Huge Cavity in Antarctic Glacier Signals Rapid Decay

NASA - Operation IceBridge Mission patch.

January 30, 2019

A gigantic cavity - two-thirds the area of Manhattan and almost 1,000 feet (300 meters) tall - growing at the bottom of Thwaites Glacier in West Antarctica is one of several disturbing discoveries reported in a new NASA-led study of the disintegrating glacier. The findings highlight the need for detailed observations of Antarctic glaciers' undersides in calculating how fast global sea levels will rise in response to climate change.

Researchers expected to find some gaps between ice and bedrock at Thwaites' bottom where ocean water could flow in and melt the glacier from below. The size and explosive growth rate of the newfound hole, however, surprised them. It's big enough to have contained 14 billion tons of ice, and most of that ice melted over the last three years.

Thwaites Glacier. Image Credit: NASA/OIB/Jeremy Harbeck

"We have suspected for years that Thwaites was not tightly attached to the bedrock beneath it," said Eric Rignot of the University of California, Irvine, and NASA's Jet Propulsion Laboratory in Pasadena, California. Rignot is a co-author of the new study, which was published today in Science Advances. "Thanks to a new generation of satellites, we can finally see the detail," he said.

The cavity was revealed by ice-penetrating radar in NASA's Operation IceBridge, an airborne campaign beginning in 2010 that studies connections between the polar regions and the global climate. The researchers also used data from a constellation of Italian and German spaceborne synthetic aperture radars. These very high-resolution data can be processed by a technique called radar interferometry to reveal how the ground surface below has moved between images.

"[The size of] a cavity under a glacier plays an important role in melting," said the study's lead author, Pietro Milillo of JPL. "As more heat and water get under the glacier, it melts faster."

Numerical models of ice sheets use a fixed shape to represent a cavity under the ice, rather than allowing the cavity to change and grow. The new discovery implies that this limitation most likely causes those models to underestimate how fast Thwaites is losing ice.

About the size of Florida, Thwaites Glacier is currently responsible for approximately 4 percent of global sea level rise. It holds enough ice to raise the world ocean a little over 2 feet (65 centimeters) and backstops neighboring glaciers that would raise sea levels an additional 8 feet (2.4 meters) if all the ice were lost.

Animation above: Changes in surface height at Thwaites Glacier's grounding line, 2011 to 2017, with sinking areas in red and rising areas in blue. The growing cavity (red mass, center) caused the greatest sinking. The mottled area (bottom left) is the site of extensive calving. Contours show bedrock topography. Animation Credits: NASA/JPL-Caltech.

Thwaites is one of the hardest places to reach on Earth, but it is about to become better known than ever before. The U.S. National Science Foundation and British National Environmental Research Council are mounting a five-year field project to answer the most critical questions about its processes and features. The International Thwaites Glacier Collaboration will begin its field experiments in the Southern Hemisphere summer of 2019-20.

How Scientists Measure Ice Loss

There's no way to monitor Antarctic glaciers from ground level over the long term. Instead, scientists use satellite or airborne instrument data to observe features that change as a glacier melts, such as its flow speed and surface height.

Another changing feature is a glacier's grounding line - the place near the edge of the continent where it lifts off its bed and starts to float on seawater. Many Antarctic glaciers extend for miles beyond their grounding lines, floating out over the open ocean.

Just as a grounded boat can float again when the weight of its cargo is removed, a glacier that loses ice weight can float over land where it used to stick. When this happens, the grounding line retreats inland. That exposes more of a glacier's underside to sea water, increasing the likelihood its melt rate will accelerate.

An Irregular Retreat

For Thwaites, "We are discovering different mechanisms of retreat," Millilo said. Different processes at various parts of the 100-mile-long (160-kilometer-long) front of the glacier are putting the rates of grounding-line retreat and of ice loss out of sync.

The huge cavity is under the main trunk of the glacier on its western side - the side farther from the West Antarctic Peninsula. In this region, as the tide rises and falls, the grounding line retreats and advances across a zone of about 2 to 3 miles (3 to 5 kilometers). The glacier has been coming unstuck from a ridge in the bedrock at a steady rate of about 0.4 to 0.5 miles (0.6 to 0.8 kilometers) a year since 1992. Despite this stable rate of grounding-line retreat, the melt rate on this side of the glacier is extremely high.

