NASA Glenn experiments shedding new light on Venus’ shrouded surface

NASA Glenn experiments shedding new light on Venus’ shrouded surface:

The planet Venus is permanently shrouded by cloud cover. Photo Credit NASA

CLEVELAND, Ohio — A special NASA test chamber apparatus is helping scientists explore the mysteries of Venus right here on Earth. The chamber is located at NASA’s Glenn Research Center in Cleveland, Ohio. It is hoped that this new vessel will help prepare the space agency for missions to extreme worlds.

GEER, the Glenn Extreme Environment Rig, is a high-tech pressure vessel capable of simulating the pressure, temperature, and atmospheric gas mix of Venus, or any other extreme planetary environment, for an extended period. Engineers at the NASA Glenn Research Center where GEER is housed, as well as scientists from nearby Case Western Reserve University, recently conducted a long-duration experiment in GEER that could yield important new information about the Venus environment.

A computer generated global view of Venus, centered at 180° East longitude, based on the Magellan probe’s radar mapping. (Click to enlarge) Image Credit: NASA/JPL

The recent test, completed in mid-July, lasted for some 80 days; it served as the follow-up to a 40-day test that was conducted in GEER about two years ago.

“This is more about planetary science than spaceflight,” Ralph Harvey, a Professor in the department of Earth Environment and Planetary Science at Case Western Reserve University, told Spaceflight Insider. “We decided GEER gives us the opportunity to do a large volume experiment […] and that we would simulate the most reactive situation I could think of between the crust of Venus and the atmosphere. And that situation is when new rock is exposed – when volcanoes spit out a bit of lava.”

Surface radar images of Venus and the resulting topographic maps show an abundance of volcanoes and lava flows on the planet’s surface. Harvey and his graduate student Brandon Radoman-Shaw, in cooperation with researchers and engineers at NASA Glenn, conceived of an experiment in which they took a suite of minerals that represent the key minerals in basaltic volcanic rocks – pyroxene, olivine, feldspars, and others – as well as some glasses, and placed them inside the GEER chamber. There, the minerals were exposed to a high-fidelity simulation of Venus’ surface conditions – not only of the physical conditions but also of the atmospheric composition as well.

“The GEER chamber is an unparalleled thing,” Harvey said. “Other people have done experiments simulating the Venus surface, but they were always limited in terms of their own technology. Often the vessel in which they simulated the Venus surface conditions was the size of a soda can or a thermos bottle. Or their experiments had been limited in terms of the temperatures or pressures they could reach.”

The GEER chamber is much larger than a soda can. It is cylindrical in shape, 3-feet (91 cm) in diameter by 4-feet (122 cm) long. The complex apparatus surrounding the pressure vessel allows researchers to carefully create and monitor the simulated pressure, temperature, and gas mix conditions at Venus’ surface.

“It is the surface and the near surface where we know the least about Venus,” Harvey said. “Yet it has clearly played a major role in how the planet has evolved. If the rock is all reacted and weathered there at the surface, that would be really important to know about as you are designing instruments and analytical techniques to study that.”

The recent 80-day experiment, as well as the previous 40-day experiment, is designed to help understand how the Venus atmosphere and fresh rock might interact. The most recent experiment is still under fresh analysis, but some upcoming research abstracts suggest some of the early implications of the experiments.

Harvey said: “What we are learning so far is that, in spite of the fact that CO₂ is the greenhouse gas that everyone pays a lot of attention to, it is probably sulfur that is the real mover and shaker. We don’t see a lot of activity of carbon. In fact, it doesn’t look like CO₂-bearing or carbonate minerals are very stable at all. It looks like they go away rather than form.”

The effect of CO₂ on Venus has long been a topic of debate among scientists, given immediacy by the greenhouse effects of CO₂ and its possible connections to climate change on Earth. The lack of new data from Venus on the subject has kept the debate alive for decades. The new data from the recent GEER experiment may add a new and unforeseen twist to the debate.

“Sulfur looks like a much bigger player than CO₂,” Harvey said. “Even though the atmosphere is mostly CO₂ and that’s the big greenhouse gas you read about in all the papers, sulfur is a much more active greenhouse gas, and it forms a really nasty, very reactive acid. Even though sulfur is a minor component of that atmosphere, it is a major player in how rocks on Venus interact with the atmosphere.”

The analysis of the 80-day experiment is just beginning. It will be some time before its findings are included in papers for publication. Nevertheless, Harvey already believes the experiment is likely to provide a new perspective from which to approach future studies of the Venus surface environment.

“In some ways, we’re kind of wiping the slate clean,” he said. “We’re going to figure out what reactions are more important and which ones are less important. We’re not going to be super quantitative or come up with reaction rates or describe the history of Venus hour by hour for the next billion years. However, on the other hand, it creates a new starting point for more sophisticated modeling and more experiments.”

LEFT: Kyle Phillips, NASA Glenn engineer, removes samples from GEER after they were exposed to Venus surface conditions for 80 days. RIGHT: Professor Ralph Harvey and graduate student Brandon Radoman-Shaw of Case Western Reserve University inspect mineral samples used in the 80-day simulated Venus surface environment test in the GEER chamber at NASA Glenn Research Center in Cleveland, Ohio. Photos Credit: NASA

The recent 80-day experiment would not have been possible without some significant redesigns to the systems of GEER. Simulating the 863 °F (462 °C) temperatures and the extreme atmospheric pressure 90 times that of Earth that exists at Venus’ surface is a challenge to materials and engineering.

