Posted on 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

Posted on 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.

Reprocessed image taken by the 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

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

Posted on by Matt Williams

Juno Buzzes Jupiter a mere 4,300 Km’s above the Cloud Tops

Illustration of NASA's Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA's Jet Propulsion Laboratory. Credit: NASA/Lockheed Martin

On July 4th, 2016, NASA’s Juno spacecraft made history when it became the second mission to establish orbit around Jupiter – the previous being the Galileo spacecraft, which orbited the planet from 1995 to 2003. Since that time, it has circled the massive gas giant three times, collecting data on the gas giant’s composition, interior and gravity field.

This past Thursday, February 1st, the mission conducted its fourth orbit of the planet. In the process, the spacecraft collected more vital data on the gas giant and snapped several dozen pictures. And in what is has been a first for a space mission, NASA will once again be asking the public what features they would like to see photographed during Juno’s next pass.

Juno made its closest pass (what is known as perijove) to Jupiter at precisely 1257 GMT (7:57 a.m. EST), passing the cloud tops at a distance of 4,300 km (2,670 mi) and traveling at a velocity of about 208,000 km/h (129,300 mph) relative to the gas giant. Using its suite of instruments, it scanned Jupiter’s atmosphere, gathered data on its radiation and plasma, and began returning this information to Earth.

Processed image taken on Dec. 11, 2016, at 9:27 a.m. PST (12:27 p.m. EST) by the NASA Juno spacecraft, as it performed its third close flyby of Jupiter. Credits: NASA/JPL-Caltech/SwRI/MSSS/Eric Jorgensen

And during this latest pass, the JunoCam snapped several dozen more pictures. During two of its three previous perijove maneuvers, this instruments captured some of the most breathtaking photographs of Jupiter’s clouds to date (like the one seen above). Once they were transmitted back to Earth and made available to the public, “citizen scientists” were able to download and process them at their leisure.

And with this latest pass complete, the public is once again being encouraged to vote on what features they want to see photographed during the next pass. As Candy Hansen, the Juno mission’s co-investigator from the Planetary Science Institute, stated shortly before Juno made its fourth perijovian maneuver:

“The pictures JunoCam can take depict a narrow swath of territory the spacecraft flies over, so the points of interest imaged can provide a great amount of detail. They play a vital role in helping the Juno science team establish what is going on in Jupiter’s atmosphere at any moment. We are looking forward to seeing what people from outside the science team think is important.”

This has all been part of a first-ever effort on behalf of NASA to get the public involved in what kinds of images are to be taken. According to NASA, this is to become a regular feature of the Juno mission, with a  new voting page being created for each upcoming flyby. The next perijovian maneuver will take place on March 27th, 2017, coinciding with the Juno spacecraft’s 53.4-day orbital period.

False color view of Jupiter’s polar haze, created by citizen scientist Gerald Eichstädt using data from the JunoCam instrument. Credit: NASA/JPL-Caltech/SwRI/MSSS/Eric Jorgensen

Originally, the mission planners had hoped to narrow Juno’s orbital period down to 14 days, which would have been accomplished by having the craft fire its main engine while at perijove. However, two weeks before the engine burn was scheduled to take place (Oct. 19th, 2016), ground controllers noticed a problem with two of the engine’s check valves – which are part of the spacecraft’s fuel pressurization system.

As Juno project manager Rick Nybakken said at the time:

“Telemetry indicates that two helium check valves that play an important role in the firing of the spacecraft’s main engine did not operate as expected during a command sequence that was initiated yesterday. The valves should have opened in a few seconds, but it took several minutes. We need to better understand this issue before moving forward with a burn of the main engine.”

Because of this technical issue, the mission leaders chose to postpone the engine burn so they could check the craft’s instruments to get a better understanding of why it happened. The Juno team was hoping to use the third orbit of the spacecraft to study the problem, but this was interrupted when a software performance monitor induced a reboot of the spacecraft’s onboard computer.

To accomplish its science objectives, Juno is orbiting Jupiter’s poles and passing very close to the planet, avoiding the most powerful (and hazardous) radiation belts in the process. Credit: NASA/JPL-Caltech

Because of this, the spacecraft went into safe mode during its third flyby, which prevented them from gathering data on the engine valve problem. On Oct. 24th, the mission controllers managed to get the craft to exit safe mode and performed a trim maneuver in preparation for its next flyby. But the mystery of why the engine valves failed to open remains, and the mission team is still unable to resolve the problem.

