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NASA's Juno: Science Results Offer First 3D View of Jupiter Atmosphere – Net Newsledger

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This illustration combines an image of Jupiter from the JunoCam instrument aboard NASA’s Juno spacecraft with a composite image of Earth to depict the size and depth of Jupiter’s Great Red Spot.
Credits: JunoCam Image data: NASA/JPL-Caltech/SwRI/MSSS; JunoCam Image processing by Kevin M. Gill (CC BY); Earth Image: NASA

New findings from NASA’s Juno probe orbiting Jupiter provide a fuller picture of how the planet’s distinctive and colorful atmospheric features offer clues about the unseen processes below its clouds. The results highlight the inner workings of the belts and zones of clouds encircling Jupiter, as well as its polar cyclones and even the Great Red Spot.

“These new observations from Juno open up a treasure chest of new information about Jupiter’s enigmatic observable features,” said Lori Glaze, director of NASA’s Planetary Science Division at the agency’s headquarters in Washington. “Each paper sheds light on different aspects of the planet’s atmospheric processes – a wonderful example of how our internationally-diverse science teams strengthen understanding of our solar system.”

Juno entered Jupiter’s orbit in 2016. During each of the spacecraft’s 37 passes of the planet to date, a specialized suite of instruments has peered below its turbulent cloud deck.

“Previously, Juno surprised us with hints that phenomena in Jupiter’s atmosphere went deeper than expected,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio and lead author of the Journal Science paper on the depth of Jupiter’s vortices. “Now, we’re starting to put all these individual pieces together and getting our first real understanding of how Jupiter’s beautiful and violent atmosphere works – in 3D.”

Juno’s microwave radiometer (MWR) allows mission scientists to peer beneath Jupiter’s cloud tops and probe the structure of its numerous vortex storms. The most famous of these storms is the iconic anticyclone known as the Great Red Spot. Wider than Earth, this crimson vortex has intrigued scientists since its discovery almost two centuries ago.

The new results show that the cyclones are warmer on top, with lower atmospheric densities, while they are colder at the bottom, with higher densities. Anticyclones, which rotate in the opposite direction, are colder at the top but warmer at the bottom.

The findings also indicate these storms are far taller than expected, with some extending 60 miles (100 kilometers) below the cloud tops and others, including the Great Red Spot, extending over 200 miles (350 kilometers). This surprise discovery demonstrates that the vortices cover regions beyond those where water condenses and clouds form, below the depth where sunlight warms the atmosphere.

The height and size of the Great Red Spot means the concentration of atmospheric mass within the storm potentially could be detectable by instruments studying Jupiter’s gravity field. Two close Juno flybys over Jupiter’s most famous spot provided the opportunity to search for the storm’s gravity signature and complement the MWR results on its depth.

With Juno traveling low over Jupiter’s cloud deck at about 130,000 mph (209,000 kph) Juno scientists were able to measure velocity changes as small 0.01 millimeter per second using a NASA’s Deep Space Network tracking antenna, from a distance of more than 400 million miles (650 million kilometers). This enabled the team to constrain the depth of the Great Red Spot to about 300 miles (500 kilometers) below the cloud tops.

“The precision required to get the Great Red Spot’s gravity during the July 2019 flyby is staggering,” said Marzia Parisi, a Juno scientist from NASA’s Jet Propulsion Laboratory in Southern California and lead author of a paper in the Journal Science on gravity overflights of the Great Red Spot. “Being able to complement MWR’s finding on the depth gives us great confidence that future gravity experiments at Jupiter will yield equally intriguing results.”

Belts and Zones

In addition to cyclones and anticyclones, Jupiter is known for its distinctive belts and zones – white and reddish bands of clouds that wrap around the planet. Strong east-west winds moving in opposite directions separate the bands. Juno previously discovered that these winds, or jet streams, reach depths of about 2,000 miles (roughly 3,200 kilometers). Researchers are still trying to solve the mystery of how the jet streams form. Data collected by Juno’s MWR during multiple passes reveal one possible clue: that the atmosphere’s ammonia gas travels up and down in remarkable alignment with the observed jet streams.

“By following the ammonia, we found circulation cells in both the north and south hemispheres that are similar in nature to ‘Ferrel cells,’ which control much of our climate here on Earth”, said Keren Duer, a graduate student from the Weizmann Institute of Science in Israel and lead author of the Journal Science paper on Ferrel-like cells on Jupiter. “While Earth has one Ferrel cell per hemisphere, Jupiter has eight – each at least 30 times larger.”

Juno’s MWR data also shows that the belts and zones undergo a transition around 40 miles (65 kilometers) beneath Jupiter’s water clouds. At shallow depths, Jupiter’s belts are brighter in microwave light than the neighboring zones. But at deeper levels, below the water clouds, the opposite is true – which reveals a similarity to our oceans.