“We pretty much redesigned our entire process system, and that is everything but the GEER vessel itself,” Leah Nakely, Chemical Test Engineer and Lead Engineer for the GEER Project, told Spaceflight Insider. “All of the components, the lines, the subsystems were redesigned and checked out before the test.”

The GEER team did a materials study that was spread out over three different tests. The tests were over 10-day, 20-day, and 40-day periods. Those tests demonstrated what kind of component materials worked best to facilitate a Venus environment test, and they made their selection of component materials based on those results. The components included valves, heaters, sensors, gas mixers, flow meters, and tubing.

“So all of the components, the lines, the subsystems, were redesigned and checked out before the test,” Nakely said. “Some of the new capabilities we added were real-time gas analysis. And that’s a big one. That allows us to take gas samples directly from the GEER vessel and analyze them in just a couple of minutes, and know exactly what the gas composition is, and from there we can adjust it, add more gas, or adjust the chemical composition. That’s a big addition we made.”

That new capability was essential to extending the Venus surface condition test to an 80-day experiment. And the redesign with the severe service parts helped make that real-time gas analysis capability possible.

“Some materials that perform really well on Earth do not perform well on Venus,” Nakely said. “No one really knows what will perform well on Venus. That’s what GEER is for.”

“I can guarantee you every time we run something in GEER we see something that makes our jaws drop,” Harvey added. “Things just aren’t behaving in the way your intuition based on Earth would lead you to expect. And whether you are a scientist or an engineer, that’s always cool.”

GEER, the Glenn Extreme Environment Rig, with its chamber open prior to an experiment. A 40-day test in simulated Venus surface conditions was conducted in the chamber two years ago, and an 80-day test was completed this past July. Scientists at Case Western Reserve University in Cleveland, Ohio, exposed a number of basaltic volcanic minerals to the simulated Venus environment to observe and analyze their reaction. An experiment in GEER’s simulated Venus environment was also completed earlier this year, testing the durability of silicon carbide semiconductor circuits, which may be used in instrumentation for future missions to Venus’ surface. Photo Credit: NASA Glenn

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Ariane 5 to launch 2 satellites to geostationary transfer orbit

Ariane 5 to launch 2 satellites to geostationary transfer orbit:

Intelsat37e is one of two satellites an Ariane 5 will send into orbit for the mission designated VA239. Image Credit: Arianespace

For the fifth time in 2017, Arianespace will send an Ariane 5 rocket into space. The flight will orbit commercial communication satellites for two international customers: Intelsat and Broadcasting Satellite System Corporation (B-SAT), a leading broadcasting satellite operator in Japan.

The Intelsat 37e satellite will support Africa, Europe, Central Africa, and Latin America, while BSAT-4a will provide Direct-to-Home (DTH) television service in Japan.

Improving satcom capabilities

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Stationed in geosynchronous orbit at 342° E longitude, Intelsat 37e will be situated over the mid-Atlantic. Weighing in at a hefty 14,193 pounds (6,438 kilograms), the satellite is the fifth of Intelsat’s EpicNG series of high-throughput satellites built by Boeing.

Intelsat 37e includes fixed C-band, and steerable spot Ku-band and Ka-band beams, which allows the spacecraft to optimize its services to meet the requirements of its regional customers. It is the first satellite to offer interconnectivity between three different bands. Additionally, the next-generation satellite will be used in wireless backhaul, enterprise Very Small Aperture Terminal (VSAT), and mobility networks.

The satellite Intelsat 37e is replacing, Intelsat 901, was launched in 2001 and has exceeded its estimated 13-year service life.

BSAT-4a is Arianespace’s ninth launch for B-SAT and its 30th launch contract for a geostationary commercial satellite in Japan. The 7,760-pound (3,520-kilogram) satellite, which will be stationed over the equator at 110° E, carries 24 Ku-band transponders. It will expand the availability of high-definition and 4K/8K ultra-high-definition television in that country. The spacecraft bus is based on SSL‘s SSL 1300 platform.

Both satellites are designed to provide service for 15 years or longer.

Ready to go

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On Sept. 1, 2017, the Ariane 5 ECA flight, designated VA239 by Arianespace, was cleared for launch. The rocket will roll out from the Guiana Space Centre’s Final Assembly Building in Kourou, French Guiana Sept. 4 to the ELA-3 launch zone.

Liftoff will occur Sept. 5, with a 33-minute launch window opening at 6:51 p.m. local time in French Guiana (5:51 p.m. EDT / 21:51 GMT). After achieving an initial orbit, Intelsat 37e, as the top payload “passenger”, will be deployed first, followed by BSAT-4a.

BSAT-4a is one of two satellites an Ariane 5 will send into orbit for the mission designated VA239. Image Credit: Arianespace

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FINESSE mission to investigate atmospheres of hundreds of alien worlds

FINESSE mission to investigate atmospheres of hundreds of alien worlds:

Artist’s concept of the FINESSE spacecraft. Image Credit: NASA / JPL

One of NASA’s proposed missions, known as the Fast INfrared Exoplanet Spectroscopy Survey Explorer (FINESSE), could greatly improve our understanding of extrasolar worlds. If selected for development, the spacecraft will investigate at least 500 exoplanet atmospheres, providing detailed information about climate processes on distant alien planets.

