could last 500 days or longer.

In addition to efforts to determine microgravity's effects after more than a week in orbit, the crew of Gordon Cooper and first-time astronaut Charles "Pete" Conrad planned to attempt to catch up with an instrument package called the rendezvous evaluation pod (REP).


Images above: Gemini V was the first mission to have a crew insignia. The original version, left, featured a Conestoga covered wagon noting the pioneering effort of Gemini. On the side was the slogan "8 Days or Bust." After reviewing the design, NASA Administrator James Webb approved the concept, but expressed reservations about the slogan which was subsequently covered up on the version worn by the astronauts for the flight. Images Credit: NASA.

A member of the original seven Mercury astronauts, Cooper flew more than 34 hours and orbited the Earth 22 times on Mercury 9 during May 1963. Conrad was a member of the agency's second group of astronauts. He would go on to command Gemini 11 in 1966, walk on the moon during Apollo 12 in 1969 and lead the first Skylab crew in May and June 1973.

As flights became longer and more complex, the NASA team at the Kennedy Space Center and Cape Kennedy (now Cape Canaveral) Air Force Station intensified its efforts to ensure mission success. The Florida spaceport's NASA test conductor for Gemini V was Chuck Gay. He and a team of specialists conducted nine weeks of capsule factory tests and inspections at the McDonnell Aircraft Corp. in St. Louis where the spacecraft was built. The capsule then was flown to Kennedy for another eight weeks of prelaunch checkouts.


Image above: Gemini V pilot Charles "Pete" Conrad inside the Gemini V spacecraft as it orbited Earth between Aug. 21 through 29, 1965. Image Credits: NASA/Gordon Cooper.

"A great deal of knowledge was gained during the four previous Gemini missions, particularly the two manned flights," Gay said in a 1965 interview. "Extremely rigid specifications were tightened even further for Gemini 5, and inspection procedures were more stringent than those previously used."

He noted that the scrutiny was due to the new, untested procedures planned for the upcoming flight.

"Gemini V will demonstrate an eight-day long-duration capability for both the spacecraft and crew," he said. "In addition, this will be the first use of fuel cells for supplying spacecraft power during a manned flight."


Image above: This view of the lower tip of Baja California and Bahia de la Paz was taken from the Gemini V spacecraft. The nose of the Gemini is in the lower right. Image Credits: NASA/Gordon Cooper.

A fuel cell converts energy from a fuel, such as liquid hydrogen, into electricity through a chemical reaction with liquid oxygen or another oxidizing agent. By comparison, a battery stores the chemical reactants. Once used up, a battery must be recharged or discarded. A fuel cell will continue to produce electricity as long as it has a fuel supply, a crucial technology for long-duration spaceflights.

Gemini V astronauts Cooper and Conrad also were the first to design an insignia patch for their flight. The original version featured a Conestoga covered wagon, noting the pioneering effort of Gemini. On the side was the slogan "8 Days or Bust."

After the design was submitted for review to NASA Administrator James Webb, he wrote Director of Flight Crew Operations Deke Slayton, approving the concept but expressing reservations about the slogan.


Image above: After recovery by the crew of the USS Lake Champlain on Aug. 29, 1965, Gemini V pilot Charles "Pete" Conrad tweaks the eight-day growth of beard of command pilot Gordon Cooper. Image Credit: NASA.

"I have a very strong concern about the '8 days or bust' motto," he said in the Aug. 14, 1965, memo. "I wish it could be omitted. If the flight does not go eight days, there are many who are going to say it was 'busted.'"

Since the patches were already produced with the slogan, fabric was sewn over the motto on the patches worn by Cooper and Conrad during the flight.

"We're on our way," said Cooper as Gemini V lifted off from Cape Kennedy's Launch Pad 19 on Aug. 21, 1965.

The first major test was to practice tracking and catching up with the rendezvous pod. The 74-pound package was ejected from the adapter at the back of the spacecraft during the second orbit.


Image above: NASA astronaut Scott Kelly arrives aboard the International Space Station on March 28, 2015. Now, 50 years after Gemini V, Kelly and Russian cosmonaut Mikhail Kornienko are in the midst of a one-year stay in orbit. By doubling the length of the usual ISS stay, researchers hope to better understand how the human body reacts and adapts to longer-duration spaceflight. Image Credit: NASA.

"We got the REP out," said Conrad. "It's moving away at four feet a second on our radar."

The pod contained a radar transponder, flashing beacons, batteries and an antenna. The plan called for Gemini V to maneuver away from the instrument package, six miles below and 14 miles behind, and then rendezvous with the pod.

About half an hour after deploying the REP, fellow astronaut Jim McDivitt, serving as capsule communicator in mission control, asked the crew to check the fuel cell heaters to maintain proper pressure in the reactant tanks. The new electricity generators were not performing as expected.