Thus, the decision to fire the main engine (thereby shortening its orbital period) has been postponed until they get it back online. But as Scott Bolton – the Associate Director of R&D at the Southwest Research Institute (SwRI) and Juno’s Principal Investigator – has emphasized in the past:

“It is important to note that the orbital period does not affect the quality of the science that takes place during one of Juno’s close flybys of Jupiter. The mission is very flexible that way. The data we collected during our first flyby on August 27th was a revelation, and I fully anticipate a similar result from Juno’s October 19th flyby.”

In the meantime, the Juno science team is still analyzing data from all previous Jupiter flybys. During each pass, the spacecraft and its instruments peer beneath Jupiter’s dense cloud cover to study its auroras, its magnetic field, and to learn more about the planet’s structure, composition, and formation. And with the public’s help, it is also providing some of the clearest and most detailed imagery of the gas giant to date.

Further Reading: NASA

 

Posted on by Matt Williams

What Can We Expect From Juno’s Return To Jupiter?

Illustration of NASA's Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA's Jet Propulsion Laboratory. Credit: NASA/Lockheed Martin

The Juno spacecraft made history on July 4th, 2016, when it became the second spacecraft in history to achieve orbit around Jupiter for the sake of a long-term mission. Following in the footsteps of the Galileo mission, the probe will spend the next 20 months gathering data on Jupiter’s atmosphere, clouds, interior and gravitational and magnetic fields, before purposefully crashing into the planet.

And on Saturday, August 27th, Juno will be making history once again. According to NASA, at precisely 12:51 UTC (5:51 a.m. PDT, 8:51 a.m. EDT) the spacecraft will be passing closer to the cloud tops of Jupiter than at any point in its main mission. And while the probe is expected to make 35 more close flybys of the gas giant before its mission ends in February of 2018, this particular one is expected to be especially revealing.

For one, it will be the first time that the probe has all of its scientific instruments online and surveying Jupiter’s atmosphere as it swings past. And during the flyby, the probe will be passing Jupiter’s cloud tops at a distance of 4,200 kilometers (2,500 miles) – closer than it will ever get again – while traveling at a speed of 208,000 km/hour (130,000 mph).

This annotated color view of Jupiter and its four largest moons -- Io, Europa, Ganymede and Callisto -- was taken by the JunoCam camera on NASA's Juno spacecraft on June 21, 2016, at a distance of 6.8 million miles (10.9 million kilometers) from Jupiter. Image credit: NASA/JPL-Caltech/MSSS
This annotated color view of Jupiter and its four largest moons — Io, Europa, Ganymede and Callisto — was taken by the JunoCam camera on NASA’s Juno spacecraft on June 21, 2016, at a distance of 6.8 million miles (10.9 million kilometers) from Jupiter. Image credit: NASA/JPL-Caltech/MSSS

This will not only be the closest approach to Jupiter made by any probe, but it will pass over Jupiter’s poles, which will give Juno the opportunity to get a look at some never-before-seen things. These will include infrared and microwave readings taken by Juno’s suite of eight instruments, but also some choice photographs.

Yes, in addition to its sensor package, Juno‘s visible light imager (aka. JunoCam) will also be active and taking some close-up pictures of the atmosphere and poles. While the scientific information is expected to keep NASA scientists occupied for some time to come, the JunoCam images are expected to be released later next week.

According to NASA, these images will be the highest resolution photos of the Jovian atmosphere ever taken, not to mention the first glimpse of Jupiter’s north and south poles ever. As Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio, said in a NASA press release:

“This is the first time we will be close to Jupiter since we entered orbit on July 4. Back then we turned all our instruments off to focus on the rocket burn to get Juno into orbit around Jupiter. Since then, we have checked Juno from stem to stern and back again. We still have more testing to do, but we are confident that everything is working great, so for this upcoming flyby Juno’s eyes and ears, our science instruments, will all be open… This is our first opportunity to really take a close-up look at the king of our Solar System and begin to figure out how he works.”

NASA's Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL
NASA’s Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL

Ever since the Juno spacecraft launched on Aug. 5th, 2011, from Cape Canaveral, Florida, scientists and astronomers have been waiting for the day when it would start sending back information on the Solar System’s greatest planet. By examining the atmosphere, interior, and magnetic environment of the gas giant, scientists hope to be able to answer burning questions about the history of the planet’s formation.

For example, Jupiter’s interior structure and composition, as well as what drives its magnetic field, are still the subject of debate. In addition, there are some unanswered questions about when and where the planet formed. While it may have formed in its current orbit, some evidence suggests that it could have formed farther from the sun before migrating inward. All of these questions, it is hoped, are things the Juno mission will answer.