FINESSE has been recently chosen by NASA for concept studies and evaluations. It is one of the agency’s six astrophysics Explorers Program proposals that could be selected by 2019 to proceed with construction and launch.

The mission’s main objective is to study the processes that govern planet formation and global climate. It will investigate the mechanisms that establish the atmospheric chemical composition of exoplanets as well as the processes involved in atmospheric evolution.

“FINESSE will spectroscopically observe the atmospheres of many hundreds of transiting exoplanets to measure their molecular abundances and thermal profiles,” Robert Zellem, FINESSE science team member at NASA’s Jet Propulsion Laboratory (JPL), told Astrowatch.net.

In order to conduct the planned studies, FINESSE will use the transit method. It will measure how a planet’s atmosphere absorbs light from its host star as a function of wavelength. This will allow it to infer the molecules in the planet’s atmosphere.

“By doing this for hundreds of planets, FINESSE will determine how planets form and the crucial factors that establish planetary climate,” Zellem said.

These observations will require a proper imaging system. That is why the FINESSE spacecraft will be equipped with a telescope with a 75-centimeter (29.5-inch) primary mirror and a spectrometer that will observe planets in the visible and infrared wavelengths (from 0.5 to 5 microns).

According to Zellem, wide spectral coverage will enable FINESSE to measure the abundances of molecules such as water, methane, carbon dioxide, and carbon monoxide as well as look for the presence of clouds and hazes.

Data collected by the spacecraft are expected to provide important information that could improve our knowledge about various exoplanets, from rocky terrestrial planets to gas giants like Jupiter. FINESSE could help us discover what these alien worlds are like, determining what makes them they way they are, and allowing this knowledge to be applied in the broader planetary context, including the search for life outside of the Solar System.

If selected for the development, FINESSE is targeted for the launch around 2023. Zellem hopes that during its operational lifetime of two years it will carry out important observations of even more than 1,000 extrasolar worlds.

“FINESSE has the capability in its two-year mission to observe the atmospheres of over 1000 transiting exoplanets,” he concluded.

http://www.spaceflightinsider.com/wp-content/uploads/2017/09/Transit-method-single-planet.mp4

Video courtesy of NASA / JPL

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Transit-method-single-planet.mp4

Second GPS III satellite completes strenuous launch environment test

Second GPS III satellite completes strenuous launch environment test:

Artist’s rendering of a GPS III satellite. Image Credit: Lockheed Martin

Before a satellite can begin its operational life on orbit, it must first survive the extreme sound pressure and punishing vibrations caused by over 700,000 pounds-force (3,110 kilonewtons) of rocket thrust. On July 13, 2017, Lockheed Martin‘s second GPS III satellite (GPS III SV02) successfully completed acoustic environmental testing.

During the acoustic testing, the GPS III SV02 satellite was blasted by high-powered horns capable of producing sound up to 140 decibels. This is about as noisy as an aircraft carrier deck and is loud enough to shake loose anything on the satellite not properly attached.

“With this launch-simulation test, we are talking about sophisticated, advanced satellite technology and electronics enduring tremendous forces and then working flawlessly afterward,” said Mark Stewart, Lockheed Martin’s vice president for Navigation Systems. “Passing this test with GPS III SV02 further validates the robustness of our GPS III design. We credit this success and risk-retirement to all the pathfinding work we accomplished early in the program.”

The GPS III SV02 satellite is part of the U.S. Air Force’s next generation of GPS satellites. GPS III will have three times greater accuracy than current GPS satellites and up to eight times improved anti-jamming capabilities. The satellites have a designed life expectancy of up to 15 years – 25 percent longer than the latest GPS satellites currently in orbit.

The GPS III satellites will broadcast the new L1C civil signal that will make them the first GPS satellites to be interoperable with other international global navigational systems. The L1C signal will achieve full operational potential when broadcast from at least 24 GPS III satellites, currently projected for the late 2020s.

On July 13, 2017, the U.S. Air Force’s second GPS III space vehicle (GPS III SV 02) successfully completed acoustic testing. The test simulated the extreme sound wave pressure and pounding vibrations generated by more than 700,000 lbf of thundering rocket thrust during launch. During acoustic testing, the GPS III SV02 satellite was continuously blasted with deafening sound reaching 140 decibels in a specialized test chamber equipped with high-powered horns. Passing this test [has] further validated the robustness of Lockheed Martin’s GPS III design. Photo & Caption Credit: Lockheed Martin

GPS III SV02 is Lockheed Martin’s second GPS III satellite to complete acoustic testing. GPS III SV01 completed acoustic testing in fall 2015 and is currently in storage awaiting its expected 2018 launch.

The GPS III SV02 satellite is currently being prepared for Thermal Vacuum (TVAC) testing, where it will be subjected to extreme heat and cold in zero atmospheres, simulating conditions on-orbit. The satellite is expected to be delivered to the U.S. Air Force in early 2018.

GPS III SV02 is the second of 10 GPS satellites that Lockheed Martin is manufacturing for the Air Force at the company’s GPS III processing facility near Denver, Colorado. The $128 million factory includes a specialized cleanroom and testing chambers designed to streamline spacecraft production.

GPS III satellite design includes a modular architecture that allows for the addition of new technology as it becomes available or as mission needs change. Satellites using this design are compatible with both the Air Force’s next-generation Operational Control System (OTX) and the existing GPS constellation.