"We have checked that," Cooper said. "I can't get an increase in amperage when I go to manual O2 (oxygen) fuel cell heater, nor do I get any reading in amperage when I go to auto. The H2 (hydrogen) heater works perfectly."

While out of radio contact with the ground, the crew found that the pressure in the fuel cells continued to drop.


Image above: East Central Florida is visible in this image taken during the Gemini V. Looking south, Cape Kennedy and the Kennedy Space Center in Florida are visible. The nose of the Gemini is in the lower left. Image Credits: NASA/Charles Conrad.

"We have decided to power down the radar and we're in the process of powering down the spacecraft," said Cooper when Gemini V passed over the next tracking station. "Our fuel cell oxygen pickup is still falling."

Tracking the REP was cancelled and consideration was given to bringing the crew back early. However, engineers at the McDonnell Aircraft facility in St. Louis conducted quickly arranged tests showing that it was possible for the fuel cells to work, even with low oxygen pressure.

With this reassurance, flight director Gene Kranz and his mission control team decided to tell Cooper and Conrad to turn the electricity back on. They were relieved when the fuel cells were restarted and tested by using equipment that required more and more power. This showed that the fuel cell pressure remained stable and the crew could continue its mission.

In the meantime, fellow astronaut Buzz Aldrin developed an alternative rendezvous test since the REP was no longer available. His astronautics doctoral thesis from the Massachusetts Institute of Technology was "Guidance for Manned Orbital Rendezvous." Aldrin worked out a plan in which the crew could rendezvous with a "point in space." It went perfectly, and marked the first-ever precision maneuvers on a spaceflight.

The Gemini V crew went to work on other experiments planned for the mission, including high-resolution photography, medical experiments similar to those performed on Gemini IV, as well as an experiment into the performance of the human heart in microgravity.

Launch of Gemini 5 (CBS audio)

Video above: Launch of Gemini 5 - August 21st 1965. Onboard are astronauts Gordon Cooper (Command Pilot) and Pete Conrad (Pilot). This is the CBS TV coverage (audio only) and NASA stock footage of this event remixed by "Lunarmodule". Video Credit: NASA/CBS.

Cooper and Conrad returned to Earth on Aug. 29, 1965. They controlled their re-entry, creating drag and lift by rotating the capsule. Even so, the crew splashed down in the Atlantic Ocean about 80 miles short of the planned landing point due to a computing error. A helicopter from the recovery ship, USS Lake Champlain, soon picked up the Gemini V crew and took them to the aircraft carrier.

The day after the splashdown, Cooper and Conrad returned to Kennedy for three days of medical checkups.

"It's good to be back here at the place where we spent our last weeks in training," said Cooper upon arrival.

NASA Deputy Administrator Hugh Dryden summed up the success of Gemini V in a Sept. 11, 1965 report to President Lyndon Johnson.

"The primary objective of the Gemini V mission was to demonstrate man's ability to function in the space environment for eight days and to qualify the spacecraft systems under these conditions," he said. "The adaptability of the human body was indicated by the performance of the astronauts. This has assured us of man's capability to travel to the moon and return."

Related link:

Gemini Program: http://www.nasa.gov/mission_pages/gemini/index.html

Images (mentioned), Video (mentioned), Text, Credits: NASA's Kennedy Space Center/Bob Granath.

Greetings, Orbiter.ch

From a Million Miles Away, NASA Camera Shows Moon Crossing Face of Earth









NASA - DSCOVR Mission logo.

Aug. 5, 2015

A NASA camera aboard the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the moon as it moved in front of the sunlit side of Earth last month. The series of test images shows the fully illuminated “dark side” of the moon that is never visible from Earth.

The images were captured by NASA’s Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope on the DSCOVR satellite orbiting 1 million miles from Earth. From its position between the sun and Earth, DSCOVR conducts its primary mission of real-time solar wind monitoring for the National Oceanic and Atmospheric Administration (NOAA).


This animation features actual satellite images of the far side of the moon, illuminated by the sun, as it crosses between the DSCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) and telescope, and the Earth - one million miles away. Animation Credits: NASA/NOAA.

EPIC maintains a constant view of the fully illuminated Earth as it rotates, providing scientific observations of ozone, vegetation, cloud height and aerosols in the atmosphere. Once EPIC begins regular observations next month, the camera will provide a series of Earth images allowing study of daily variations over the entire globe. About twice a year the camera will capture the moon and Earth together as the orbit of DSCOVR crosses the orbital plane of the moon.

These images were taken between 3:50 p.m. and 8:45 p.m. EDT on July 16, showing the moon moving over the Pacific Ocean near North America. The North Pole is in the upper left corner of the image, reflecting the orbital tilt of Earth from the vantage point of the spacecraft.