In so doing, scientists hope to be able to shed some additional light on the history of the Solar System as well. Like the other gas giants, it was assembled during the early phases, before our Sun had the chance to absorb or blow away the light gases in the huge cloud from which both were born. As such, Jupiter’s composition could tell us much about the early Solar System.

And this Saturday, the probe will be gathering what could prove to be the most crucial information its mission will produce. And of course, if all goes well, it will be taking the most detailed pictures of the Jovian giant to date! Godspeed, little Juno. You be careful out there!

Further Reading: NASA

Posted on by Matt Williams

Jovians Distressed At Strange, Tiny & Silent Creatures Aboard Spacecraft

The three Lego figures inside: Galileo, Juno and Jupiter. Source: NASA

Given its historic importance – being just the second spacecraft to conduct a long-term mission to Jupiter – NASA was sure to outfit the Juno probe with some high-end memorabilia. These include the Galileo commemorative plaque*, which shows Galileo’s face and the words he wrote when he first observed Jupiter’s four largest moons in 1610 (known today as the Galilean Moons).

In addition, three commemorative figures (each measuring 4 cm high) were created especially for the mission. Created by Lego, these figurines depict the Roman god Jupiter, his wife Juno, and the astronomer Galileo Galilei – each holding an identifying object. Constructed from aluminum so they could withstand the trip and the radiation of the gas giant, these figures arrived with the probe around Jupiter on Monday, July 4th.

Much like the Juno spacecraft that is ferrying them, these figurines have spent the past 5 years in space and traversing the 869 million kilometers that lie between Earth from Jupiter. As part of Lego’s “Build Your Future” campaign,  the trio are part of an educational outreach program to inspire kids around the world to learn about science and technology.

A key part of this effort is the Building Challenge launched by Lego to raise awareness about space exploration. For this challenge, participants are asked to build their vision of the future of space exploration using Lego bricks, take pictures of their creation, and then upload them to the Lego website’s “Mission to Space” gallery. The winning creations will be featured on LEGO.com and the Gallery homepage.

NASA's Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL
NASA’s Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL

In addition, Lego’s website has new content that encourages children to learn more about the Solar System. As they state on the webpage:

“Have you ever wondered what it would be like if you could visit other planets and travel through space? Well, here’s your chance to go on a mission to Space through a partnership between NASA and LEGO Group! Pack your space lunch, and get ready to fly the International Space Station, pass the Moon, to Mars and Jupiter! Learn fun facts about our solar system, play quizzes, and get a taste of life as an astronaut and space pioneer! Round off the trip by entering an out-of-this-world building challenge.”

True to their mythological roots, the figurine of Jupiter (the Roman equivalent of Zeus) is holding a lightning bolt. Juno, his wife, is holding a magnifying glass, which represents her ability to see through the clouds that Jupiter surrounded himself with. And Galileo, the famed astronomer who was the first to view Jupiter’s moons, holds his famed telescope and an orb representing Jupiter.

These three figurines are the closest thing the Juno spacecraft has to a crew. During the next two years, they will be with the probe as it orbits Jupiter a total of 37 times, conducting surveys of Jupiter’s atmosphere, interior, magnetosphere, and gravitational field. When the mission is over, they will deorbit with the probe, crashing into Jupiter’s atmosphere to prevent any contamination of Jupiter’s moons.

Three LEGO figurines representing the Roman god Jupiter, his wife Juno and Galileo Galilei are shown here aboard the Juno spacecraft. Credits: NASA/JPL-Caltech/KSC
Three LEGO figurines representing the Roman god Jupiter, his wife Juno and Galileo Galilei are shown here aboard the Juno spacecraft. Credits: NASA/JPL-Caltech/KSC

Over the course of the past three days, numerous memes have popped up across the internet, claiming that: “When Galileo first spotted Jupiter’s largest moons, he named them after Jove’s (Zeus’) mistresses. Now, a probe named after his wife will arrive in the system, thus fulfilling a joke astronomers have been setting up for the past 400 years!” – I’m paraphrasing, of course!

Nevertheless, the observation is an apt one. And to make this witty statement complete, all those figures who had a hand in lending Jupiter the cultural significant it has (be they historical or mythological) will be represented as Juno tries to unveil Jupiter’s mysteries. Sure, those likenesses are just 4 cm in height, and they are built out of aluminum instead of marble, but it’s the thought that counts!