Video courtesy of Lockheed Martin 

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New Horizons sets flight plan for 2nd target; IAU accepts Pluto system names

New Horizons sets flight plan for 2nd target; IAU accepts Pluto system names:

Artist’s concept of NASA’s New Horizons spacecraft flying by a possible binary 2014 MU₆₉ on Jan. 1, 2019. Early observations of MU69 hint at the Kuiper Belt object being either a binary orbiting pair or a contact (stuck together) pair of nearly like-sized bodies with diameters near 20 and 18 kilometers (12 and 11 miles). Image & Caption Credit: Carlos Hernandez / NASA

NASA’s New Horizons mission has filed a flight plan for its January 1, 2019, flyby of Kuiper Belt Object (KBO) 2014 MU₆₉, which will bring the spacecraft three times closer to its second target than it came to Pluto during the upcoming encounter.

New Horizons’ flyby of MU69

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At a distance of more than four billion miles (6.5 billion kilometers) from Earth and approximately one billion miles (1.5 billion kilometers) beyond Pluto, the flyby will be the furthest ever encounter between a spacecraft and a planetary body.

The plan calls for the probe to pass within just 2,175 miles (3,500 kilometers) of the KBO, allowing the spacecraft’s cameras to capture images and data at higher resolutions than those taken at Pluto.

An artist’s concept of Kuiper Belt Object 2014 MU₆₉, the next flyby target for NASA’s New Horizons mission. This binary concept is based on telescope observations made at Patagonia, Argentina, on July 17, 2017, when MU69 passed in front of a star. New Horizons scientists theorize that it could be a single body with a large chunk taken out of it, or two bodies that are close together or even touching. Image & Caption Credit: Alex Parker / NASA / JHU-APL / SwRI 

New Horizons’ highest-resolution camera, the Long Range Reconnaissance Imager (LORRI), has imaged details as small as 600 feet (183 meters) in diameter on Pluto’s surface; however, on MU69, it will be able to resolve details down to a diameter of 230 feet (70 meters).

“We’re planning to fly closer to MU69 than to Pluto to get even higher resolution imagery and other datasets. The science should be spectacular,” emphasized mission Principal Investigator Alan Stern of the Southwest Research Institute (SwRI) in Boulder, Colorado.

MU69, which will become the farthest world ever visited by a spacecraft, will be studied with all seven of New Horizons’ science instruments, which will study its geology, geophysics, and composition as well as search for an atmosphere and possible moons.

Observations of the KBO conducted in July when it passed in front of a star suggest that it could be a binary system composed of two objects or a single object with two lobes.

New Horizons will look down on the KBO’s celestial north as it cruises by the object(s).

As done for the Pluto flyby, mission scientists and engineers have prepared an alternate flight plan that will be followed if debris is detected near MU69.

Even if the contingency plan has to be used, the probe will still come within 6,000 miles (10,000 kilometers) of the KBO, in contrast to 7,800 miles (12,500 kilometers) for Pluto.

NASA Planetary Science Director Jim Green praised New Horizons for repeatedly pushing the boundaries of what is possible in robotic space exploration.

“I couldn’t be more excited about this encore performance from New Horizons,” he said.

In deciding on this flight path, the mission team considered a variety of factors, including MU69’s size and shape, the desire for high-quality images, the possibility of hazardous debris nearby, and the capabilities of the spacecraft and its seven science instruments, noted team member John Spencer, also of SwRI.

On Monday, September 11, the spacecraft will be woken up from a five-month hibernation in preparation for its 16-month journey to MU69.

Names of features on Pluto officially adopted

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While the spacecraft speeds toward its second target, the International Astronomical Union (IAU) has announced its formal adoption of 14 names for features on Pluto, Charon, and the system’s four small moons.

NASA’s New Horizons spacecraft captured this high-resolution enhanced color view of Pluto on July 14, 2015. (Click to enlarge) Image Credit: NASA / JHU-APL / SwRI

These include Tombaugh Regio for the “heart” feature on Pluto’s surface, Sputnik Planitia for the icy plain on the left side of the heart, Burney crater for a crater west of the heart, Voyager Terra for a region northwest of the heart, and several more.

Tombaugh Regio is named for American astronomer Clyde Tombaugh, who discovered Pluto in 1930. Sputnik Planitia is named for the first satellite ever in space, the former Soviet Union’s Sputnik 1.

Burney crater honors Venetia Burney Phair, a British girl who, as an 11-year-old in 1930, suggested the name “Pluto” for the new discovery.

Voyager Terra honors NASA’s twin Voyager spacecraft, launched 40 years ago.

The many names assigned to mountain ranges, plains, regions, craters, and valleys on Pluto and its moons came from public input solicited as part of the “Our Pluto” project, a joint effort between the New Horizons mission, the IAU, and the SETI Institute of Mountain View, California, just prior to the Pluto flyby.

Names were sought for a variety of themes, including key space missions, underworld mythology, historic explorers, engineers, and scientists connected to Pluto and the Kuiper Belt, and even fictional locations from popular fantasy and science fiction literature, television, and movies.

“The approved designations honor many people and space missions who paved the way for the historic exploration of Pluto and the Kuiper Belt, the farthest worlds ever explored,” Stern said.

Rita Schultz, chair of the IAU Working Group for Planetary System Nomenclature, thanked both the public and members of the mission team for the name suggestions.

Along with Stern, mission scientists Mark Showalter, Ross Beyer, Will Grundy, William McKinnon, Jeff Moore, Cathy Olkin, Paul Schenk, and Amanda Zangari participated in New Horizons’ Nomenclature Working Group, which worked in concert with the IAU group.