"On the eastern side of the glacier, the grounding-line retreat proceeds through small channels, maybe a kilometer wide, like fingers reaching beneath the glacier to melt it from below," Milillo said. In that region, the rate of grounding-line retreat doubled from about 0.4 miles (0.6 kilometers) a year from 1992 to 2011 to 0.8 miles (1.2 kilometers) a year from 2011 to 2017. Even with this accelerating retreat, however, melt rates on this side of the glacier are lower than on the western side.

These results highlight that ice-ocean interactions are more complex than previously understood.

Milillo hopes the new results will be useful for the International Thwaites Glacier Collaboration researchers as they prepare for their fieldwork. "Such data is essential for field parties to focus on areas where the action is, because the grounding line is retreating rapidly with complex spatial patterns," he said.

"Understanding the details of how the ocean melts away this glacier is essential to project its impact on sea level rise in the coming decades," Rignot said.

The paper by Milillo and his co-authors in the journal Science Advances is titled "Heterogeneous retreat and ice melt of Thwaites Glacier, West Antarctica." Co-authors were from the University of California, Irvine; the German Aerospace Center in Munich, Germany; and the University Grenoble Alpes in Grenoble, France.

Related links:

Operation IceBridge: https://www.nasa.gov/mission_pages/icebridge/index.html

International Thwaites Glacier Collaboration: https://thwaitesglacier.org/

Image (mentioned), Animation (mentioned), Text, Credits: NASA/JPL/Esprit Smith/University of California/Brian Bell/NASA's Earth Science News Team, written by Carol Rasmussen.

Greetings, Orbiter.ch

NASA’s NICER Mission Maps ‘Light Echoes’ of New Black Hole

NASA - Neutron star Interior Composition Explorer (NICER) patch.

Jan. 30, 2019

Scientists have charted the environment surrounding a stellar-mass black hole that is 10 times the mass of the Sun using NASA’s Neutron star Interior Composition Explorer (NICER) payload aboard the International Space Station. NICER detected X-ray light from the recently discovered black hole, called MAXI J1820+070 (J1820 for short), as it consumed material from a companion star. Waves of X-rays formed “light echoes” that reflected off the swirling gas near the black hole and revealed changes in the environment’s size and shape.

“NICER has allowed us to measure light echoes closer to a stellar-mass black hole than ever before,” said Erin Kara, an astrophysicist at the University of Maryland, College Park and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who presented the findings at the 233rd American Astronomical Society meeting in Seattle. “Previously, these light echoes off the inner accretion disk were only seen in supermassive black holes, which are millions to billions of solar masses and undergo changes slowly. Stellar black holes like J1820 have much lower masses and evolve much faster, so we can see changes play out on human time scales.”

A paper describing the findings, led by Kara, appeared in the Jan. 10 issue of Nature and is available online: http://dx.doi.org/10.1038/s41586-018-0803-x

NICER Charts the Area Around a New Black Hole

Video above: Watch how X-ray echoes, mapped by NASA’s Neutron star Interior Composition Explorer (NICER) revealed changes to the corona of black hole MAXI J1820+070. Video Credits: NASA’s Goddard Space Flight Center.

J1820 is located about 10,000 light-years away toward the constellation Leo. The companion star in the system was identified in a survey by ESA’s (European Space Agency) Gaia mission, which allowed researchers to estimate its distance. Astronomers were unaware of the black hole’s presence until March 11, 2018, when an outburst was spotted by the Japan Aerospace Exploration Agency’s Monitor of All-sky X-ray Image (MAXI), also aboard the space station. J1820 went from a totally unknown black hole to one of the brightest sources in the X-ray sky over a few days. NICER moved quickly to capture this dramatic transition and continues to follow the fading tail of the eruption.

“NICER was designed to be sensitive enough to study faint, incredibly dense objects called neutron stars,” said Zaven Arzoumanian, the NICER science lead at Goddard and a co-author of the paper. “We’re pleased at how useful it’s also proven in studying these very X-ray-bright stellar-mass black holes.”

A black hole can siphon gas from a nearby companion star into a ring of material called an accretion disk. Gravitational and magnetic forces heat the disk to millions of degrees, making it hot enough to produce X-rays at the inner parts of the disk, near the black hole. Outbursts occur when an instability in the disk causes a flood of gas to move inward, toward the black hole, like an avalanche. The causes of disk instabilities are poorly understood.

Above the disk is the corona, a region of subatomic particles around 1 billion degrees Celsius (1.8 billion degrees Fahrenheit) that glows in higher-energy X-rays. Many mysteries remain about the origin and evolution of the corona. Some theories suggest the structure could represent an early form of the high-speed particle jets these types of systems often emit.

