Jupiter Archives

February 18, 2017 by Matt Williams

Juno Will Get No Closer To Jupiter Due To Engine Troubles

Jupiter’s south pole. captured by the JunoCam on Feb. 2, 2017, from an altitude of about 62,800 miles (101,000 kilometers) above the cloud tops. Credits: NASA/JPL-Caltech/SwRI/MSSS/John Landino

On July 4th, 2016, the Juno mission established orbit around Jupiter, becoming the second spacecraft in history to do so (after the Galileo probe). Since then, the probe has been in a regular 53.4-day orbit (known as perijove), moving between the poles to avoid the worst of its radiation belts. Originally, Juno’s mission scientists had been hoping to reduce its orbit to a 14-day cycle so the probe could make more passes to gather more data.

To do this, Juno was scheduled for an engine burn on Oct. 19th, 2016, during its second perijovian maneuver. Unfortunately, a technical error prevented this from happening. Ever since, the mission team has been pouring over mission data to determine what went wrong and if they could conduct an engine burn at a later date. However, the mission team has now concluded that this won’t be possible.

The technical glitch which prevented the firing took place weeks before the engine burn was scheduled to take place, and was traced to two of the engines helium check valves. After the propulsion system was pressurized, the valves took several minutes to open – whereas they took only seconds during previous engine burns. Because of this, the mission leaders chose to postpone the firing until they could get a better understanding of why the glitch happened.

This amateur-processed image was taken on Dec. 11th, 2016, at 9:27 a.m. PST (12:27 p.m. EST), as NASA’s Juno spacecraft performed its third close flyby of Jupiter. Credits: NASA/JPL-Caltech/SwRI/MSSS/Eric Jorgensen

And after pouring over mission data from the past few months and performing calculations on possible maneuvers, Juno’s science team came to the conclusion that an engine burn might be counter-productive at this point. As Rick Nybakken, the Juno project manager at NASA’s Jet Propulsion Laboratory (JPL), explained in a recent NASA press release:

“During a thorough review, we looked at multiple scenarios that would place Juno in a shorter-period orbit, but there was concern that another main engine burn could result in a less-than-desirable orbit. The bottom line is a burn represented a risk to completion of Juno’s science objectives.”

However, this is not exactly bad news for the mission. It’s current perijove orbit takes it from one pole to the other, allowing it to pass over the cloud tops at a distance of around 4,100 km (2,600 mi) at its closest. At its farthest, the spacecraft reaches a distance of 8.1 million km (5.0 million mi) from the gas giant, which places it far beyond the orbit of Callisto.

During each pass, the probe is able to peak beneath the thick clouds to learn more about the planet’s atmosphere, internal structure, magnetosphere, and formation. And while a 14-day orbital period would allow for it to conduct 37 orbits before its mission is scheduled to wrap up, its current 53.4-day period will allow for more information to be collected on each pass.

And as Thomas Zurbuchen, the associate administrator for NASA’s Science Mission Directorate in Washington, declared:

“Juno is healthy, its science instruments are fully operational, and the data and images we’ve received are nothing short of amazing. The decision to forego the burn is the right thing to do – preserving a valuable asset so that Juno can continue its exciting journey of discovery.”

In the meantime, the Juno science team is still analyzing the returns from Juno’s four previous flybys – which took place on August 27th, October 19th, December 11th, and February 2nd, 2017, respectively. With each pass, more information is revealed about the planet’s magnetic fields, aurorae, and banded appearance. The next perijovian maneuver will take place on March 27th, 2017, and will result in more images and data being collected.

Before the mission concludes, the Juno spacecraft will also explore Jupiter’s far magnetotail, its southern magnetosphere, and its magnetopause. The mission is also conducting an outreach program with its JunoCam, which is being guided with assistance of the public. Not only can people vote on which features they want imaged with every flyby, but these images are accessible to “citizen scientists” and amateur astronomers.

Under its current budget plan, Juno will continue to operate through to July 2018, conducting a total of 12 science orbits. At this point, barring a mission extension, the probe will be de-orbited and burn up in Jupiter’s outer atmosphere. As with the Galileo spacecraft, this will be as to avoid any possibility of impact and biological contamination with one of Jupiter’s moons.

Further Reading: NASA

February 11, 2017February 15, 2017 by Matt Williams

91 Astronomers Combine 1000 Images Into One Amazing Journey to Jupiter

Using 1,000 images taken by 91 amateurs from around the world, Peter Rosen has created a high-resolution film of Jupiter's dynamic atmosphere. Credit: Peter Rosén et al. via YouTube

A renewed era of space exploration is underway. Compared to the Space Race of the 20th century, which was characterized by two superpowers locked in a game of “getting there first”, the new era is defined predominantly by cooperation and open participation. One way in which this is evident is the role played by “citizen scientists” and amateur astronomers in exploration missions.

Consider the recently-released short film titled “A Journey to Jupiter” by Peter Rosen – a photographer and digital artist in Stockholm, Sweden. Using over 1000 images taken by amateur planetary photographers from around the world, this film takes viewers on a virtual journey to the Jovian planet, showcasing its weather patterns and dynamic nature in a way that is truly inspiring.

The images that went into making this video were collected by over 91 amateur astronomers over the course of three and a half months (between December 19th, 2014 and March 31st, 2015). After Rosen collected them, he and his associates (Christoffer Svenske and Johan Warell) then spent a year remapping them into cylindrical projections. Rosen then added color corrections, and stitched all the images into a total of 107 maps.

Much like fast-motion videos that illustrate weather patterns on Earth, or the passage of the stars across the night sky, the end result of was a film that shows the motions of Jupiter’s cloud belts and its Great Red Spot in high-resolution. Some 250 revolutions of the planet are illustrated, including from the equatorial band, the south pole, and the north pole.