“I’m delighted that most of the approved names were originally recommended by members of the public,” said Showalter of the SETI Institute.

The 14 names approved are only the first proposed by the mission team. Many more will be submitted by New Horizons scientists to the IAU in the near future.

The following names have been approved:

Tombaugh Regio honors Clyde Tombaugh (1906–1997), the U.S. astronomer who discovered Pluto in 1930 from Lowell Observatory in Arizona.

Burney crater honors Venetia Burney (1918–2009) who, as an 11-year-old schoolgirl, suggested the name “Pluto” for Clyde Tombaugh’s newly discovered planet. Later in life, she taught mathematics and economics.

Sputnik Planitia is a large plain named for Sputnik 1, the first space satellite, launched by the Soviet Union in 1957.

Tenzing Montes and Hillary Montes are mountain ranges honoring Tenzing Norgay (1914–1986) and Sir Edmund Hillary (1919–2008), the Indian/Nepali Sherpa and New Zealand mountaineer were the first to reach the summit of Mount Everest and return safely.

Al-Idrisi Montes honors Ash-Sharif al-Idrisi (1100–1165/66), a noted Arab mapmaker and geographer whose landmark work of medieval geography is sometimes translated as “The Pleasure of Him Who Longs to Cross the Horizons.”

Djanggawul Fossae defines a network of long, narrow depressions named for the Djanggawuls, three ancestral beings in indigenous Australian mythology who traveled between the island of the dead and Australia, creating the landscape and filling it with vegetation.

Sleipnir Fossa is named for the powerful, eight-legged horse of Norse mythology that carried the god Odin into the underworld.

Virgil Fossae honors Virgil, one of the greatest Roman poets and Dante’s fictional guide through hell and purgatory in the Divine Comedy.

Adlivun Cavus is a deep depression named for Adlivun, the underworld in Inuit mythology.

Hayabusa Terra is a large land mass saluting the Japanese spacecraft and mission (2003–2010) that performed the first asteroid sample return.

Voyager Terra honors the pair of NASA spacecraft, launched in 1977, that performed the first “grand tour” of all four giant planets. The twin Voyager spacecraft are now probing the boundary between the Sun and interstellar space.

Tartarus Dorsa is a ridge named for Tartarus, the deepest, darkest pit of the underworld in Greek mythology.

Elliot crater recognizes James L. Elliot (1943–2011), an MIT researcher who pioneered the use of stellar occultations to study the Solar System – leading to discoveries such as the rings of Uranus and the first detection of Pluto’s thin atmosphere.

Pluto’s first official surface-feature names are marked on this map, compiled from images and data gathered by NASA’s New Horizons spacecraft during its flight through the Pluto system in 2015. Image & Caption Credit: NASA / JHU-APL / SwRI / Ross Beyer

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Enigma of Jupiter’s powerful auroras

Enigma of Jupiter’s powerful auroras:

This is a reconstructed view of Jupiter’s northern lights through the filters of the Juno Ultraviolet Imaging Spectrograph instrument on Dec. 11, 2016, as the Juno spacecraft approached Jupiter, passed over its poles, and plunged toward the equator. Such measurements present a real challenge for the spacecraft’s science instruments: Juno flies over Jupiter’s poles at 30 miles (50 kilometers) per second – more than 100,000 miles per hour (44.7 km/s) – speeding past auroral forms in a matter of seconds. Image & Caption Credit: Bertrand Bonfond / NASA / JPL-Caltech

On Earth, the swirling, entrancing beauty of the auroras, which are generally isolated to the polar regions of the planet, are fairly well-understood processes. These visual light shows are caused by the interaction of charged particles from the Sun interacting with particles in the atmosphere along the area where the Earth’s magnetosphere, a protective magnetic bubble that is generated deep within the core of the planet, surrounds and connects to the Earth’s dipoles (magnetic north and south poles). This same understanding of auroral processes cannot be said of the incredibly powerful Jovian auroras observed by NASA’s Juno spacecraft.

A new paper, published in the September 7th edition of the journal Nature, confirms data from the Juno spacecraft which indicates that Jupiter’s auroras are being generated by a mysterious process instead of being produced by the interaction of particles from the solar wind with the magnetosphere, as they are on Earth.

This image, created with data from Juno’s Ultraviolet Imaging Spectrograph, marks the path of Juno’s readings of Jupiter’s auroras, highlighting the electron measurements that show the discovery of the so-called discrete auroral acceleration processes indicated by the “inverted Vs” in the lower panel. Image & Caption Credit: Randy Gladstone / NASA / JPL-Caltech / SwRI

The auroral process on Jupiter, whereby electrons are being accelerated toward the planet’s atmosphere and then shot up out of the atmosphere aligned along the magnetic field lines at energies of up to 400,000 electron volts, is 10–30 times higher than the most intense auroras – known as discrete auroras – observed in Earth’s polar regions.

The Juno spacecraft, which has been in orbit around Jupiter since July 4, 2016, has been gathering some spectacular images and data for more than a year. The data has given scientists huge mysteries to solve along with the insights they have received regarding the intense processes occurring within the gas giant.

At a press conference on May 25, 2017, Scott Bolton, the principal investigator of the Juno mission, said: “There is so much going on here that we didn’t expect that we have had to take a step back and begin to rethink of this as a whole new Jupiter.”