The far side of the moon was not seen until 1959 when the Soviet Luna 3 spacecraft returned the first images. Since then, several NASA missions have imaged the lunar far side in great detail. The same side of the moon always faces an earthbound observer because the moon is tidally locked to Earth. That means its orbital period is the same as its rotation around its axis.

In May 2008 NASA’s Deep Impact spacecraft captured a similar view of Earth and the moon from a distance of 31 million miles away. The series of images showed the moon passing in front of our home planet when it was only partially illuminated by the sun.


Image above: This image shows the far side of the moon, illuminated by the sun, as it crosses between the DSCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth - one million miles away. Image Credits: NASA/NOAA.

EPIC’s “natural color” images of Earth are generated by combining three separate monochrome exposures taken by the camera in quick succession. EPIC takes a series of 10 images using different narrowband spectral filters -- from ultraviolet to near infrared -- to produce a variety of science products. The red, green and blue channel images are used in these color images.

Combining three images taken about 30 seconds apart as the moon moves produces a slight but noticeable camera artifact on the right side of the moon. Because the moon has moved in relation to the Earth between the time the first (red) and last (green) exposures were made, a thin green offset appears on the right side of the moon when the three exposures are combined. This natural lunar movement also produces a slight red and blue offset on the left side of the moon in these unaltered images.

The lunar far side lacks the large, dark, basaltic plains, or maria, that are so prominent on the Earth-facing side. The largest far side features are Mare Moscoviense in the upper left and Tsiolkovskiy crater in the lower left. A thin sliver of shadowed area of moon is visible on its right side.

“It is surprising how much brighter Earth is than the moon," said Adam Szabo, DSCOVR project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. "Our planet is a truly brilliant object in dark space compared to the lunar surface.”

Deep Space Climate Observatory (DSCOVR) satellite. Image Credit: NASA

Once EPIC begins regular observations next month, NASA will post daily color images of Earth to a dedicated public website. These images, showing different views of the planet as it rotates through the day, will be available 12 to 36 hours after they are acquired.

DSCOVR is a partnership between NASA, NOAA and the U.S. Air Force with the primary objective of maintaining the nation’s real-time solar wind monitoring capabilities, which are critical to the accuracy and lead time of space weather alerts and forecasts from NOAA.

For more information about DSCOVR, visit: http://www.nesdis.noaa.gov/DSCOVR

Images (mentioned), Animation (mentioned), Text, Credits: NASA’s Goddard Space Flight Center/Rob Gutro/Karl Hille.

Best regards, Orbiter.ch

The Ghost of a Dying Star












ESO - European Southern Observatory logo.

5 August 2015

The planetary nebula ESO 378-1

This extraordinary bubble, glowing like the ghost of a star in the haunting darkness of space, may appear supernatural and mysterious, but it is a familiar astronomical object: a planetary nebula, the remnants of a dying star. This is the best view of the little-known object ESO 378-1 yet obtained and was captured by ESO's Very Large Telescope in northern Chile.

Nicknamed the Southern Owl Nebula, this shimmering orb is a planetary nebula with a diameter of almost four light-years. Its informal name relates to its visual cousin in the northern hemisphere, the Owl Nebula. ESO 378-1 [1], which is also catalogued as PN K 1-22 and PN G283.6+25.3, is located in the constellation of Hydra (The Female Water Snake).

The location of the planetary nebula ESO 378-1

Like all planetary nebulae, ESO 378-1 is a relatively short-lived phenomenon, lasting only a few tens of thousands of years, compared to a typical stellar lifetime of several billion years [2].

Planetary nebulae are created by the ejected and expanding gas of dying stars. Although they are brilliant and intriguing objects in the initial stages of formation, these bubbles fade away as their constituent gas moves away and the central stars grow dimmer.

For a planetary nebula to form, the aging star must have a mass less than about eight times that of the Sun. Stars that are heavier than this limit will end their lives in dramatic fashion as supernova explosions.

The sky around the location of the planetary nebula ESO 378-1

As these less massive stars grow old they start to lose their outer layers of gas to stellar winds. After most of these outer layers have dissipated, the remaining hot stellar core starts to emit ultraviolet radiation which then ionises the surrounding gas. This ionisation causes the expanding shell of ghostly gas to begin to glow in bright colours.

After the planetary nebula has faded away, the leftover stellar remnant will burn for another billion years before consuming all its remaining fuel. It will then become a tiny — but hot and very dense — white dwarf that will slowly cool over billions of years. The Sun will produce a planetary nebula several billion years in the future and will afterwards also spend its twilight years as a white dwarf.

Zooming in on the planetary nebula ESO 378-1

Planetary nebulae play a crucial role in the chemical enrichment and evolution of the Universe. Elements such as carbon and nitrogen, as well as some other heavier elements, are created in these stars and returned to the interstellar medium. Out of this material new stars, planets and eventually life can form. Hence astronomer Carl Sagan's famous phrase: "We are made of star stuff."