As Rosen told Universe Today via email, this project was the latest in a lifelong pursuit of making astronomy accessible to the public:

“I have been into Astronomy since I was a teenager in the early 1970’s and immediately I got a passion for astrophotography, and more specifically, photographing the planets. I see astronomy as a life-long passion, so it is quite normal to strive for an evolution in what you do. I had an idea growing slowly for some years that it should be possible to animate the cloud belts of Jupiter and reveal the intricate dynamics of its flows, not just taking still pictures that might point to the changes in the structures but without the obvious visual dynamics of an animation.”

“A Journey to Jupiter” was also Rosen’s contribution to the Mission Juno Pro-Amateur Collaboration Project, of which he is part. Established by Glenn Orton of NASA’s Jet Propulsion Laboratory, this effort is one of several that seeks to connect amateurs and professionals in support of space exploration. Back in May of 2016, this group met in Nice, France, for a workshop dedicated to projects and techniques related to Jupiter observations.

*Still-pic from Rosen’s “A Journey to Jupiter” video. Credit: Peter Rosen et al via Youtube.*

Among other items discussed was the limitations that missions like Juno have to deal with. While it is capable of taking very-high resolution images of Jupiter, these images are highly specific in nature. And before a team of mission scientists are able to color-correct them and stitch them together to create panoramas, etc., they are not always what you might call “visually stunning”.

However, Earth-based observatories are not hampered by this restriction, and can take multiple images of a planet over time that capture it as a whole. And thanks to the availability of sophisticated telescopes and imaging software, amateur astronomers are capable of making important contributions in this regard. And far from these being strictly for scientific purposes, there is also the added benefit of public engagement.

“This has been a very technical and scientifically correct project,” said Rosen, “but as a photographer and digital artist I also wanted to create a work of art that would inspire and appeal to people who are fascinated by the universe but who are not necessarily into astronomy.”

Of course, this does not detract from the scientific value that this film has. For example, it showcases the turbulent nature of Jupiter’s atmosphere in a way that is scientifically accurate. Hence why Ricardo Hueso Alonso – a physicist at the University of Basque Country and a member of the Planetary Virtual Observatory and Laboratory (PVOL) – plans to use the maps to measure Jupiter’s wind speeds at different latitudes.

On top of its artistic and scientific merit, “A Journey to Jupiter” also serves as a testament to the skill and capability of the today’s amateur astronomers and planetary photographers. And of course, it draws attention to the efforts of space missions such as Juno, which is currently skimming the clouds of Jupiter to obtain the most comprehensive information about the planet’s atmosphere and magnetic field to date.

Not surprisingly, this is not the first film by Rosen that combines scientific accuracy and fast-motion visuals. The short film Voyager 3, released back in June of 2014, was an homage by Rosen and six other Swedish amateur astronomers to the Voyager 1 mission. As the probe made its 28-day final approach to Jupiter in 1979, it snapped what were the most detailed images of Jupiter at the time.

These images helped to improve our understanding of the gas giant, its atmosphere, and its moons. Among other things, hey revealed the turbulent nature of Jupiter’s atmosphere, and that the Great Red Spot had changed color since the Pioneer 10 and 11 missions had flown by in 1973 and 74. Produced 35 years later, Voyager 3 was an attempt to recreate this historic event using images taken by Swedish amateur astronomers using their own ground-based telescopes.

Over the course of 90 days, Rosen and his colleagues captured one million frames of Jupiter, which resulted in 560 still images of the planet. These were then stitched together using a series of software programs (Winjupos, Photoshop CS6, Fantamorph, and StarryNightPro+) to create a simulation that gives the impression of a probe approaching the planet – i.e. like a third Voyager mission, hence the name of the film.

“As Jupiter was ideally positioned high in the sky in 2013-2014 for us living far up in the northern hemisphere, I decided that it was the right moment to give it a try, so I contacted 6 other amateurs on our local forum that shared my passion for the planets,” Rosen said. “We photographed Jupiter as often as we could during a 3-month period and I took care of the processing of the images which took me a total of 6 months.”

It is an exciting time to be alive. Not only are a greater number of national space agencies taking part in the exploration of the Solar System; but more than ever, citizen scientists, amateurs and members of the general public are able to participate in a way that was never before possible.

To view more work by Peter Rosen, be sure to check out his page at Vimeo.

Further Reading: NASA

February 10, 2017February 11, 2017 by Bob King

This Is The Highest Resolution Image Of Europa We Have … For Now

This is the highest resolution image taken by Galileo at Europa — Jupiter’s 4th largest moon — until our next mission to the planet. It was obtained at an original image scale of 19 feet (6 meters) per pixel. The gray line down the middle resulted from missing data that was not transmitted by Galileo. Credit: NASA/JPL-Caltech

In the movie 2010: The Year We Make Contact, the sequel to Stanley’s Kubrick’s 2001: A Space Odyssey, black Monoliths multiply, converge and transform Jupiter into a new star. We next hear astronaut David Bowman’s disembodied voice with this message: “All these worlds are yours except Europa. Attempt no landing there.” The newborn sun warms Europa, transforming the icy landscape into a primeval jungle. At the end, a single Monolith appears in the swamp, waiting once again to direct the evolution of intelligent life forms.

Europa’s cracked, icy surface imaged by NASA’s Galileo spacecraft in 1998. Credit: NASA/JPL-Caltech/SETI Institute

Stay away from Europa? No way. It’s just too fascinating a place with its jigsaw-puzzle ice sheets, crisscross valleys, miles of ice on top and a warm, salty ocean below. The movie was prescient — if you’re going to search for life elsewhere in the solar system, Europa’s one of the best candidates.

