Orbits

The instant she did it – and it truly wasn’t much of an it, the movement really just a very light rub of her abdomen that could have meant anything, had she been more careful about the tightness of her blouse it might have been avoided – she realized her mistake, but Leia powered through anyway, moving briskly into the analytics section of the briefing she was leading regarding an upcoming exploratory mission. 

And really, how many recruits could possibly have heard the low whisper from about three rows back? Maybe the half-dozen immediately surrounding? But that was it – and half-dozen people privy to think the ice princess might be knocked up was nothing she couldn’t handle with a curt glance and firm dismissal. Not the first time people had called her cold, and not even the first time people had thought her pregnant – though yes, it was the first time they were right.

But her – boyfriend, lover, partner, however he was being referred to in relation to her these days – twisting around and drawling, voice low and wry, Watch it, that’s my kid you’re talking about? That she was not quite sure how to come back from. That definitely warranted more than the withering death-glare she gave him before returning, straight-backed and haughty, to the briefing she was now determined to finish despite the flood of whispering. It definitely warranted more, but she might as well start there.  

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Hi everyone, @vstolbunovhere again. Today I am sharing some of my astro timelapse work here on @universetoday!

This second one is from Ojochal, Costa Rica. I shot this among the palm trees, facing directly up. The three different rates of motion (stars, clouds, trees) are my favorite part of this timelapse. To avoid the typical quick-moving astro timelapse, I shot this at faster shutter but higher ISO.

Incoming! We’ve Got Science from Jupiter!

Our Juno spacecraft has just released some exciting new science from its first close flyby of Jupiter! 

In case you don’t know, the Juno spacecraft entered orbit around the gas giant on July 4, 2016…about a year ago. Since then, it has been collecting data and images from this unique vantage point.

Juno is in a polar orbit around Jupiter, which means that the majority of each orbit is spent well away from the gas giant. But once every 53 days its trajectory approaches Jupiter from above its north pole, where it begins a close two-hour transit flying north to south with its eight science instruments collecting data and its JunoCam camera snapping pictures.

Space Fact: The download of six megabytes of data collected during the two-hour transit can take one-and-a-half days!

Juno and her cloud-piercing science instruments are helping us get a better understanding of the processes happening on Jupiter. These new results portray the planet as a complex, gigantic, turbulent world that we still need to study and unravel its mysteries.

So what did this first science flyby tell us? Let’s break it down…

1. Tumultuous Cyclones

Juno’s imager, JunoCam, has showed us that both of Jupiter’s poles are covered in tumultuous cyclones and anticyclone storms, densely clustered and rubbing together. Some of these storms as large as Earth!

These storms are still puzzling. We’re still not exactly sure how they formed or how they interact with each other. Future close flybys will help us better understand these mysterious cyclones. 

Seen above, waves of clouds (at 37.8 degrees latitude) dominate this three-dimensional Jovian cloudscape. JunoCam obtained this enhanced-color picture on May 19, 2017, at 5:50 UTC from an altitude of 5,500 miles (8,900 kilometers). Details as small as 4 miles (6 kilometers) across can be identified in this image.

An even closer view of the same image shows small bright high clouds that are about 16 miles (25 kilometers) across and in some areas appear to form “squall lines” (a narrow band of high winds and storms associated with a cold front). On Jupiter, clouds this high are almost certainly comprised of water and/or ammonia ice.

2. Jupiter’s Atmosphere

Juno’s Microwave Radiometer is an instrument that samples the thermal microwave radiation from Jupiter’s atmosphere from the tops of the ammonia clouds to deep within its atmosphere.

Data from this instrument suggest that the ammonia is quite variable and continues to increase as far down as we can see with MWR, which is a few hundred kilometers. In the cut-out image below, orange signifies high ammonia abundance and blue signifies low ammonia abundance. Jupiter appears to have a band around its equator high in ammonia abundance, with a column shown in orange.

Why does this ammonia matter? Well, ammonia is a good tracer of other relatively rare gases and fluids in the atmosphere…like water. Understanding the relative abundances of these materials helps us have a better idea of how and when Jupiter formed in the early solar system.

This instrument has also given us more information about Jupiter’s iconic belts and zones. Data suggest that the belt near Jupiter’s equator penetrates all the way down, while the belts and zones at other latitudes seem to evolve to other structures.

3. Stronger-Than-Expected Magnetic Field

Prior to Juno, it was known that Jupiter had the most intense magnetic field in the solar system…but measurements from Juno’s magnetometer investigation (MAG) indicate that the gas giant’s magnetic field is even stronger than models expected, and more irregular in shape.