*The Galileo commemorative plague contains script written in Italian by Galileo’s own hand. It reads:

“On the 11th it was in this formation, and the star closest to Jupiter was half the size than the other and very close to the other so that during the previous nights all of the three observed stars looked of the same dimension and among them equally afar; so that it is evident that around Jupiter there are three moving stars invisible till this time to everyone.”

And be sure to enjoy this video of NASA’s Juno team celebrating the probe’s arrival at Jupiter:

Further Reading: NASA June, Lego

Posted on by Matt Williams

Very Large Telescope Images Of Jupiter Prepare Us For Juno Arrival

In preparation for the arrival of Juno, the ESO's released stunning IR images of Jupiter, taken by the VLT. Credit: ESO
In preparation for the arrival of Juno, the ESO's released stunning IR images of Jupiter, taken by the VLT. Credit: ESO

Launching back in 2011, NASA’s Juno mission has spent the past five years traversing the gulf that lies between Earth and Jupiter. When it arrives (in just a few days time!), it will be the second long-term mission to the gas giant in history. And in the process, it will obtain information about its composition, weather patterns, magnetic and gravitational fields, and history of formation.

With just days to go before this historic rendezvous takes place, the European Southern Observatory is taking the opportunity to release some spectacular infrared images of Jupiter. Taken with the Very Large Telescope (VLT), these images are part of a campaign to create high-resolutions maps of the planet, and provide a preview of the work that Juno will be doing in the coming months.

Using the VTL Imager and Spectrometer for mid-Infrared (VISIR) instrument, the ESO team – led by Dr. Leigh Fletcher of the University of Leicester – hopes that their efforts to map the planet will improve our understanding of Jupiter’s atmosphere. Naturally, with the upcoming arrival of Juno, some may wonder if these efforts are necessary.

The Very Large Telescoping Interferometer firing it's adaptive optics laser. Credit: ESO/G. Hüdepohl
Using images obtained by the Very Large Telescope, an ESO team managed to obtain detailed IR images of Jupiter’s atmosphere. Credit: ESO/G. Hüdepohl

After all, ground-based telescopes like the VLT are forced to contend with limitations that space-based probes are not. These include interference from our constantly-shifting atmosphere, not to mention the distances between Earth and the object in question. But in truth, the Juno mission and ground-based campaigns like these are often highly complimentary.

For one, in the past few months, while Juno was nearing in on its destination, Jupiter’s atmosphere has undergone some significant shifts. Mapping these is important to Juno‘s upcoming arrival, at which point it will be attempting to peer beneath Jupiter’s thick clouds to discern what is going on beneath. In short, the more we know about Jupiter’s shifting atmosphere, the easier it will be to interpret the Juno data.

As Dr. Fletcher described the significance of his team’s efforts:

“These maps will help set the scene for what Juno will witness in the coming months. Observations at different wavelengths across the infrared spectrum allow us to piece together a three-dimensional picture of how energy and material are transported upwards through the atmosphere.”

Like all ground-based efforts, the ESO campaign – which has involved the use of several telescopes based in Hawaii and Chile, as well as contributions from amateur astronomers around the world – faced some serious challenges (like the aforementioned interference). However, the team used a technique known as “lucky imaging” to take the breathtaking snapshots of Jupiter’s turbulent atmosphere.

This view compares a lucky imaging view of Jupiter from VISIR (left) at infrared wavelengths with a very sharp amateur image in visible light from about the same time (right). Credit: ESO/L.N. Fletcher/Damian Peach
This view compares a lucky imaging view of Jupiter from VISIR (left) at infrared wavelengths with a very sharp amateur image in visible light from about the same time (right). Credit: ESO/L.N. Fletcher/Damian Peach

What this comes down to is taking many sequences of images with very short exposures, thus producing thousands of individual frames. The lucky frames, those where the image are least affected by the atmosphere’s turbulence, are then selected while the rest discarded. These selected frames are aligned and combined to produce final pictures, like the one shown above.

In addition to providing information that would be of use to the Juno mission, the ESO’s campaign has value that extends beyond the space-based mission. As Glenn Orton, the leader of ESO’s ground-based campaign, explained, observations like these are valuable because they help to advance our understanding of planets as a whole, and provide opportunities for astronomers from all over the world to collaborate.

“The combined efforts of an international team of amateur and professional astronomers have provided us with an incredibly rich dataset over the past eight months,” he said. “Together with the new results from Juno, the VISIR dataset in particular will allow researchers to characterize Jupiter’s global thermal structure, cloud cover and distribution of gaseous species.”