While we’ve sent spacecraft to photograph and study the icy moon during orbital flybys, no lander has yet to touch the surface. That may change soon. In early 2016, in response to a congressional directive, NASA’s Planetary Science Division began a pre-Phase A study to assess the science value and engineering design of a future Europa lander mission. In June 2016, NASA convened a 21-member team of scientists for the Science Definition Team (SDT). The team put together set of science objectives and measurements for the mission concept and submitted the report to NASA on Feb. 7.

This artist’s rendering illustrates a conceptual design for a potential future mission to land a robotic probe on the surface of Jupiter’s moon Europa. The lander is shown with a sampling arm extended, having previously excavated a small area on the surface. The circular dish on top is a combo high-gain antenna and camera mast, with stereo imaging cameras mounted on the back of the antenna. Three vertical shapes located around the top center of the lander are attachment points for cables that would lower the rover from a sky crane, the planned landing system for this mission concept. Credits: NASA/JPL-Caltech

The report lists three science goals for the mission. The primary goal is to search for evidence of life on Europa. The other goals are to determine the habitability of Europa by directly analyzing material from the surface, and to characterize the surface and subsurface to support future robotic exploration of Europa and its ocean.

This image from NASA’s Galileo spacecraft show the intricate detail of Europa’s icy surface. The red staining occurs in areas where briny waters from below — possibly mixed with sulfur — reach the surface. Radiation from Jupiter bombards the material, causing it to redden. Gravitational flexing of the moon as it orbits Jupiter fractures the icy crust into a chaotic landscape of snaking valleys and ice sheets. It also warms the ocean beneath the crust, potentially making it habitable. Credit: NASA/JPL-Caltech

The evidence is quite strong that Europa, with a diameter of 1,945 miles — slightly smaller than Earth’s moon — has a global saltwater ocean beneath its icy crust. This ocean has at least twice as much water as Earth’s oceans. Two things make Europa’s ocean unique and give the moon a greater chance of supporting microbial life compared to say, Ganymede and Enceladus, which also hold water reservoirs beneath their crusts.

Astronomers hypothesize that chloride salts bubble up from the icy moon’s global liquid ocean and reach the frozen surface where they are bombarded with sulfur from volcanoes on Jupiter’s innermost large moon Io. Molecular signs of life may be transported where they could be detected by a spacecraft. In this illustration, we see Europa (foreground), Jupiter (right) and Io (middle). Credit: NASA/JPL-Caltech

One: the ocean is relatively close to the surface, just 10-15 miles below the moon’s icy shell. Radiation from Jupiter (high-speed electrons and protons) bombards ice, sulfur and salts on the surface to create compounds that could trickle down into warmer regions and used by living things for growth and metabolism.

Broken plates and blocks of water ice now frozen in place in Europa’s crust suggest they floated freely for a time. Credit: NASA/JPL-Caltech

Two: While recent discoveries have shown that many bodies in the solar system either have subsurface oceans now, or may have in the past, Europa is one of only two places where the ocean appears to be in contact with a rocky seafloor (the other being Saturn’s moon Enceladus). This rare circumstance makes Europa one of the highest priority targets in the search for present-day life beyond Earth.

On Earth, chemical interactions between life and lifeless rock in deep oceans and within the outer crust provide the energy needed to power and sustain microbial life. For all we know, deep sea volcanoes belch essential elements into the salty waters spawned by the constant flexing and heating of the moon as it orbits Jupiter every 85 hours.

This mosaic of images includes the most detailed view of the surface of Jupiter’s moon Europa obtained by NASA’s Galileo mission. This observation was taken with the sun relatively high in the sky, so most of the brightness variations are due to color differences in the surface material rather than shadows. Ridge tops, brightened by frost, contrast with darker valleys, perhaps due to small temperature variations allow frost to accumulate in slightly colder, higher-elevation locations. Credit: NASA/JPL-Caltech

The SDT was tasked with developing a life-detection strategy, a first for a NASA mission since the Mars Viking mission era more than four decades ago. The report makes recommendations on the number and type of science instruments that would be required to confirm if signs of life are present in samples collected from the icy moon’s surface.

The team also worked closely with engineers to design a system capable of landing on a surface about which very little is known. Given that Europa has no atmosphere, the team developed a concept that could deliver its science payload to the icy surface without the benefit of technologies like a heat shield or parachutes.

This artist’s rendering shows NASA’s Europa mission spacecraft, which is being developed for a launch sometime in the 2020s. The spacecraft would orbit around Jupiter in order to perform a detailed investigation of Europa before a follow-up landing mission. The probe could look for “biosignatures” or molecular signs of life, such as the byproducts of metabolism, transported from the moon’s ocean to its surface. Credit: NASA/JPL-Caltech

The concept lander is separate from the solar-powered Europa multiple flyby mission, now in development for launch in the early 2020s. The spacecraft will arrive at Jupiter after a multi-year journey, orbiting the gas giant every two weeks for a series of 45 close flybys of Europa. The multiple flyby mission will investigate Europa’s habitability by mapping its composition, determining the characteristics of the ocean and ice shell, and increasing our understanding of its geology. The mission also will lay the foundation for a future landing by performing detailed reconnaissance using its powerful cameras.

We can’t help but be excited by the prospects of life-seeking missions to Europa. Sometimes wonderful things come in small packages.

January 29, 2017January 30, 2017 by Bob King

A Proposal For Juno To Observe The Volcanoes Of Io

Io and volcanic plume. Credit: NASA/JPL-Caltech

To accomplish its science objectives, NASA’s **Juno spacecraft** orbits over Jupiter’s poles and passes repeatedly through hazardous radiation belts. Two Boston University researchers propose using Juno to probe the ever-changing flux of volcanic gases-turned-ions spewed by Io’s volcanoes. Credit: NASA/JPL-Caltech

Jupiter may be the largest planet in the Solar System with a diameter 11 times that of Earth, but it pales in comparison to its own magnetosphere. The planet’s magnetic domain extends sunward at least 3 million miles (5 million km) and on the back side all the way to Saturn for a total of 407 million miles or more than 400 times the size of the Sun.