This picture comes from the ESO Cosmic Gems programme, an outreach 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.

Panning across the planetary nebula ESO 378-1

Notes:

[1] The ESO in the name of this object refers to a catalogue of objects compiled in the 1970s and 80s from careful inspection of new photographs taken with the ESO 1-metre Schmidt telescope at La Silla.

[2] The lifetime of a planetary nebula as a fraction of a star's life is about the same as the life of a soap bubble compared to the age of the child who blows it.

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 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. 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 a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become "the world’s biggest eye on the sky".

Links

ESO Cosmic Gems programme: http://www.eso.org/public/outreach/gems.html

Photos of the Very Large Telescope: http://www.eso.org/public/images/archive/search/?adv=&subject_name=Very%20Large%20Telescope

Photos from the Very Large Telescope: http://www.eso.org/public/images/archive/search/?adv=&facility=31

Related links:

ESO Cosmic Gems programme: http://www.eso.org/public/outreach/gems.html

ESO 1-metre Schmidt telescope at La Silla: http://www.eso.org/public/teles-instr/lasilla/1mschmidt/

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

Greetings, Orbiter.ch

mardi 4 août 2015

NASA Sees Soudelor Reach Category 5 Typhoon Status
















NASA - Aqua Mission logo / NASA - ISS-RapidScat logo.

Aug. 4, 2015

Soudelor (Northwestern Pacific Ocean)

NASA's Aqua satellite and RapidScat instrument analyzed Super typhoon Soudelor's extent and winds as it reached Category Five typhoon status on the Saffir-Simpson Wind Scale.


Image above: On Aug. 4, 2015, at 4:10 UTC (12:10 a.m. EDT) the MODIS instrument aboard NASA's Aqua satellite captured this visible-light image of Super typhoon Soudelor. Image Credits: NASA Goddard's MODIS Rapid Response Team.

RapidScat is a NASA instrument that flies aboard the International Space Station. RapidScat gathered surface wind speed and direction data on Soudelor on Aug. 3 at 1900 UTC (3 p.m. EDT) when it just west of Mariana Islands. RapidScat measured saw the strongest sustained winds circled the center. Sustained winds at that time were near 135 knots (155 mph/250 kph).

On Aug. 4 at 4:10 UTC (12:10 a.m. EDT) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite captured a visible-light image of Super typhoon Soudelor that clearly showed its 12-nautical-mile-wide eye. Thick bands of powerful thunderstorms surrounded the storm and spiraled into the center.


Image above: RapidScat gathered wind speed and direction data on Soudelor on Aug. 3, 2015, at 1900 UTC (3 p.m. EDT) just west of Mariana Islands. RapidScat measure sustained winds around the center at more than 36 meters per second/70 knots/80.5 mph/129.6 kph). Image Credits: NASA JPL, Doug Tyler.

At 0900 (5 a.m. EDT), Super typhoon Soudelor had maximum sustained winds near 140 knots (161.1 mph/ 259.3 kph). Those typhoon-force winds stretched out up to 40 miles from the center, while tropical-storm-force winds extended 185 miles from the center. The Joint Typhoon Warning Center expects the storm to maintain that intensity for another 24 hours.

ISS-RapidScat in action. Animation Credit: NASA

Soudelor was located near 18.6 North latitude and 138.8. East longitude, about 750 nautical miles (863 miles/1,389 km) from Kadena Air Base, Okinawa, Japan. Soudelor was moving to the west-northwest at 13 knots (14.9 mph/24.0 kph).

This super typhoon was generating extremely rough seas, with maximum significant wave height to 48 feet (14.6 meters)!

The Joint Typhoon Warning Center forecast takes Soudelor on a west-northwesterly path near the Japanese island of Ishigakijima on August 7 and then over northern Taiwan before making landfall in southeastern China on August 8.

Artist's view of Aqua satellite. Image Credit: NASA

The storm is predicted to weaken as it continues on its trek to the west-northwest. Interests in the path of this Super typhoon should prepare for storm surge, heavy rainfall, mudslides in high terrain areas, and typhoon-force winds.

For forecast warnings from the Japan Meteorological Agency, visit:  http://www.jma.go.jp/jma/indexe.html. For warnings and watches for Taiwan, visit the Central Weather Bureau website: http://www.cwb.gov.tw/eng/. For warnings in China, visit the China Meteorological Administration website: http://www.cma.gov.cn/en.

For more information about ISS-RapidScat, visit: http://www.nasa.gov/mission_pages/station/research/experiments/1067.html

For more information about Aqua satellite mission, visit: http://aqua.nasa.gov/

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

Greetings, Orbiter.ch