The Juno probe will be arriving at Jupiter this coming Monday, July 4th. Once there, it will spend the next two years orbiting the gas giant, sending information back to Earth that will help to advance our understanding of not only Jupiter, but the history of the Solar System as well.

Further Reading: ESO

Posted on by Matt Williams

Io, Jupiter’s Volcanic Moon

This global view of Jupiter's moon, Io, was obtained during the tenth orbit of Jupiter by NASA's Galileo spacecraft. Credit: NASA
This global view of Jupiter's moon, Io, was obtained during the tenth orbit of Jupiter by NASA's Galileo spacecraft. Credit: NASA

Exploring the Solar System is like peeling an onion. With every layer removed, one finds fresh mysteries to ponder over, each one more confounding than the last. And this is certainly the case when it comes to Jupiter’s system of moons, particularly its four largest – Io, Europa, Ganymede and Callisto. Known as the Galilean Moons, in honor of their founder, these moons possess enough natural wonders to keep scientists busy for centuries.

As Jupiter’s innermost moon, it is also the fourth-largest moon in the Solar System, has the highest density of any known moon, and is the driest known object in the Solar System. It is also one of only four known bodies that experiences active volcanism and – with over 400 active volcanoes – it is the most geologically active body in the Solar System.

Continue reading “Io, Jupiter’s Volcanic Moon”

Posted on by Matt Williams

What is the Biggest Planet in the Solar System?

Jupiter and Io
Io and Jupiter as seen by New Horizons during its 2008 flyby. (Credit: NASA/Johns Hopkins University APL/SWRI).

Ever since the invention of the telescope four hundred years ago, astronomers have been fascinated by the gas giant of Jupiter. Between it’s constant, swirling clouds, its many, many moons, and its Giant Red Spot, there are many things about this planet that are both delightful and fascinating.

But perhaps the most impressive feature about Jupiter is its sheer size. In terms of mass, volume, and surface area, Jupiter is the biggest planet in our Solar System by a wide margin. But just what makes Jupiter so massive, and what else do we know about it?

Size and Mass:

Jupiter’s mass, volume, surface area and mean circumference are 1.8981 x 1027 kg, 1.43128 x 1015 km3, 6.1419 x 1010 km2, and 4.39264 x 105 km respectively. To put that in perspective, Jupiter diameter is roughly 11 times that of Earth, and 2.5 the mass of all the other planets in the Solar System combined.

But, being a gas giant, Jupiter has a relatively low density – 1.326 g/cm3 – which is less than one quarter of Earth’s. This means that while Jupiter’s volume is equivalent to about 1,321 Earths, it is only 318 times as massive. The low density is one way scientists are able to determine that it is made mostly of gases, though the debate still rages on what exists at its core (see below).

Composition:

Jupiter is composed primarily of gaseous and liquid matter. It is the largest of the gas giants, and like them, is divided between a gaseous outer atmosphere and an interior that is made up of denser materials. Its upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume of gas molecules, and approx. 75% hydrogen and 24% helium by mass, with the remaining one percent consisting of other elements.

This cut-away illustrates a model of the interior of Jupiter, with a rocky core overlaid by a deep layer of liquid metallic hydrogen. Credit: Kelvinsong/Wikimedia Commons
This cut-away illustrates a model of the interior of Jupiter, with a rocky core overlaid by a deep layer of liquid metallic hydrogen. Credit: Kelvinsong/Wikimedia Commons

The atmosphere contains trace amounts of methane, water vapor, ammonia, and silicon-based compounds as well as trace amounts of benzene and other hydrocarbons. There are also traces of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, and sulfur. Crystals of frozen ammonia have also been observed in the outermost layer of the atmosphere.

The interior contains denser materials, such that the distribution is roughly 71% hydrogen, 24% helium and 5% other elements by mass. It is believed that Jupiter’s core is a dense mix of elements – a surrounding layer of liquid metallic hydrogen with some helium, and an outer layer predominantly of molecular hydrogen. The core has also been described as rocky, but this remains unknown as well.

In 1997, the existence of the core was suggested by gravitational measurements, indicating a mass of from 12 to 45 times the Earth’s mass, or roughly 4%–14% of the total mass of Jupiter. The presence of a core is also supported by models of planetary formation that indicate how a rocky or icy core would have been necessary at some point in the planet’s history in order to collect its bulk of hydrogen and helium from the protosolar nebula.