Image above: In this illustration of a newly discovered black hole named MAXI J1820+070, a black hole pulls material off a neighboring star and into an accretion disk. Above the disk is a region of subatomic particles called the corona. Image Credits: Aurore Simonnet and NASA’s Goddard Space Flight Center.

Astrophysicists want to better understand how the inner edge of the accretion disk and the corona above it change in size and shape as a black hole accretes material from its companion star. If they can understand how and why these changes occur in stellar-mass black holes over a period of weeks, scientists could shed light on how supermassive black holes evolve over millions of years and how they affect the galaxies in which they reside.

One method used to chart those changes is called X-ray reverberation mapping, which uses X-ray reflections in much the same way sonar uses sound waves to map undersea terrain. Some X-rays from the corona travel straight toward us, while others light up the disk and reflect back at different energies and angles.

X-ray reverberation mapping of supermassive black holes has shown that the inner edge of the accretion disk is very close to the event horizon, the point of no return. The corona is also compact, lying closer to the black hole rather than over much of the accretion disk. Previous observations of X-ray echoes from stellar black holes, however, suggested the inner edge of the accretion disk could be quite distant, up to hundreds of times the size of the event horizon. The stellar-mass J1820, however, behaved more like its supermassive cousins. 

As they examined NICER’s observations of J1820, Kara’s team saw a decrease in the delay, or lag time, between the initial flare of X-rays coming directly from the corona and the flare’s echo off the disk, indicating that the X-rays traveled shorter and shorter distances before they were reflected. From 10,000 light-years away, they estimated that the corona contracted vertically from roughly 100 to 10 miles — that’s like seeing something the size of a blueberry shrink to something the size of a poppy seed at the distance of Pluto

Neutron star Interior Composition Explorer (NICER). Animation Credit: NASA

“This is the first time that we’ve seen this kind of evidence that it’s the corona shrinking during this particular phase of outburst evolution,” said co-author Jack Steiner, an astrophysicist at the Massachusetts Institute of Technology’s Kavli Institute for Astrophysics and Space Research in Cambridge. “The corona is still pretty mysterious, and we still have a loose understanding of what it is. But we now have evidence that the thing that’s evolving in the system is the structure of the corona itself.”

To confirm the decreased lag time was due to a change in the corona and not the disk, the researchers used a signal called the iron K line created when X-rays from the corona collide with iron atoms in the disk, causing them to fluoresce. Time runs slower in stronger gravitational fields and at higher velocities, as stated in Einstein’s theory of relativity. When the iron atoms closest to the black hole are bombarded by light from the core of the corona, the X-ray wavelengths they emit get stretched because time is moving slower for them than for the observer (in this case, NICER).

Kara’s team discovered that J1820’s stretched iron K line remained constant, which means the inner edge of the disk remained close to the black hole — similar to a supermassive black hole. If the decreased lag time was caused by the inner edge of the disk moving even further inward, then the iron K line would have stretched even more.

These observations give scientists new insights into how material funnels in to the black hole and how energy is released in this process.

Image above: The NICER instrument installed on the International Space Station, as captured by a high-definition external camera on Oct. 22, 2018. Image Credit: NASA.

“NICER’s observations of J1820 have taught us something new about stellar-mass black holes and about how we might use them as analogs for studying supermassive black holes and their effects on galaxy formation,” said co-author Philip Uttley, an astrophysicist at the University of Amsterdam. “We’ve seen four similar events in NICER’s first year, and it’s remarkable. It feels like we’re on the edge of a huge breakthrough in X-ray astronomy.”

NICER is an Astrophysics Mission of Opportunity within NASA's Explorer program, which provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches within the heliophysics and astrophysics science areas. NASA's Space Technology Mission Directorate supports the SEXTANT component of the mission, demonstrating pulsar-based spacecraft navigation.

Related links:

NASA’s Neutron star Interior Composition Explorer (NICER): https://www.nasa.gov/nicer

Monitor of All-sky X-ray Image (MAXI): https://www.nasa.gov/mission_pages/station/research/experiments/603.html

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

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

NASA’s Goddard Space Flight Center (GSFC): https://www.nasa.gov/goddard

University of Maryland: https://www.umd.edu/

European Space Agency (ESA): https://www.esa.int/ESA

Japan Aerospace Exploration Agency (JAXA): http://global.jaxa.jp/

Images (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, by Jeanette Kazmierczak.