Jupiter’s large magnetic field interacts with the solar wind to form an invisible magnetosphere. If we were able to see it, it would span at least several degrees of sky. It would show its greatest extent when viewing Jupiter from the side at quadrature, when the planet stands due south at sunrise or sunset.In the artist’s depiction, the planet would be located between the two “purple eyes” — too small to see at this scale. Credit: NASA.

If we had eyes adapted to see the Jovian magnetosphere at night, its teardrop-like shape would easily extend across several degrees of sky! No surprise then that Jove’s magnetic aura has been called one of the largest structures in the Solar System.

A 5-frame sequence taken by the New Horizons spacecraft in May 2007 shows a cloud of volcanic debris from Io’s **Tvashtar volcano**. The plume extends some 200 miles (330 km) above the moon’s surface. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Io, Jupiter’s innermost of the planet’s four large moons, orbits deep within this giant bubble. Despite its small size — about 200 miles smaller than our own Moon — it doesn’t lack in superlatives. With an estimated 400 volcanoes, many of them still active, Io is the most volcanically active body in the Solar System. In the moon’s low gravity, volcanoes spew sulfur, sulfur dioxide gas and fragments of basaltic rock up to 310 miles (500 km) into space in beautiful, umbrella-shaped plumes.

This schematic of Jupiter’s magnetic environments shows the planets looping magnetic field lines (similar to those generated by a simple bar magnet), Io and its plasma torus and flux tube. Credit: John Spencer / Wikipedia CC-BY-SA3.0 with labels by the author

Once aloft, electrons whipped around by Jupiter’s powerful magnetic field strike the neutral gases and ionize them (strips off their electrons). Ionized atoms and molecules (ions) are no longer neutral but possess a positive or negative electric charge. Astronomers refer to swarms of ionized atoms as plasma.

Jupiter rotates rapidly, spinning once every 9.8 hours, dragging the whole magnetosphere with it. As it spins past Io, those volcanic ions get caught up and dragged along for the ride, rotating around the planet in a ring called the Io plasma torus. You can picture it as a giant donut with Jupiter in the “hole” and the tasty, ~8,000-mile-thick ring centered on Io’s orbit.

That’s not all. Jupiter’s magnetic field also couples Io’s atmosphere to the planet’s polar regions, pumping Ionian ions through two “pipelines” to the magnetic poles and generating a powerful electric current known as the Io flux tube. Like firefighters on fire poles, the ions follow the planet’s magnetic field lines into the upper atmosphere, where they strike and excite atoms, spawning an ultraviolet-bright patch of aurora within the planet’s overall aurora. Astronomers call it Io’s magnetic footprint. The process works in reverse, too, spawning auroras in Io’s tenuous atmosphere.

The tilt of Juno’s orbit relative to Jupiter changes over the course of the mission, sending the spacecraft increasingly deeper into the planet’s intense radiation belts. Orbits are numbered from early in the mission to late. Credit: NASA/JPL-Caltech

Io is the main supplier of particles to Jupiter’s magnetosphere. Some of the same electrons stripped from sulfur and oxygen atoms during an earlier eruption return to strike atoms shot out by later blasts. Round and round they go in a great cycle of microscopic bombardment! The constant flow of high-speed, charged particles in Io’s vicinity make the region a lethal environment not only for humans but also for spacecraft electronics, the reason NASA’s Juno probe gets the heck outta there after each perijove or closest approach to Jupiter.

Io’s flux tube directs ions down Jupiter’s magnetic field lines to create magnetic footprints of enhanced aurora in Jupiter’s polar regions. An electric current of 5 million amps flows along Io’s flux tube.Credit: NASA/J.Clarke/HST

But there’s much to glean from those plasma streams. Astronomy PhD student Phillip Phipps and assistant professor of astronomy Paul Withers of Boston University have hatched a plan to use the Juno spacecraft to probe Io’s plasma torus to indirectly study the timing and flow of material from Io’s volcanoes into Jupiter’s magnetosphere. In a paper published on Jan. 25, they propose using changes in the radio signal sent by Juno as it passes through different regions of the torus to measure how much stuff is there and how its density changes over time.

The technique is called a radio occultation. Radio waves are a form of light just like white light. And like white light, they get bent or refracted when passing through a medium like air (or plasma in the case of Io). Blue light is slowed more and experiences the most bending; red light is slowed less and refracted least, the reason red fringes a rainbow’s outer edge and blue its inner. In radio occultations, refraction results in changes in frequency caused by variations in the density of plasma in Io’s torus.

The best spacecraft for the attempt is one with a polar orbit around Jupiter, where it cuts a clean cross-section through different parts of the torus during each orbit. Guess what? With its polar orbit, Juno’s the probe for the job! Its main mission is to map Jupiter’s gravitational and magnetic fields, so an occultation experiment jives well with mission goals. Previous missions have netted just two radio occultations of the torus, but Juno could potentially slam dunk 24.

New Horizons took this photo of Io in infrared light. The Tvastar volcano is bright spot at top. At least 10 other volcanic hot spots dot the moon’s night side. Credit: NASA/JHUPL/SRI

Because the paper was intended to show that the method is a feasible one, it remains to be seen whether NASA will consider adding a little extra credit work to Juno’s homework. It seems a worthy and practical goal, one that will further enlighten our understanding of how volcanoes create aurorae in the bizarre electric and magnetic environment of the largest planet.