Jupiter’s auroras are definitely one of those unexpected areas.

The Jupiter Energetic-particle Detector Instrument (JEDI) on NASA’s Juno spacecraft was built by Johns Hopkins University’s Applied Physics Laboratory (JHU-APL). Barry Mauk who leads the team working on the ultraviolet spectroscopy and energetic particle detection instruments, observed signatures of extremely powerful electric potentials.

The extreme power of the signatures wasn’t overly surprising considering the extreme nature of nearly everything at Jupiter, but what was very surprising was the movement of the particles and trying to determine where and how they are being generated.

Whereas Earth auroras are driven by particles moving downward into the poles of the magnetosphere, Jupiter’s auroras are caused by stochastic, or turbulent, unpredictable acceleration processes that end up accelerating particles out of Jupiter’s magnetic north pole.

“At Jupiter, the brightest auroras are caused by some kind of turbulent acceleration process that we do not understand very well,” said Mauk. “There are hints in our latest data indicating that as the power density of the auroral generation becomes stronger and stronger, the process becomes unstable and a new acceleration process takes over. But we’ll have to keep looking at the data.”

Jupiter has become a sort of physics lab for worlds outside of the Solar System. The giant planet’s ability to accelerate these charged particles to such huge energies gives scientists ideas and understanding for how worlds in far distant stellar planetary systems may also accelerate particles. The forces that are driving the Jovian auroras also give hints and suggestions about space weather and its impact on Earth as well as on other bodies in the Solar System and beyond.

In addition, Mauk said: “The highest energies that we are observing within Jupiter’s auroral regions are formidable. These energetic particles that create the auroras are part of the story in understanding Jupiter’s radiation belts, which pose a challenge to Juno and to upcoming missions to Jupiter under development. Engineering around the debilitating effects of radiation has always been a challenge to spacecraft engineers for missions at Earth and elsewhere in the Solar System.

“What we learn here, and from spacecraft like NASA’s Van Allen Probes and Magnetospheric Multiscale mission (MMS) that are exploring Earth’s magnetosphere, will teach us a lot about space weather and protecting spacecraft and astronauts in harsh space environments. Comparing the processes at Jupiter and Earth is incredibly valuable in testing our ideas of how planetary physics works.”

The images contain intensities from three spectral ranges, false-colored red, green, and blue, providing qualitative information on precipitating electron energies (high, medium, and low, respectively). An estimate of the magnetic projections of the Juno trajectory is shown (red lines), determined using the VIPAL24 magnetic field model with large uncertainties, with tick marks in steps of 1 h (see Methods). The short yellow arcs with arrows indicate the direction to the Sun when the image was taken. The blue-green lines are the average positions of the main ultraviolet aurora for the south and north, respectively. (a) Jupiter’s southern aurora taken during the fourth perijove (PJ4) encounter on 2 February 2017. (b) Jupiter’s northern aurora taken during the third perijove (PJ3) encounter on 11 December 2016. Image & Caption Credit: B. H. Mauk et al. / Nature

NASA’s Jet Propulsion Laboratory (JPL), Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute (SwRI) in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for NASA’s Science Mission Directorate. Lockheed Martin Space Systems, Denver, built the spacecraft.



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The Sun has produced a whole bunch of solar flares this week

The Sun has produced a whole bunch of solar flares this week:

While the hurricanes popping up in the Atlantic has captured everyone’s attention, the Sun has had its own active week as well. A total of six solar flares have erupted from the same active sunspot since Monday — including the largest flare the Sun has produced in its current cycle.

Sunspots are cool, dark regions on the Sun’s surface with strong magnetic fields. These solar phenomena pop up on the Sun from time to time, sometimes relatively frequently. In fact, the Sun has a roughly 11-year sunspot cycle — the result of the its changing magnetic field. Magnetic material inside the Sun is always moving and rising to the surface, and it eventually causes the Sun’s north and south poles to flip. Because of this, the Sun alternates between...

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Hubble's Megamaser Galaxy

Hubble's Megamaser Galaxy: MCG+01-38-005 (below) is a special kind of megamaser; the galaxy’s active galactic nucleus pumps out huge amounts of energy, stimulating clouds of surrounding water.

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Cassini Conduct a Final Flyby of Titan Before Crashing into Saturn

Cassini Conduct a Final Flyby of Titan Before Crashing into Saturn:

When the Cassini spacecraft arrived around Saturn on July 1st, 2004, it became the fourth space probe to visit the system. But unlike the Pioneer 11 and Voyager 1 and 2 probes, the Cassini mission was the first to establish orbit around the planet for the sake of conducting long-term research. Since that time, the spacecraft and its accompanying probe – the Huygens lander – have revealed a startling amount about this system.

On Friday, September 15th, the Cassini mission will official end as the spacecraft descends into Saturn’s atmosphere. In part of this final maneuver, Cassini recently conducted one last distant flyby of Titan. This flyby is being referred to informally as “the goodbye kiss” by mission engineers, since it is providing the gravitational push necessary to send the spacecraft into Saturn’s upper atmosphere, where it will burn up.

In the course of this flyby, the spacecraft made its closest approach to Titan on Tuesday, September 12th, at 12:04 p.m. PDT (3:04 p.m. EDT), passing within 119,049 kilometers (73,974 mi) of the moon’s surface. The maneuver was designed to slow the probe down and lower the altitude of its orbit around the planet, which will cause it to descend into Saturn’s atmosphere in a few day’s time.