However, it is possible that this core has since shrunk due to convection currents of hot, liquid, metallic hydrogen mixing with the molten core. This core may even be absent now, but a detailed analysis is needed before this can be confirmed. The Juno mission, which launched in August 2011, is expected to provide some insight into these questions, and thereby make progress on the problem of the core.

The temperature and pressure inside Jupiter increase steadily toward the core. At the “surface”, the pressure and temperature are believed to be 10 bars and 340 K (67 °C, 152 °F). At the “phase transition” region, where hydrogen becomes metallic, it is believed the temperature is 10,000 K (9,700 °C; 17,500 °F) and the pressure is 200 GPa. The temperature at the core boundary is estimated to be 36,000 K (35,700 °C; 64,300 °F) and the interior pressure at roughly 3,000–4,500 GPa.

Moons:

The Jovian system currently includes 67 known moons. The four largest are known as the Galilean Moons, which are named after their discoverer, Galileo Galilei. They include: Io, the most volcanically active body in our Solar System; Europa, which is suspected of having a massive subsurface ocean; Ganymede, the largest moon in our Solar System; and Callisto, which is also thought to have a subsurface ocean and features some of the oldest surface material in the Solar System.

Then there’s the Inner Group (or Amalthea group), which is made up of four small moons that have diameters of less than 200 km, orbit at radii less than 200,000 km, and have orbital inclinations of less than half a degree. This groups includes the moons of Metis, Adrastea, Amalthea, and Thebe. Along with a number of as-yet-unseen inner moonlets, these moons replenish and maintain Jupiter’s faint ring system.

Jupiter also has an array of Irregular Satellites, which are substantially smaller and have more distant and eccentric orbits than the others. These moons are broken down into families that have similarities in orbit and composition, and are believed to be largely the result of collisions from large objects that were captured by Jupiter’s gravity.

Illustration of Jupiter and the Galilean satellites. Credit: NASA
Illustration of Jupiter and the Galilean satellites. Credit: NASA

Interesting Facts:

Much like Earth, Jupiter experiences auroras near its northern and southern poles. But on Jupiter, the auroral activity is much more intense and rarely ever stops. The intense radiation, Jupiter’s magnetic field, and the abundance of material from Io’s volcanoes that react with Jupiter’s ionosphere creates a light show that is truly spectacular.

Jupiter also has a violent atmosphere. Winds in the clouds can reach speeds of up to 620 kph (385 mph). Storms form within hours and can become thousands of km in diameter overnight. One storm, the Great Red Spot, has been raging since at least the late 1600s. The storm has been shrinking and expanding throughout its history; but in 2012, it was suggested that the Giant Red Spot might eventually disappear.

The discovery of exoplanets has revealed that planets can get even bigger than Jupiter. In fact, the number of “Super Jupiters” observed by the Kepler space probe (as well as ground-based telescopes) in the past few years has been staggering. In fact, as of 2015, more than 300 such planets have been identified.

Notable examples include PSR B1620-26 b (Methuselah), which was the first super-Jupiter to be observed (in 2003). At 12.7 billion years of age, it is also the third oldest known planet in the universe. There’s also HD 80606 b (Niobe), which has the most eccentric orbit of any known planet, and 2M1207b (Lerna), which orbits the brown dwarf Fomalhaut b (Illion).

Scientist theorize that a gas gain could get 15 times the size of Jupiter before it began deuterium fusion, making it a brown dwarf star. Good thing too, since the last thing the Solar System needs if for Jupiter to go nova!

Jupiter was appropriately named by the ancient Romans, who chose to name after the king of the Gods (Jupiter, or Jove). The more we have come to know and understand about this most-massive of Solar planets, the more deserving of this name it appears.

If you’re wondering, here’s how big planets can get with a lot of mass, and here’s what is the biggest star in the Universe. And here’s the 2nd largest planet in the Solar System.

Here’s another article about the which is the largest planet in the Solar System, and here’s what’s the smallest planet in the Solar System.

We have recorded a whole series of podcasts about the Solar System at Astronomy Cast. Check them out here.

Sources:

Posted on by Ken Kremer

NASA Gives ‘GO’ for Mission to Alien Ocean World at Jupiter Moon Europa

Artist's concept of NASA mission streaking over Europa. Credit: NASA/JPL

Artist’s concept of NASA mission streaking over ocean world of Europa. Credit: NASA/JPL
Story updated[/caption]

At long last NASA is heading back to Jupiter’s mysterious moon Europa and doing so in a big way – because scientists believe it harbors an alien ocean of water beneath an icy crust and therefore is “one of the most promising places in the solar system to search for signs of present-day life” beyond Earth.