January 25, 2017January 25, 2017 by Nancy Atkinson

Juno Just Took One Of The Best Images Of Jupiter Ever

A portion of a new image taken by the JunoCam imager on NASA’s Juno spacecraft of Jupiter’s northern latitudes on Dec. 11, 2016. Credit: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstaedt/John Rogers.

Wow! If you’ve ever wanted to know what it would be like to hang above Jupiter’s clouds, here you go. This absolutely stunning view of Jupiter’s northern latitudes shows incredible detail of gas giant’s swirling cloudtops. And it features, in the lower left in the image below, the storm on the gas planet known as NN-LRS-1, or more colloquially, the Little Red Spot.

The JunoCam imager on NASA’s Juno spacecraft snapped this shot of Jupiter’s northern latitudes on Dec. 11, 2016. Credit: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstaedt/John Rogers.

Juno’s JunoCam, a visible light camera, is able to get never-before-seen images like this because it is doing something that no other mission to Jupiter has done.

“The spacecraft’s proximity to Jupiter is very unusual,” Rick Nybakken told me during an interview at JPL last year. Nybakken is Juno’s project manager. “Juno has an elliptical orbit that brings it just 3,107 miles (5,000 km) above the cloud tops. No other mission has been this close, and we’re right on top of Jupiter so to speak.”

Special instruments are studying Jupiter’s radiation belt and magnetosphere, its interior structure, and the turbulent atmosphere, as well as providing views of the planet with spectacular, close-up images.

And another great thing about this image is that it was processed by citizen scientists. Gerald Eichstaedt and John Rogers processed the image and drafted the caption, and this will be the norm for many of the JunoCam images, because it’s “the public’s camera.”

“I’m excited though for what we’re doing with the visible light camera,” said Juno Project Scientist Steve Levin, who I also interviewed at JPL. “We’re making JunoCam as much as much as we possibly can an instrument that belongs to the public. We’ll solicit the aid of the public in picking which images to take, and releasing the data in its rawest form, and allow people to go and make the images.”

Scientist Candy Hansen is leading this citizen science effort, and she uses the phrase, “science in a fishbowl,” meaning the JunoCam team is showing people what it is like to do science by allowing anyone to participate and see the data as it arrives from Juno.

Damian Peach reprocessed one of the latest images taken by Juno’s JunoCam during its 3rd close flyby of the planet on Dec. 11. The photo highlights two large ‘pearls’ or storms in Jupiter’s atmosphere. Credit: NASA/JPL-Caltech/SwRI/MSSS

You can find the raw images here, so go ahead and test out your image processing skills.

JunoCam is designed to capture remarkable pictures of Jupiter’s poles and cloud tops. Although its images will be helpful to the science team to help provide context for the spacecraft’s other instruments, it is not considered one of the mission’s science instruments. JunoCam was included on the spacecraft specifically for purposes of engaging and including the public.

The Little Red Spot is the third largest anticyclonic oval on the planet, which Earth-based observers have tracked for the last 23 years. An anticyclone is a weather phenomenon with large-scale circulation of winds around a central region of high atmospheric pressure. They rotate clockwise in the northern hemisphere, and counterclockwise in the southern hemisphere. The Little Red Spot shows very little color these days, just a pale brown smudge in the center. Back in 2006, the storm was stronger and the color changed darker and more red. Now, with the storm not quite as active, the color is very similar to the surroundings, making it difficult to see.

If you’d like to download a larger version of this processed image (need a new wallpaper?) you can find it on NASA’s website.

December 15, 2016 by Bob King

Juno Captures a Stunning Jovian ‘Pearl’

New Juno image of Jupiter taken on Dec. 11, 2016. Processed by Damian Peach

Jupiter looks beautiful in pearls! This image, taken by the JunoCam imager on NASA’s Juno spacecraft, highlights one of the eight massive storms that from a distance form a ‘string of pearls’ on Jupiter’s turbulent atmosphere. They’re counterclockwise rotating storms that appear as white ovals in the gas giant’s southern hemisphere. The larger pearl in the photo above is roughly half the size of Earth. Since 1986, these white ovals have varied in number from six to nine with eight currently visible.

Four more 'pearls' in the string of eight photographed on Dec. 10, 2016. They show up well in photos but require good seeing and at least and 8-inch telescope to see. Credit: Christopher Go — Four more ‘pearls’ photographed on Dec. 10, 2016 in the planet’s South Temperate Belt below the Great Red Spot. The moon Ganymede is at left. The show up well in photos but require good seeing and at least and 8-inch telescope to see visually. Credit: **Christopher Go**

The photos were taken during Sunday’s close flyby. At the time of closest approach — called perijove — Juno streaked about 2,580 miles (4,150 km) above the gas giant’s roiling, psychedelic cloud tops traveling about 129,000 mph or nearly 60 km per second relative to the planet. Seven of Juno’s eight science instruments collected data during the flyby. At the time the photos were taken, the spacecraft was about 15,300 miles (24,600 km) from the planet.

This is the original image sent by JunoCam on Dec. 11 and shows the 8th of the eight oval or 'pearls'in Jupiter's roiling atmosphere. Credit: NASA/JPL-Caltech/SwRI/MSSS — This is the original image sent by JunoCam on Dec. 11 and features the eighth in a string of large storms in the planet’s southern hemisphere. Credit: NASA/JPL-Caltech/SwRI/MSSS

JunoCam is a color, visible-light camera designed to capture remarkable pictures of Jupiter’s poles and cloud tops. As Juno’s eyes, it will provide a wide view, helping to provide context for the spacecraft’s other instruments. JunoCam was included on the spacecraft specifically for purposes of public engagement; although its images will be helpful to the science team, it is not considered one of the mission’s science instruments.