Artist’s conception of Cassini winging by Saturn’s moon Titan (right) with the planet in the background. Credit: NASA/JPL-Caltech

The flyby also served as an opportunity to collect some final pictures and data on Saturn’s largest moon, which has been a major focal point for much of the Cassini-Huygens mission. These will all be transmitted back to Earth at 18:19 PDT (21:19 EDT) when the spacecraft makes contact, and navigators will use this opportunity to confirm that Cassini is one course for its final dive.

All told, the spacecraft made hundreds of passes over Titan during its 13-year mission. These included a total of 127 precisely targeted encounters at close and 4far range (like this latest flyby). As Cassini Project Manager Earl Maize, from NASA’s Jet Propulsion Laboratory, said in a NASA press statement:

“Cassini has been in a long-term relationship with Titan, with a new rendezvous nearly every month for more than a decade. This final encounter is something of a bittersweet goodbye, but as it has done throughout the mission, Titan’s gravity is once again sending Cassini where we need it to go.”

In the course of making its many flybys, the Cassini spacecraft revealed a great deal about the composition of Titan’s atmosphere, its methane cycle (similar to Earth’s hydrological cycle) and the kinds of weather it experiences in its polar regions. The probe also provided high-resolution radar images of Titan’s surface, which included topography and images of its northern methane lakes.

Artist depiction of Huygens lander touching down on the surface of Saturn’s largest moon Titan. Credit: ESA

Cassini’s first flyby of Titan took place on July 2nd, 2004 – a day after the spacecraft’s orbital insertion – where it approached to within 339,000 km (211,000 mi) of the moon’s surface. On December 25th, 2004, Cassini released the Huygens lander into the planet’s atmosphere. The probe touched down on January 14th, 2005, taking hundreds of pictures of the moon’s surface in the process.

In November of 2016, the spacecraft began the Grand Finale phase of its mission, where it would make 22 orbits between Saturn and its rings. This phase began with a flyby of Titan that took it to the gateway of Saturn’s’ F-ring, the outermost and perhaps most active ring around Saturn. This was followed by a final close flyby of Titan on April 22nd, 2017, taking it to within 979 km (608 mi) of the moon’s surface.

Throughout its mission, Cassini also revealed some significant things about Saturn’s atmosphere, its hexagonal storms, its ring system, and its extensive system of moons. It even revealed previously-undiscovered moons, such as Methone, Pallene and Polydeuces. Last, but certainly not least, it conducted studies of Saturn’s moon Enceladus that revealed evidence of a interior ocean and plume activity around its southern polar region.

These discoveries are part of the reason why the probe will end its mission by plunging into Saturn’s atmosphere, about two days and 16 hours from now. This will cause the probe to burn up, thus preventing contamination of moons like Titan and Enceladus, where microbial life could possibly exist. Finding evidence of this life will be the main focus of future missions to the Saturn system, which are likely to launch in the next decade.

So long and best wishes, Cassini! You taught so much in the past decade and we hope to follow up on it very soon. We’ll all miss you when you go!



Further Reading: NASA

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Geocolor Image of Hurricane Irma

Geocolor Image of Hurricane Irma: The NOAA satellite GOES-16 captured this geocolor image of Hurricane Irma passing the eastern end of Cuba at about 8:00 a.m. EDT, Sept. 8, 2017. Created by NOAA's partners at the Cooperative Institute for Research in the Atmosphere, the experimental imagery enhancement displays geostationary satellite data in different ways for day or night.

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So Far from Home

So Far from Home: With this view, Cassini captured one of its last looks at Saturn and its main rings from a distance.

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The Heart Nebula in Hydrogen, Oxygen, and Sulfur

The Heart Nebula in Hydrogen, Oxygen, and Sulfur:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2017 August 27

The Heart Nebula in Hydrogen, Oxygen, and Sulfur

Image Credit & Copyright: Peter Jenkins


Explanation: What powers the Heart Nebula? The large emission nebula dubbed IC 1805 looks, in whole, like a heart. The nebula's glow -- as well as the shape of the gas and dust clouds -- is powered by by stellar winds and radiation from massive hot stars in the nebula's newborn star cluster Melotte 15. This deep telescopic image maps the pervasive light of narrow emission lines from atoms of hydrogen, oxygen, and sulfur in the nebula. The field of view spans just over two degrees on the sky, so that it appears larger than four times the diameter of a full moon. The cosmic heart is found in the constellation of Cassiopeia, the boastful mythical Queen of Aethiopia .

Tomorrow's picture: double eclipse

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A Fleeting Double Eclipse of the Sun

A Fleeting Double Eclipse of the Sun:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2017 August 28

A Fleeting Double Eclipse of the Sun

Image Credit & Copyright: Simon Tang


Explanation: Last week, for a fraction of a second, the Sun was eclipsed twice. One week ago today, many people in North America were treated to a standard, single, partial solar eclipse. Fewer people, all congregated along a narrow path, experienced the eerie daytime darkness of a total solar eclipse. A dedicated few with fast enough camera equipment, however, were able to capture a double eclipse -- a simultaneous partial eclipse of the Sun by both the Moon and the International Space Station (ISS). The Earth-orbiting ISS crossed the Sun in less than a second, but to keep the ISS from appearing blurry, exposure times must be less than 1/1000th of a second. The featured image composite captured the ISS multiple times in succession as it zipped across the face of the Sun. The picture was taken from Huron, California in a specific color emitted by hydrogen which highlights the Sun's chromosphere, a layer hotter and higher up than the usually photographed photosphere.