Top NASA officials have now formally and officially green lighted the Europa ocean world robotic mission and given it the “GO” to move from early conceptual studies into development of the interplanetary spacecraft and mission hardware, to search for the chemical constituents of life.

“Today we’re taking an exciting step from concept to mission, in our quest to find signs of life beyond Earth,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington, in a NASA statement.

The goal is to investigate the habitability of Europa’s subsurface ocean, determine if it possesses the ingredients for life and advance our understanding of “Are we Alone?”

“Observations of Europa have provided us with tantalizing clues over the last two decades, and the time has come to seek answers to one of humanity’s most profound questions,” said Grunsfeld.

Water is a prerequisite for life as we know it.

“We know that on Earth everywhere there is water we find life,” says Robert Pappalardo, Europa mission project scientist.

“Therefore Europa is the most likely place to find life in our solar system today because we think there is a liquid water ocean beneath its surface.”

Video caption: Alien Ocean: NASA’s Mission to Europa. Could a liquid water ocean beneath the surface of Jupiter’s moon Europa have the ingredients to support life? Here’s how NASA’s mission to Europa would find out. Credit: NASA

After a thorough review of the mission concept, managers agreed that it “successfully completed its first major review by the agency and now is entering the development phase known as formulation

“It’s a great day for science,” said Joan Salute, Europa program executive at NASA Headquarters in Washington.

“We are thrilled to pass the first major milestone in the lifecycle of a mission that will ultimately inform us on the habitability of Europa.”

In a major milestone leading up to this mission development approval, NASA managers recently announced the selection of the nine science instruments that will fly on the agency’s long awaited planetary science mission to this intriguing world that many scientists suspect could support life, as I reported here last month.

“We are trying to answer big questions. Are we alone,” said Grunsfeld at the May 26 media briefing.

“The young surface seems to be in contact with an undersea ocean.”

This 12-frame mosaic provides the highest resolution view ever obtained of the side of Jupiter's moon Europa that faces the giant planet. It was obtained on Nov. 25, 1999 by the camera onboard the Galileo spacecraft, a past NASA mission to Jupiter and its moons. Credit: NASA/JPL/University of Arizona
This 12-frame mosaic provides the highest resolution view ever obtained of the side of Jupiter’s moon Europa that faces the giant planet. It was obtained on Nov. 25, 1999 by the camera onboard the Galileo spacecraft, a past NASA mission to Jupiter and its moons. Credit: NASA/JPL/University of Arizona

Planetary scientists have long desired a speedy to return on Europa, ever since the groundbreaking discoveries of NASA’s Galileo Jupiter orbiter in the 1990s showed that the alien world possessed a substantial and deep subsurface ocean beneath an icy shell that appears to interact with and alter the moon’s surface in recent times.

NASA’s Europa mission would blastoff perhaps as soon as 2022, depending on the budget allocation and rocket selection – whose candidates include the heavy lift Space Launch System (SLS) now under development to launch astronauts on deep space expedition to the Moon, Asteroids and Mars.

The solar powered Europa probe will go into orbit around Jupiter for a three year mission in order to minimize exposure to the intense radiation region that could harm the spacecraft.

The Europa mission goal is to investigate whether the tantalizing icy Jovian moon, similar in size to Earth’s moon, could harbor conditions suitable for the evolution and sustainability of life in the suspected ocean.

It will be equipped with high resolution cameras, spectrometers and radar, several generations beyond anything before to map the surface in unprecedented detail and determine the moon’s composition and subsurface character. And it will search for subsurface lakes and seek to sample erupting vapor plumes like those occurring today on Saturn’s tiny moon Enceladus.

There will many opportunities for close flybys of Europa during the three year primary mission to conduct unprecedented studies of the composition and structure of the surface, icy shell and oceanic interior.

“During the three year mission, the orbiter will conduct 45 close flyby’s of Europa,” Curt Niebur, Europa program scientist at NASA Headquarters in Washington, told Universe Today.

“These will occur about every two to three weeks.”

The close flyby’s will vary in altitude from 16 miles to 1,700 miles (25 kilometers to 2,700 kilometers).