4-frame animation spans 24 Jovian days, or about 10 Earth days. The passage of time is accelerated by a factor of 600,000. Credit: NASA — 4-frame animation spans 24 Jovian days, or about 10 Earth days. The passage of time is accelerated by a factor of 600,000. Some of the ovals are visible as well as a variety of jets – west to east and east to west. Credit: NASA

The crazy swirls of clouds we see in the photos are composed of ammonia ice crystals organized into a dozen or so bands parallel to the equator called belts (the darker ones) and zones. The border of each is bounded by a powerful wind flow called a jet, resembling Earth’s jet streams, which alternate direction from one band to the next.

Zones are colder and mark latitudes where material is upwelling from below. Ammonia ice is thought to give the zones their lighter color. Belts in contrast indicate sinking material; their color is a bit mysterious and may be due to the presence of hydrocarbons — molecules that are made from hydrogen, carbon, and oxygen as well as exotic sulfur and phosphorus compounds.

Use this guide to help you better understand Jupiter's arrangement of belts and zones, many of which are visible in amateur telescopes. Credit: NASA/JPL/Wikipedia — Use this guide to help you better understand Jupiter’s arrangement of belts and zones, many of which are visible in amateur telescopes. Credit: NASA/JPL/Wikipedia

The pearls or storms form in windy Jovian atmosphere and can last many decades. Some eventually dissipate while others merge to form even larger storms. Unlike hurricanes, which fall apart when they blow inland from the ocean, there’s no “land” on Jupiter, so storms that get started there just keep on going. The biggest, the Great Red Spot, has been hanging around causing trouble and delight (for telescopic observers) for at least 350 years.

Juno’s next perijove pass will happen on Feb. 2, 2017.

December 9, 2016 by David Dickinson

101 Astronomical Events for 2017: A Teaser

A partial solar eclipse rising over the VAB. Image by author.

It’s that time of year again… time to look ahead at the top 101 astronomical events for the coming year.

And this year ’round, we finally took the plunge. After years of considering it, we took the next logical step in 2017 and expanded our yearly 101 Astronomical Events for the coming year into a full-fledged guide book, soon to be offered here for free download on Universe Today in the coming weeks. Hard to believe, we’ve been doing this look ahead in one form or another now since 2009.

This “blog post that takes six months to write” will be expanded into a full-fledged book. But the core idea is the same: the year in astronomy, distilled down into the very 101 best events worldwide. You will find the best occultations, bright comets, eclipses and much more. Each event will be interspersed with not only the ‘whens’ and ‘wheres,’ but fun facts, astronomical history, and heck, even a dash of astronomical poetry here and there.

It was our goal to take this beyond the realm of a simple almanac or Top 10 listicle, to something unique and special. Think of it as a cross between two classics we loved as a kid, Burnham’s Celestial Handbook and Guy Ottewell’s Astronomical Calendar, done up in as guide to the coming year in chronological format. Both references still reside on our desk, even in this age of digitization.

And we’ve incorporated reader feedback from over the years to make this forthcoming guide something special. Events will be laid out in chronological order, along with a quick-list for reference at the end. Each event is listed as a one- or two-page standalone entry, ready to be individually printed off as needed. We will also include 10 feature stories and true tales of astronomy. Some of these were culled from the Universe Today archives, while others are new astronomical tales written just for the guide.

Don’t miss 2017’s only total solar eclipse, crossing the United States! Image credit: Michael Zeiler/The Great American Eclipse.

The Best of the Best

Here’s a preview of some of the highlights for 2017:

-Solar cycle #24 begins to ebb in 2017. Are we heading towards yet another profound solar minimum?

-Brilliant Venus reaches greatest elongation in January and rules the dusk sky.

-45P/Honda-Mrkos-Pajdusakova passes 0.08 AU from Earth on February 11^th, its closest passage for the remainder of the century.

-An annular solar eclipse spanning Africa and South America occurs on February 26^th.

A sample occultation map from the book. Image credit: Occult 4.1.2.

-A fine occultation of Aldebaran by the Moon on March 5^th for North America… plus more occultations of the star worldwide during each lunation.

-A total solar eclipse spanning the contiguous United States on August 21^st.

-A complex grouping of Mercury, Venus, Mars and the Moon in mid-September.

-Saturn’s rings at their widest for the decade.

Getting wider... the changing the of Saturn's rings. Image credit and copyright: Andrew Symes (@FailedProtostar). — Getting wider… the changing face of Saturn’s rings. Image credit and copyright: Andrew Symes (@FailedProtostar).

-A fine occultation of Regulus for North America on October 15^th, with occultations of the star by the Moon during every lunation for 2017.

-Asteroid 335 Roberta occults a +3^rd magnitude star for northern Australia…

And that’s just for starters. Entries also cover greatest elongations for the inner planets and oppositions for the outer worlds, the very best asteroid occultations of bright stars, along with a brief look ahead at 2018.

Get ready for another great year of skywatching!

And as another teaser, here’s a link to a Google Calendar download of said events, complied by Chris Becke (@BeckePhysics). Thanks Chris!

October 21, 2016 by Bob King

Astronomers Think They Know Where Rosetta’s Comet Came From

In the distant past, the orbit of 67P/Churyumov-Gerasimenko extended far beyond Neptune into the refrigerated Kuiper Belt. Interactions with the gravitational giant Jupiter altered the comet's orbit over time, dragging it into the inner Solar System. Credit: Western University, Canada

Rosetta’s Comet hails from a cold, dark place. Using statistical analysis and scientific computing, astronomers at Western University in Canada have charted a path that most likely pinpoints comet 67P/Churyumov-Gerasimenko’s long-ago home in the far reaches of the Kuiper Belt, a vast region beyond Neptune home to icy asteroids and comets.