Greetings, Orbiter.ch

Station Crew Helping Future Orion Explorers

ISS - Expedition 58 Mission patch.

January 29, 2019

The International Space Station is providing a research platform today to help future astronauts navigate deep space in the Orion Multi-Purpose Crew Vehicle. The Expedition 58 crew is also testing new lights and setting up the orbital lab for CubeSat deployments.

NASA is planning deep space missions with its new Orion spacecraft that will rely on NASA’s Deep Space Network for communications and navigation. Flight Engineer David Saint-Jacques took photographs of the moon from the cupola today to calibrate Orion’s navigation software. The lunar data will provide additional navigation capability for Orion in the event of a loss of communication with the Deep Space Network.

Image above: The International Space Station photographed by departing Expedition 56 crew members aboard a Soyuz spacecraft after undocking on Oct. 4, 2018. Image Credit: NASA.

Another experiment geared towards future exploration taking place aboard the station is the Sextant study. As its name suggests, astronauts are testing a hand-held sextant to focus on stability and star-sighting opportunities while in microgravity. Results may aid future Orion explorers and provide a backup navigation source for missions far beyond Earth orbit.

Astronaut Anne McClain worked throughout the day inside Japan’s Kibo laboratory module. She is setting up the Kibo airlock with hardware to deploy a set of CubeSats on Thursday. The CubeSats have a variety of educational and technical mission objectives including studying the ionosphere and satellite communications.

Flying over auroras. Animation Credit: NASA

McClain later tested and photographed new lights that scientists are researching for their ability to improve crew sleep and performance. She also continued loading the Northrop Grumman Cygnus cargo craft with disposable gear before it departs from the Unity module Feb. 8.

Both McClain and Saint-Jacques joined Commander Oleg Kononenko early Tuesday for body mass measurements. Kononenko then moved on to life support maintenance, crew culture studies and radiation measurements aboard the orbital lab.

Related links:

Expedition 58: https://www.nasa.gov/mission_pages/station/expeditions/expedition58/index.html

Orion spacecraft: https://www.nasa.gov/exploration/systems/orion/index.html

Deep Space Network: https://deepspace.jpl.nasa.gov/

Cupola: https://www.nasa.gov/mission_pages/station/structure/elements/cupola.html

Sextant: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7646

Kibo laboratory module: https://www.nasa.gov/mission_pages/station/structure/elements/japan-kibo-laboratory

CubeSats: https://www.nasa.gov/mission_pages/cubesats/index.html

Unity module: https://www.nasa.gov/mission_pages/station/structure/elements/unity

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

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

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

Warming Seas May Increase Frequency of Extreme Storms

NASA - EOS Aqua Mission logo.

Jan. 29, 2019

A new NASA study shows that warming of the tropical oceans due to climate change could lead to a substantial increase in the frequency of extreme rain storms by the end of the century.

Image above: An "anvil" storm cloud in the Midwestern U.S. Image Credit: UCAR.

The study team, led by Hartmut Aumann of NASA's Jet Propulsion Laboratory in Pasadena, California, combed through 15 years of data acquired by NASA's Atmospheric Infrared Sounder (AIRS) instrument over the tropical oceans to determine the relationship between the average sea surface temperature and the onset of severe storms.

They found that extreme storms — those producing at least 0.12 inches (3 millimeters) of rain per hour over a 16-mile (25-kilometer) area — formed when the sea surface temperature was higher than about 82 degrees Fahrenheit (28 degrees Celsius). They also found that, based on the data, 21 percent more storms form for every 1.8 degrees Fahrenheit (1 degree Celsius) that ocean surface temperatures rise.

"It is somewhat common sense that severe storms will increase in a warmer environment. Thunderstorms typically occur in the warmest season of the year," Aumann explained. "But our data provide the first quantitative estimate of how much they are likely to increase, at least for the tropical oceans."

Image above: A hurricane as seen by NASA's Atmospheric Infrared Sounder (AIRS) instrument. A hurricane is a large collection of extremely severe thunderstorms — seen here in dark blue. Each square pixel represents the measurements from a 10-by-10-mile (16-by-16-kilometer) area. At the time this image was taken, there were 140 of these extreme thunderstorms rotating about the eye of the hurricane. Image Credits: NASA/JPL-Caltech.