Europa rising. The icy moon hangs above Jupiter cloud tops in a @NASANewHorizons image from 2007. Credit: NASA
Europa rising. The icy moon hangs above Jupiter cloud tops in a @NASANewHorizons image from 2007. Credit: NASA

The mission currently has a budget of about $10 million for 2015 and $30 Million in 2016. Over the next three years the mission concept will be further defined.

The mission will be managed by NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California and is expected to cost in the range of at least $2 Billion or more.

The nine science instruments are described in my earlier story- here. They will be developed and built by Johns Hopkins University Applied Physics Laboratory (APL); JPL; Arizona State University, Tempe; the University of Texas at Austin; Southwest Research Institute, San Antonio and the University of Colorado, Boulder.

This artist's rendering shows a concept for a future NASA mission to Europa in which a spacecraft would make multiple close flybys of the icy Jovian moon, thought to contain a global subsurface ocean. Credits: NASA/JPL-Caltech
This artist’s rendering shows a concept for a future NASA mission to Europa in which a spacecraft would make multiple close flybys of the icy Jovian moon, thought to contain a global subsurface ocean. Credits: NASA/JPL-Caltech

Right now there is another NASA probe bound for Jupiter, the solar powered Juno orbiter that will investigate the origin of the gas giant. But Juno will not be conducting any observations or flyby’s of Europa.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

………….

Learn more about SpaceX, Europa, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:

Jun 25-27: “SpaceX launch, Orion, Commercial crew, Curiosity explores Mars, MMS, Antares and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

Posted on by Nancy Atkinson

Stunning Movie Shows What Earth Looks Like to an Incoming Spacecraft

A mosaic of images of the Earth and Moon taken by the incoming Juno spacecraft as it flew past Earth in October 2013. Credit: NASA/JPL

When NASA’s Juno spacecraft flew past Earth in October of this year, it focused some of its cameras on the Earth-Moon system. Immediately after the flyby, images taken by the Junocam were released, but today, NASA released an amazing video taken by the Advanced Stellar Compass (ASC) camera, a low-light camera that is primarily used as a star tracking a navigation tool. Over the course of three days, it captured the orbital ballet-like dance between the Earth and Moon.

“This is profound, and I think our movie does the same thing as “Pale Blue Dot” image from Voyager, except it’s a movie instead of an image,” said Scott Bolton, Juno principal investigator, speaking during a press briefing from the American Geophysical Union conference today in San Fransisco. “Like Carl Sagan said, everything we know is on this dot. To me this says, ‘we’re all in this together.’”

The Oct. 9 flyby was a gravity assist, accelerating Juno out of the inner solar system and toward Jupiter’s orbit. The probe is expected to arrive at Jupiter on July 4, 2016.

The movie begins at 2:00 UTC on Oct. 6, more than four days before Juno’s closest approach, when the spacecraft was approximately 2.1 million miles (3.3 million kilometers) from Earth. Earth’s moon is seen transiting in front of our planet, and then moves out of frame toward the right as Juno enters the space inside the orbit of our natural satellite. As Juno gets closer to Earth, hints of clouds and continents are visible before the planet’s brightness overwhelms the cameras, which were not designed to image so bright an object. The sequence ends as Earth passes out of view, which corresponds to approximately 17:35 UTC Oct. 9 when Juno was at an altitude of about 47,000 miles (76,000 kilometers) above Earth’s surface.

“From a half-million kilometers out, the Moon is dark as charcoal and but Earth way brighter, as a shiny blue dot,” said John Joergensen, who lead the team that designed the star tracking cameras. “It’s amazing to think that all of humanity being scanned in this movie, and to see how small the Moon is relative to Earth.”

The cameras that took the images for the movie are located near the pointed tip of one of the spacecraft’s three solar-array arms. They are part of Juno’s Magnetic Field Investigation (MAG) and are normally used to determine the orientation of the magnetic sensors. These cameras look away from the sunlit side of the solar array, so as the spacecraft approached, the system’s four cameras pointed toward Earth. Earth and the moon came into view when Juno was about 600,000 miles (966,000 kilometers) away — about three times the Earth-moon separation.

During the flyby, timing was everything. Juno was traveling about twice as fast as a typical satellite, and the spacecraft itself was spinning at 2 rpm. To assemble a movie that wouldn’t make viewers dizzy, the star tracker had to capture a frame each time the camera was facing Earth at exactly the right instant. The frames were sent to Earth, where they were processed into video format.

As Juno is a spinning spacecraft, the images were aligned to remove their apparent rotation. The original ASC images are monochrome; faint coloration has been added by converting the measured grayscale values into false colors matching a true color image of Earth.

JPL press release