Tag: Juno

Jupiter’s Stripes Run Deep, But Hopefully Juno’s Problems Do Not

Though on holiday, I wanted to share these images and a bit of the Juno at Jupiter news.

This composite image depicts Jupiter's cloud formations as seen through the eyes of Juno's microwave radiometer (MWR) instrument as compared to the top layer, a Cassini imaging science subsystem image of the planet. The MWR can see a couple of hundred miles into Jupiter's atmosphere with the instrument's largest antenna. The belts and bands visible on the surface are also visible in modified form in each layer below. Credit: NASA/JPL-Caltech/SwRI/GSFC

This composite image depicts Jupiter’s cloud formations as seen through the eyes of Juno’s microwave radiometer (MWR) instrument as compared to the top layer, a Cassini imaging science subsystem image of the planet. The MWR can see a couple of hundred miles into Jupiter’s atmosphere with the instrument’s largest antenna. The belts and bands visible on the surface are also visible in modified form in each layer below. (NASA/JPL-Caltech/SwRI/GSFC)

Because telescopes have never been able to see clearly down through the thick clouds of Jupiters– the ones that together form the planet’s glorious stripes– it has remained a mystery how deep they may be.

Based on the Juno spacecraft’s August pass, we now know via its microwave radiometer that the stripes reflect dynamics that occur deep into the planet.

Scott Bolton, leader of the Juno mission reported the team’s conclusions during a press conference at the 2016 meeting of the American Astronomical Society’s Division for Planetary Sciences.

“The structure of the zones and belts still exists deep down,” Bolton said.  “So whatever is making those colors, whatever is making those stripes, is still existing pretty far down into Jupiter. That came as a surprise to many of the scientists. We didn’t know if this was [just] skin-deep.”

The new images penetrate to depths of about 200 to 250 miles below the surface cloud layer, Bolton said. While the bands seen on the cloud tops are not identical to the bands identified further down, there is a strong resemblance. “They’re evolving. They’re not staying the same,” Bolton said.

The findings have intriguing implications for exoplanet research.  Bolton said that the hint at “the deep dynamics and the chemistry of Jupiter’s atmosphere. And this is the first time we’ve seen any giant planet atmosphere underneath its layers. So we’re learning about atmospheric dynamics at a very basic level.”

Outer jets and belts composed largely of ammonia and hydrogen sulfide gas can block study of the inner atmosphere. Winds blow the cloud regions in different directions. (NASA)

Outer jets and belts composed largely of ammonia and hydrogen sulfide gas can block study of the inner atmosphere. Winds blow the cloud regions in different directions. (NASA/JPL-Caltech)

These early Juno findings came as it was also reported that the spacecraft had two malfunction that caused it to go into safe mode, just as it was approaching Jupiter for an October 19 flyby.

Right now, Juno makes one orbit every 53 days. Juno was scheduled to fire its engines on Oct.… Read more

Juno Now Orbiting Jupiter

Artist illustration of Juno as it approaches Jupiter. NASA

Artist illustration of Juno as it approaches Jupiter. (NASA)

It took a while — almost five years since launch — but the Juno spacecraft is now at Jupiter and orbiting the giant planet. A 35-minute rocket burn to slow Juno down from its record-breaking 130,000 mph entry speed led to a successful insertion into orbit just minutes before midnight, making it another July 4th NASA spectacular.

During its mission, Juno will orbit the planet 37 times, dipping as low as 2,600 miles above the planet’s upper clouds of ammonia and water.  Primary goals of the mission are to determine whether Jupiter has a solid rocky core or is made up of gases all the way through, to learn about its extraordinarily powerful magnetic forces, and to determine better the components of those upper clouds and what might lie beneath them.

The overriding purpose is to better understand how Jupiter — the first planet formed in our solar system — came to be, and consequently how our solar system was formed. Considering that Jupiter contains more matter than the rest of the solar system planets, moons, asteroids and comets combined, it clearly is the place to look to understand the origins of the solar system.

But another goal, and a significant one at that, is to learn about the big gas giant as a way to learn about similar planets orbiting other stars.  Woven into the Juno mission from the beginning was a requirement that the two years of orbiting be designed and operated with distant solar systems and exo-Jupiters in mind.

I had the opportunity to speak with Juno principal investigator Scott Bolton just the day before Juno’s arrival, and he made clear that providing information and insights that will help understand exo-Jupiters is a high priority, indeed.

 

Scott Bolton, principal investigator of the Juno mission. (NASA)

Scott Bolton, principal investigator of the Juno mission. (NASA)

“We know that our Jupiter is quite different from many of the other Jupiter-sized planets found, and so there will be differences,” he said.  “But the dynamics we find, the presence of a rocky core or not, the water abundances, the structure of the planet — I think that will all be extremely useful to exoplanet modelers and theorists.”

He also made the intriguing observation that there may well be links between Juno discoveries and the search for Earth-size planets around other stars.

“It may be that finding a system with a Jupiter of a size like ours,  and in  a location {in its solar system} similar to ours, would be a strong signal that there is also an Earth-sized planet in the system.”… Read more

Juno, Jupiter and Exo-Jupiters

Artist rendering of Juno spacecraft in orbit around Jupiter. NASA

Artist rendering of Juno spacecraft in orbit around Jupiter. NASA

The last NASA mission to orbit Jupiter, the Galileo, was designed, flown and its data analyzed as if it was circling the only Jupiter in the sky.

This is hardly surprising since the spacecraft launched in 1989, before the exoplanet era had arrived.  Ironically, Galileo entered its Jupiter orbit in late 1995,  just a few months after the first exoplanet was detected.

That planet, 51 Pegasi b, was a Jupiter-sized planet shockingly close to its host star, and its location and white-hot temperatures turned upside down many then-current theories about gas giant planets and their roles in the formation of solar system.  Scientists are still struggling to make sense of what 51 Pegasi b, and the 250 or so Jupiters found after it, are telling us.

So the Juno mission, which is scheduled to begin orbiting Jupiter on July 4, will arrive at a planet understood quite differently than when Galileo made its appearance.  Juno was built first and foremost to unravel some of the enduring mysteries of the planet:  When and where was it formed?  Does it have rocky core?  Is there water deep in the atmosphere?

But the spacecraft and its instruments will do their unraveling within our current, very different galactic context, where exoplanet scientists will be waiting for results with nearly as much eagerness and anticipation as solar system and planetary scientists.  And the findings from Juno may well have as much impact on the subsequent study of the many, many Jupiter-like planets known to exist in other solar systems as it does on the study of our solar system and its formation history.

Scott Bolton, principal investigator for Juno, recently told a NASA gathering that one of the primarily goals of Juno is to learn, through exploration of Jupiter, “the recipe” for the formation of our planets, our solar system, and those solar systems and planets well beyond Earth.

This is possible because Jupiter was the first planet formed after our sun, which is made almost entirely of hydrogen and helium.  Jupiter is also largely made up of those two elements, but it does have some additional heavy elements that somehow got there — carbon, nitrogen, phosphorus, important gases.

“We don’t know exactly how that happened, but we know that it’s really important,” Bolton said.  “That’s because the stuff that Jupiter has more of is what we’re all made of made of, and is what Earth is made out of, and what life comes from. … Read more

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