According to the new research, Rosetta’s Comet is relative newcomer to the inner parts of our Solar System, having only arrived about 10,000 years ago. Prior to that, it spent the last 4.5 billion years in cold storage in a rough-and-tumble region of the Kuiper Belt called the scattered disk.

The Kuiper Belt was named in honor of Dutch-American astronomer Gerard Kuiper, who postulated a reservoir of icy bodies beyond Neptune. The first Kuiper Belt object was discovered in 1992. We now know of more than a thousand objects there, and it's estimated it's home to more than 100,000 asteroids and comets there over 62 miles (100 km) across. Credit: JHUAPL — The Kuiper Belt was named in honor of Dutch-American astronomer Gerard Kuiper, who postulated a reservoir of icy bodies beyond Neptune. The first Kuiper Belt object was discovered in 1992. We now know of more than a thousand objects there, and it’s estimated it’s home to more than 100,000 asteroids and comets there over 62 miles (100 km) across. Credit: JHUAPL

In the Solar System’s youth, asteroids that strayed too close to Neptune were scattered by the encounter into the wild blue yonder of the disk. Their orbits still bear the scars of those long-ago encounters: they’re often highly-elongated (shaped like a cigar) and tilted willy-nilly from the ecliptic plane up to 40°. Because their orbits can take them hundreds of Earth-Sun distances into the deeps of space, scattered disk objects are among the coldest places in the Solar System with surface temperatures around 50° above absolute zero. Ices that glommed together to form 67P at its birth are little changed today. Primordial stuff.

Watch how Rosetta’s Comet’s orbit has evolved since the comet’s formation

There are two basic comet groups. Most comets reside in the cavernous Oort Cloud, a roughly spherical-shaped region of space between 10,000 and 100,000 AU (astronomical unit = one Earth-Sun distance) from the Sun. The other major group, the Jupiter-family comets, owes its allegiance to the powerful gravity of the giant planet Jupiter. These comets race around the Sun with periods of less than 20 years. It’s thought they originate from collisions betwixt rocky-icy asteroids in the Kuiper Belt.

Fragments flung from the collisions are perturbed by Neptune into long, cigar-shaped orbits that bring them near Jupiter, which ropes them like calves with its insatiable gravity and re-settles them into short-period orbits.

Comet 67P/Churyumov-Gerasimenko is a Jupiter-family comet. Its 6.5 year journey around the Sun takes it from just beyond the orbit of Jupiter at its most distant, to between the orbits of Earth and Mars at its closest. Credit: ESA with labels by the author — Comet 67P/Churyumov-Gerasimenko is a Jupiter-family comet. Its 6.5 year journey around the Sun takes it from just beyond the orbit of Jupiter at its most distant to between the orbits of Earth and Mars at its closest. Credit: ESA with labels by the author

Mattia Galiazzo and solar system expert Paul Wiegert, both at Western University, showed that in transit, Rosetta’s Comet likely spent millions of years in the scattered disk at about twice the distance of Neptune. The fact that it’s now a Jupiter family comet hints of a possible long-ago collision followed by gravitational interactions with Neptune and Jupiter before finally becoming an inner Solar System homebody going around the Sun every 6.45 years.

By such long paths do we arrive at our present circumstances.

October 20, 2016 by Evan Gough

No, There Won’t Be 15 Days of Darkness in November. It’s Another Stupid Hoax.

Venus and Jupiter at dusk over Australia's Outback on June 27, 2015. Credit: Joseph Brimacombe

The internet is great, isn’t it?

You can post anything you want on the internet, and if people like the sound of it, they spread it. It doesn’t make any difference if it’s true or not. We’re not born fact checkers and skeptics, are we?

Pretty soon, before you know it, it’s gone viral. Then it becomes its own sensation, and people who don’t even believe it start reporting it. Never is this more true than with hoaxes.

The latest hoax is the “15 Days of Darkness in November” thing that’s going around. Everyone’s on the bandwagon.

The 15 days hoax is not new. It made an appearance last year, and was thoroughly debunked. And of course, there wasn’t 15 day of darkness last year, was there? (Unless NASA covered it up!)

It’s here again this year, and will be debunked again, and will probably be here next year, too.

The whole thing started at a site that will remain linkless, and caught on from there. This is what the site reported:

“NASA has confirmed that the Earth will experience 15 days of total darkness between November 15 and November 29, 2015. The event, according to NASA, hasn’t occurred in over 1 Million years.”

Of course, NASA never said any such thing.

Here is supposedly what will happen to cause this calamity. Try and follow along with the nonsensical foolishness.

During the conjunction between Venus and Jupiter on October 26, light from Venus would cause gases in Jupiter to heat up. The heated gasses will cause a large amount of hydrogen to be released into space. The gases will reach the Sun and trigger a massive explosion on the surface of the star, heating it to 9,000 degrees Kelvin. The heat of the explosion would then cause the Sun to emit a blue color.
The dull blue color will last for 15 days during which the Earth will be thrown into darkness.

Where to begin? Let’s start with conjunctions.

Conjunctions are mostly just visual phenomena. The fact that two things in the sky look closer together from our point of view on Earth doesn’t mean that they’re that close together. In fact, even when Jupiter and Venus are in conjunction, they can still be over 800 million km apart. For perspective, the Sun and the Earth are about 150 million km apart.

So, as the hoax goes, at that great distance, light from Venus will cause gases on Jupiter to heat up. News Flash: the light from the Sun is far more intense than light from Venus could ever be, and it doesn’t heat up the gases on Jupiter. In fact, any light from Venus that makes it to Jupiter is just reflected sunlight anyway.