At 7.766 Gauss, it is about 10 times stronger than the strongest magnetic field found on Earth! What is Gauss? Magnetic field strengths are measured in units called Gauss or Teslas. A magnetic field with a strength of 10,000 Gauss also has a strength of 1 Tesla.  

Juno is giving us a unique view of the magnetic field close to Jupiter that we’ve never had before. For example, data from the spacecraft (displayed in the graphic above) suggests that the planet’s magnetic field is “lumpy”, meaning its stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action (where the motion of electrically conducting fluid creates a self-sustaining magnetic field) closer to the surface, above the layer of metallic hydrogen. Juno’s orbital track is illustrated with the black curve. 

4. Sounds of Jupiter

Juno also observed plasma wave signals from Jupiter’s ionosphere. This movie shows results from Juno’s radio wave detector that were recorded while it passed close to Jupiter. Waves in the plasma (the charged gas) in the upper atmosphere of Jupiter have different frequencies that depend on the types of ions present, and their densities. 

Mapping out these ions in the jovian system helps us understand how the upper atmosphere works including the aurora. Beyond the visual representation of the data, the data have been made into sounds where the frequencies
and playback speed have been shifted to be audible to human ears.

5. Jovian “Southern Lights”

The complexity and richness of Jupiter’s “southern lights” (also known as auroras) are on display in this animation of false-color maps from our Juno spacecraft. Auroras result when energetic electrons from the magnetosphere crash into the molecular hydrogen in the Jovian upper atmosphere. The data for this animation were obtained by Juno’s Ultraviolet Spectrograph. 

During Juno’s next flyby on July 11, the spacecraft will fly directly over one of the most iconic features in the entire solar system – one that every school kid knows – Jupiter’s Great Red Spot! If anybody is going to get to the bottom of what is going on below those mammoth swirling crimson cloud tops, it’s Juno.

Stay updated on all things Juno and Jupiter by following along on social media:
Twitter | Facebook | YouTube | Tumblr

Learn more about the Juno spacecraft and its mission at Jupiter HERE.

The Start of Cassini’s Grand Finale

Cue drumroll…

For the first time ever, our Cassini spacecraft dove through the narrow gap between Saturn and its rings on April 26. At 5 a.m. EDT, Cassini crossed the ring plane with its science instruments turned on and collecting data. 

During this dive, the spacecraft was not in contact with Earth. The first opportunity to regain contact with the spacecraft is expected around 3 a.m. EDT on April 27.

This area between Saturn and its rings has never been explored by a spacecraft before. What we learn from these daring final orbits will further our understanding of how giant planets, and planetary systems everywhere, form and evolve.

So, you might be asking…how did this spacecraft maneuver its orbit between Saturn and its rings? Well…let us explain!

On April 22, Cassini made its 127th and final close approach to Saturn’s moon Titan. The flyby put the spacecraft on course for its dramatic last act, known as the Grand Finale. 

As the spacecraft passed over Titan, the moon’s gravity bent its path, reshaping the robotic probe’s orbit slightly so that instead of passing just outside Saturn’s main rings, Cassini would begin a series of 22 dives between the rings and the planet.

With this assist, Cassini received a large increase in velocity of approximately 1,925 mph with respect to Saturn.

This final chapter of exploration and discovery is in many ways like a brand-new mission. Twenty-two times, the Cassini spacecraft will dive through the unexplored space between Saturn and its rings. What we learn from these ultra-close passes over the planet could be some of the most exciting revelations ever returned by the long-lived spacecraft.

Throughout these daring maneuvers, updates will be posted on social media at:

@CassiniSaturn on Twitter
@NASAJPL on Twitter

Updates will also be available online at: https://saturn.jpl.nasa.gov/mission/grand-finale/milestones/ 

Follow along with us during this mission’s Grand Finale!

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Happy Martian New Year!

For any planet, a year is the time it takes to make one orbit around the sun. Because Mars is farther away from the sun, it has to travel a greater distance than Earth. It takes Mars about twice as long as it does for Earth to make one circle around the sun…therefore, a year on Mars lasts twice as long.

On May 5, Mars passes solar longitude 0 as the sun crosses the equator on Mars. This is the vernal equinox and was chosen by planetary scientists as the start of a new year.

Mars has four seasons, roughly twice as long as those on Earth, but with more variation given Mars’ eccentric orbit and the fact its orbital speed varies more as a result.

Did you know that there’s a U.S. city named Mars? Mars, PA hosts an annual Mars New Year celebration and we’re participating in this two-day science, technology, engineering and math (STEM) event to inspire young people to pursue innovation and exploration.

More info on Mars, PA: http://www.marsnewyear.com/

Get updated images from the events in Mars, PA here: https://www.flickr.com/photos/nasahqphoto/sets/72157683457751005/

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com