Currently accepted climate models project that with a steady increase of carbon dioxide in the atmosphere (1 percent per year), tropical ocean surface temperatures may rise by as much as 4.8 degrees Fahrenheit (2.7 degrees Celsius) by the end of the century. The study team concludes that if this were to happen, we could expect the frequency of extreme storms to increase by as much as 60 percent by that time.

EOS Aqua satellite. Image Credit: NASA

Although climate models aren't perfect, results like these can serve as a guideline for those looking to prepare for the potential effects a changing climate may have.

"Our results quantify and give a more visual meaning to the consequences of the predicted warming of the oceans," Aumann said. "More storms mean more flooding, more structure damage, more crop damage and so on, unless mitigating measures are implemented."

The peer-reviewed study was published in the December 2018 issue of the Geophysical Research Letters journal.

Aqua Satellite: https://www.nasa.gov/mission_pages/aqua/index.html

Climate: https://www.nasa.gov/subject/3127/climate

Images (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Esprit Smith.

Greetings, Orbiter.ch

New Horizons' Newest and Best-Yet View of Ultima Thule

NASA - New Horizons Mission patch.

January 29, 2019

Image above: Best-Yet View of Ultima Thule. Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

The wonders – and mysteries – of Kuiper Belt object 2014 MU69 continue to multiply as NASA's New Horizons spacecraft beams home new images of its New Year's Day 2019 flyby target.

This image, taken during the historic Jan. 1 flyby of what's informally known as Ultima Thule, is the clearest view yet of this remarkable, ancient object in the far reaches of the solar system – and the first small "KBO" ever explored by a spacecraft.

Obtained with the wide-angle Multicolor Visible Imaging Camera (MVIC) component of New Horizons' Ralph instrument, this image was taken when the KBO was 4,200 miles (6,700 kilometers) from the spacecraft, at 05:26 UT (12:26 a.m. EST) on Jan. 1 – just seven minutes before closest approach. With an original resolution of 440 feet (135 meters) per pixel, the image was stored in the spacecraft's data memory and transmitted to Earth on Jan. 18-19. Scientists then sharpened the image to enhance fine detail. (This process – known as deconvolution – also amplifies the graininess of the image when viewed at high contrast.)

The oblique lighting of this image reveals new topographic details along the day/night boundary, or terminator, near the top. These details include numerous small pits up to about 0.4 miles (0.7 kilometers) in diameter. The large circular feature, about 4 miles (7 kilometers) across, on the smaller of the two lobes, also appears to be a deep depression. Not clear is whether these pits are impact craters or features resulting from other processes, such as "collapse pits" or the ancient venting of volatile materials.

Image above: Illustration of NASA’s New Horizons spacecraft encountering 2014 MU69 – nicknamed “Ultima Thule” – a Kuiper Belt object that orbits one billion miles beyond Pluto. New Horizons’ exploration of Ultima is the farthest space probe flyby in history. Image Credits: NASA/JHUAPL/SwRI.

Both lobes also show many intriguing light and dark patterns of unknown origin, which may reveal clues about how this body was assembled during the formation of the solar system 4.5 billion years ago. One of the most striking of these is the bright "collar" separating the two lobes.

"This new image is starting to reveal differences in the geologic character of the two lobes of Ultima Thule, and is presenting us with new mysteries as well," said Principal Investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado. "Over the next month there will be better color and better resolution images that we hope will help unravel the many mysteries of Ultima Thule."

New Horizons is approximately 4.13 billion miles (6.64 billion kilometers) from Earth, operating normally and speeding away from the Sun (and Ultima Thule) at more than 31,500 miles (50,700 kilometers) per hour. At that distance, a radio signal reaches Earth six hours and nine minutes after leaving the spacecraft.

Related article:

New Movie Shows Ultima Thule from an Approaching New Horizons
https://orbiterchspacenews.blogspot.com/2019/01/new-movie-shows-ultima-thule-from.html

New Horizons LORRI website: http://pluto.jhuapl.edu/soc/UltimaThule-Encounter/

For more information on the New Horizons mission, visit: https://www.nasa.gov/newhorizons

Images (mentioned), Text, Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Greetings, Orbiter.ch

Crew Tests Time Perception in Space and Real-Time Vital Signs Monitoring

ISS - Expedition 58 Mission patch.

January 28, 2019

The Expedition 58 astronauts explored time perception and tested a wearable body monitor aboard the International Space Station today. The orbital residents also packed a U.S. space freighter and set up tiny satellites controlled by students on Earth.