The Moon and this dead tree are in conjunction. This will cause the Martian Pyramids to vibrate harmonically. These vibrations will shake the walls of the movie studio where the Moon landing was faked, causing it to collapse. Image: Evan Gough

The hoax gets more outrageous as it goes along. These supposed heated gases then escape from Jupiter into space, and head for the Sun. But Jupiter is enormous and has enormous gravitational pull. How are any gases going to escape Jupiter’s overpowering gravity? Answer: they can’t and they won’t.

Then, these gases supposedly strike the Sun, and trigger a massive explosion on the Sun’s surface, which turn the Sun blue and plunges the Earth into darkness. Not blueness, which I could understand, but darkness.

This is absurd, of course. The Sun dominates the planets in a one-way relationship, and nothing the planets ever do could change that. No escaped gases from Jupiter would ever strike the Sun.

Jupiter is puny and insignificant compared to the Sun. And it's also hundreds of millions of kilometers away. How is a puny puff of hydrogen from Jupiter supposed to darken the Sun? Image: NASA/SDO — Jupiter is puny and insignificant compared to the Sun. And it’s also hundreds of millions of kilometers away. How is a puny puff of hydrogen from Jupiter supposed to darken the Sun? Image: NASA/SDO

Nothing Jupiter does can affect the Sun. Jupiter is, on average, 778 million km from the Sun. Jupiter could change places with Venus, and the Sun would keep shining normally. Jupiter could explode completely and the Sun would go on shining normally. Jupiter could put on a big red nose and some clown shoes, and the Sun would remain unaffected.

The Sun is a giant atom-crushing machine 1000 times more massive than Jupiter. The massive wall of energy and solar wind that comes from the Sun slams into Jupiter, and completely overwhelms anything Jupiter can do to the Sun. It’s just the way it is. It’s just the way it will always be.

Like the faked Moon landing hoax, and the Nibiru/Planet X hoax, this 15 days of darkness meme just keeps coming around. There may be no end to it.

It’s annoying, for sure, but maybe there’s a silver lining. Maybe some people reading about this supposed calamity will enter the word “conjunction” into a search engine, and begin their own personal journey of learning how the universe works.

We can hope so, can’t we?

October 5, 2016October 5, 2016 by David Dickinson

Seeing Double: Jupiter Returns at Dawn

Missing Jove? The largest planet in our solar system is currently on the far side of the Sun and just passed solar conjunction on September 26^th, 2016. October now sees Jupiter slowly return to the dawn sky. Follow that gas giant, as an interesting set of double shadow transits transpires in late October leading in to early November.

This particular cycle of double shadow transits involves the large Jovian moons of Europa and Ganymede.

The scene on October 24th at 23:55 UT. Image credit: Created using Starry Night Education software.

Europa and Ganymede double shadow transit season begins later this month, as both cast shadows on the Jovian cloud tops. This series of simultaneous shadow transits runs from October 17^th to November 8^th, and includes four weekly events.

The inner three large moons Io, Europa and Ganymede are in a 4:2:1 resonance. Europa orbits Jove once every 3.6 days and makes two circuits for Ganymede’s one. This means there’s a double shadow transit once every week in the current season:

The double shadow transit season of 2016. Created by author.

When can you first spy Jupiter, post solar conjunction? Catching this particular series of double shadow transits is challenging this time around, owing to the planet’s position low in the dawn twilight. The first event on October 17^th starts with Jupiter just 16 degrees west of the Sun, and the cycle ends with Jove 38 degrees west of the Sun on November 8^th.

Keep in mind, it is possible to track Jupiter up in to the daytime sky, post sunrise. To do this, you’ll need a ‘scope with a solid equatorial mount and good sidereal tracking. The trick is to lock on to Jupiter before sunrise and track it up in to the dawn sky. Be sure to physically block that dazzling rising Sun out of view behind a hill or building, and NEVER aim your telescope at the Sun!

Using this method opens up the possibility of nabbing a given double shadow event to longitudes due east of the quoted locales above.

The waning crescent Moon also passes 1.4 degrees NNE of Jupiter on October 28^th, offering another chance to spy the gas giant in the dawn sky, using the nearby crescent Moon as a guide.

The Moon and Jupiter in the daytime skies on Novemebr. — The Moon and Jupiter in the daytime skies on October 28th. Image credit: Stellarium.

And another interesting pairing is coming right up on the morning of Tuesday, October 11^th, when Mercury passes just 0.8 degrees (48′) NNE of Jupiter. Both are only 12 degrees west of the Sun at closest approach, which occurs around 10:00 UT. Still, both will appear as an interesting pseudo-double star, with Mercury shining at magnitude -1.1 and Jupiter only half a magnitude fainter at -1.6.

You can even see Jupiter coming off of solar conjunction and headed toward dawn skies courtesy of SOHO’s LASCO C3 camera:

Jupiter (arrowed) exiting the 15 degree wide field of view of SOHO's LASCO C3 camera on October 5th. Image credit: NASA/ESA/SOHO. — Jupiter (arrowed) exiting the 15 degree wide field of view of SOHO’s LASCO C3 camera on October 5th. Image credit: NASA/ESA/SOHO.

Callisto, the outermost large moon of Jupiter, ceased casting its shadow on Jupiter earlier this year on September 1^st 2016. Callisto is the only large moon that can ‘miss’ the gas giant’s cloud tops. Callisto must be involved for a triple shadow transit to occur, and the moon resumes regularly casting its shadow on Jove on December 4th, 2019.

Callisto can also experience total solar eclipses similar to those seen from the Earth during the mutual eclipse season for Jupiter’s moons, albeit shorter in duration:

And don ‘t forget: we’ve got a spacecraft currently exploring Jupiter for the next year and a half: NASA’s very own Juno.

Be sure to check out the Jovian action over the next month, gracing a dawn sky near you.