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Tomorrow's picture: my blue saturn

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Saturn in Blue and Gold

Saturn in Blue and Gold:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2017 August 29

Saturn in Blue and Gold

Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA


Explanation: Why is Saturn partly blue? The featured picture of Saturn approximates what a human would see if hovering close to the giant ringed world. The image was taken in 2006 March by the robot Cassini spacecraft now orbiting Saturn. Here Saturn's majestic rings appear directly only as a thin vertical line. The rings show their complex structure in the dark shadows they create on the image left. Saturn's fountain moon Enceladus, only about 500 kilometers across, is seen as the bump in the plane of the rings. The northern hemisphere of Saturn can appear partly blue for the same reason that Earth's skies can appear blue -- molecules in the cloudless portions of both planet's atmospheres are better at scattering blue light than red. When looking deep into Saturn's clouds, however, the natural gold hue of Saturn's clouds becomes dominant. It is not known why southern Saturn does not show the same blue hue -- one hypothesis holds that clouds are higher there. It is also not known why Saturn's clouds are colored gold. Next month, Cassini will end its mission with a final dramatic dive into Saturn's atmosphere.

Eclipses 2017: Memorable images submitted to APOD -- please "Like" your favorites.

Tomorrow's picture: princely eclipse

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A Waterspout in Florida

A Waterspout in Florida:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2017 September 3

Explanation: What's happening over the water? Pictured here is one of the better images yet recorded of a waterspout, a type of tornado that occurs over water. Waterspouts are spinning columns of rising moist air that typically form over warm water. Waterspouts can be as dangerous as tornadoes and can feature wind speeds over 200 kilometers per hour. Some waterspouts form away from thunderstorms and even during relatively fair weather. Waterspouts may be relatively transparent and initially visible only by an unusual pattern they create on the water. The featured image was taken in 2013 July near Tampa Bay, Florida. The Atlantic Ocean off the coast of Florida is arguably the most active area in the world for waterspouts, with hundreds forming each year. Some people speculate that waterspouts are responsible for some of the losses recorded in the Bermuda Triangle.

Saturns Rings from the Inside Out

Saturns Rings from the Inside Out:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2017 September 4

Explanation: What do Saturn's rings look like from Saturn? Images from the robotic spacecraft Cassini are providing humanity with this unprecedented vantage point as it nears the completion of its mission. Previous to Cassini's Grand Finale orbits, all images of Saturn's majestic ring system were taken from outside of the rings looking in. Pictured in the inset is the remarkable video, while the spacecraft's positions are depicted in the surrounding animation. Details of the complex rings are evident as the short time-lapse sequence begins, while the paper-thin thickness of the rings becomes apparent near the video's end. The featured images were taken on August 20. Cassini has only a few more orbits around Saturn left before it is directed to dive into the giant planet on September 15.

The Flash Spectrum of the Sun

The Flash Spectrum of the Sun:

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2017 September 7

The Flash Spectrum of the Sun

Image Credit & Copyright: Yujing Qin (University of Arizona)


Explanation: In clear Madras, Oregon skies, this colorful eclipse composite captured the elusive chromospheric or flash spectrum of the Sun. Only three exposures, made on August 21 with telephoto lens and diffraction grating, are aligned in the frame. Directly imaged at the far left, the Sun's diamond ring-like appearance at the beginning and end of totality brackets a silhouette of the lunar disk at maximum eclipse. Spread by the diffraction grating into the spectrum of colors toward the right, the Sun's photospheric spectrum traces the two continuous streaks. They correspond to the diamond ring glimpses of the Sun's normally overwhelming disk. But individual eclipse images also appear at each wavelength of light emitted by atoms along the thin, fleeting arcs of the solar chromosphere. The brightest images, or strongest chromospheric emission, are due to Hydrogen atoms. Red hydrogen alpha emission is at the far right with blue and purple hydrogen series emission to the left. In between, the brightest yellow emission is caused by atoms of Helium, an element only first discovered in the flash spectrum of the Sun.

Tomorrow's picture: a great gig in the sky

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The Great Gig in the Sky

The Great Gig in the Sky:

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2017 September 8

Explanation: There were no crowds on the beach at Phillips Lake, Oregon on August 21. But a few had come there to stand, for a moment, in the dark shadow of the Moon. From the beach, this unscripted mosaic photo records their much anticipated solar eclipse. In two vertical panels it catches the last few seconds of totality and the first instant of 3rd contact, just as the eclipse ends and sunlight faintly returns. Across the US those gathered along the path of totality also took pictures and shared their moment. And like those at Phillips Lake they may treasure the experience more than any planned or unplanned photograph of the total eclipse of the Sun.

Calm Waters and Geomagnetic Storm

Calm Waters and Geomagnetic Storm:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2017 September 9

Explanation: Very recognizable stars of the northern sky are a backdrop for calm waters in this moonlit sea and skyscape off Cape Cod, Massachusetts. Taken on September 7, the photo also records a colorful display of northern lights or aurora borealis triggered by a severe geomagnetic storm. Visible crossing the Sun, the giant solar active region responsible, AR 2673, is much larger than planet Earth. It has produced the strongest flare of the current solar cycle and and the Earth-directed coronal mass ejection in the last few days.