Image above: NASA astronaut Anne McClain is pictured exercising aboard the International Space Station inside the U.S. Destiny laboratory module. Image Credit: NASA.

Astronauts Anne McClain and David Saint-Jacques started Monday in the Columbus lab module learning how microgravity affects time perception. During the experiment the crew judges time length with results compared to ground tests. Scientists hypothesize that astronauts experience time passing at a faster rate than those of us here on Earth.

McClain then spent the rest of the day with Commander Oleg Kononenko setting up and monitoring SPHERES satellites in the Kibo lab module. High school students compete to design the best algorithms that control the basketball-sized satellites to mimic spacecraft maneuvers and formation flying.

International Space Station (ISS). Animation Credit: NASA

Saint-Jacques set up a wearable device called the Bio-Monitor to test its ability to measure vital signs with minimum interference during a normal day in space. The Canadian astronaut also continued packing the Cygnus cargo craft from Northrop Grumman ahead of its Feb. 8 departure from the Unity module.

Related links:

Expedition 58: https://www.nasa.gov/mission_pages/station/expeditions/expedition58/index.html

Columbus lab module: https://www.nasa.gov/mission_pages/station/structure/elements/europe-columbus-laboratory

Time perception: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7504

SPHERES: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=679

Kibo lab module: https://www.nasa.gov/mission_pages/station/structure/elements/japan-kibo-laboratory

Bio-Monitor: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7392

Cygnus cargo craft: https://www.nasa.gov/feature/northrop-grumman-cygnus-launches-arrivals-and-departures

Unity module: https://www.nasa.gov/mission_pages/station/structure/elements/unity

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

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

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

All Systems Go As Parker Solar Probe Begins Second Sun Orbit

NASA - Parker Solar Probe Mission patch.

January 28, 2019

On Jan. 19, 2019, just 161 days after its launch from Cape Canaveral Air Force Station in Florida, NASA’s Parker Solar Probe completed its first orbit of the Sun, reaching the point in its orbit farthest from our star, called aphelion. The spacecraft has now begun the second of 24 planned orbits, on track for its second perihelion, or closest approach to the Sun, on April 4, 2019.

Parker Solar Probe closest approach to the Sun. Animation Credits: NASA/JHUAPL

Parker Solar Probe entered full operational status (known as Phase E) on Jan. 1, with all systems online and operating as designed. The spacecraft has been delivering data from its instruments to Earth via the Deep Space Network, and to date more than 17 gigabits of science data has been downloaded. The full dataset from the first orbit will be downloaded by April.

“It’s been an illuminating and fascinating first orbit,” said Parker Solar Probe Project Manager Andy Driesman, of the Johns Hopkins University Applied Physics Laboratory. “We’ve learned a lot about how the spacecraft operates and reacts to the solar environment, and I’m proud to say the team’s projections have been very accurate.” APL designed, built, and manages the mission for NASA.

“We’ve always said that we don’t know what to expect until we look at the data,” said Project Scientist Nour Raouafi, also of APL. “The data we have received hints at many new things that we’ve not seen before and at potential new discoveries. Parker Solar Probe is delivering on the mission’s promise of revealing the mysteries of our Sun.”

Image above: Parker Solar Probe’s position, speed and round-trip light time as of Jan. 28, 2019. Track the spacecraft online: http://parkersolarprobe.jhuapl.edu/The-Mission/index.php#Where-Is-PSP

The Parker Solar Probe team is not only focused on analyzing the science data but also preparing for the second solar encounter, which will take place in about two months.

In preparation for that next encounter, the spacecraft’s solid state recorder is being emptied of files that have already been delivered to Earth. In addition, the spacecraft is receiving updated positional and navigation information (called ephemeris) and is being loaded with a new automated command sequence, which contains about one month’s worth of instructions.

Like the mission’s first perihelion in November 2018, Parker Solar Probe’s second perihelion in April will bring the spacecraft to a distance of about 15 million miles from the Sun – just over half the previous close solar approach record of about 27 million miles set by Helios 2 in 1976.

The spacecraft’s four instrument suites will help scientists begin to answer outstanding questions about the Sun’s fundamental physics — including how particles and solar material are accelerated out into space at such high speeds and why the Sun’s atmosphere, the corona, is so much hotter than the surface below.

Parker Solar Probe: https://www.nasa.gov/content/goddard/parker-solar-probe

Animation (mentioned), Image (mentioned), Text, Credits: Johns Hopkins University Applied Physics Lab, by Geoff Brown.

Greetings, Orbiter.ch