“We are calling this level the ‘Jovicline’ in analogy to a transitional layer seen in Earth’s oceans, known as the thermocline – where seawater transitions sharply from being relative warm to relative cold,” said Leigh Fletcher, a Juno participating scientist from the University of Leicester in the United Kingdom and lead author of the paper in the Journal of Geophysical Research: Planets highlighting Juno’s microwave observations of Jupiter’s temperate belts and zones.

Polar Cyclones

Juno previously discovered polygonal arrangements of giant cyclonic storms at both of Jupiter’s poles – eight arranged in an octagonal pattern in the north and five arranged in a pentagonal pattern in the south. Now, five years later, mission scientists using observations by the spacecraft’s Jovian Infrared Auroral Mapper (JIRAM) have determined these atmospheric phenomena are extremely resilient, remaining in the same location.

“Jupiter’s cyclones affect each other’s motion, causing them to oscillate about an equilibrium position,” said Alessandro Mura, a Juno co-investigator at the National Institute for Astrophysics in Rome and lead author of a recent paper in Geophysical Research Letters on oscillations and stability in Jupiter’s polar cyclones. “The behavior of these slow oscillations suggests that they have deep roots.”

JIRAM data also indicates that, like hurricanes on Earth, these cyclones want to move poleward, but cyclones located at the center of each pole push them back. This balance explains where the cyclones reside and the different numbers at each pole.

More About the Mission

JPL, a division of Caltech in Pasadena, California, manages the Juno mission. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. Lockheed Martin Space in Denver built and operates the spacecraft.

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Here's what the only total solar eclipse of 2021 was like from a cruise ship near Antarctica – Space.com

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Editor’s note: The only total solar eclipse of 2021 occurred Saturday, Dec. 4, over Antarctica, where few people could see it. Some intrepid explorers, like our columnist Joe Rao, attempted to see the eclipse from cruise ships near Antarctica. Here’s what Joe and his ship saw.

FROM THE LE COMMANDANT CHARCOT IN THE SOUTHERN OCEAN OFF OF ANTARCTICA — Approximately 200 passengers on board this exploration cruise ship, owned by the French cruise line, Ponant, sadly suffered a complete cloud out of this total solar eclipse, which swept across a part of the frozen Antarctic continent on Saturday.

Late Friday evening, Captain Etienne Garcia, Master of the Le Commandant Charcot, reversed the course of the ship. It had been previously heading on a southeast trajectory just to the east of the center-line of the eclipse track, but based on a check of satellite imagery, Captain Garcia decided to turn and head on a northwest trajectory and maneuver the ship closer to the eclipse center line. The satellite images had shown a more-or-less general cloud cover, but the search was on for some thin spots which might have provided some partial visibility.

Photos: Amazing 2021 total solar eclipse views from Antarctica

Image 1 of 1

A view from the stern of Le Commandant Charcot looking up toward the ship’s bridge under overcast skies prior to the start of the total solar eclipse of 2021. (Image credit: Joe Rao)

Solar Eclipse Photography Guide

Unfortunately, during the overnight hours as the temperatures cooled the overcast only became thicker. And the passengers and crew who gathered at the stern of the ship after 3 a.m. (“Chilean Summer Time”) only saw gray skies.

At the time it encountered the moon’s dark umbral shadow, the 30,000-ton exploration vessel was located near 57.72 degrees south and 44.02 degrees west, to the northeast of the South Orkney Islands. About 20 minutes before second contact, the start of the total phase of the eclipse, passengers began to notice a subtle diminution of the light levels and it really began accelerating toward darkening in the final couple of minutes before totality as the moon’s shadow raced toward us from the northeast at 3,100 mph.

Related: The 8 most famous solar eclipses in history

The moment of totality of the total solar eclipse of 2021 from the deck of the  Le Commandant Charcot in the sea near the coast of Antarctica on Dec. 4, 2021. The sky was clouded out, but is considerably darker and lights can be seen shining on the ship’s bridge. (Image credit: Joe Rao)

A number of petrels — tube-nosed seabirds indiginous to this part of the world —were flying and swooping around the ship as the darkness was coming on and we also caught sight of two whales that breached the sea surface alongside our ship. Whether they were all reacting to the darkening sky is debatable, but certainly a possibility.

Totality lasted 97 seconds. No distinct shadow or cone of darkness was noted. Rather, just an amorphous darkening of the sky — like someone turning down a rheostat or dimmer switch. No colors were seen and the end of totality seemed more pronounced as the light seemed to come back quicker than it when it faded away.

During totality, it actually began to drizzle very lightly and a few minutes after third contact it actually started to snow lightly. The air temperature hovered at around 0C (32F), but factoring in the winds made it feel noticeably colder.

Related: The stages of the 2021 total solar eclipse explained

Captain Etienne Garcia, Master of the Le Commandant Charcot, making last-minute course corrections in an attempt to locate a break in the clouds for a view of the total eclipse. (Image credit: Joe Rao)

Well … we gave it our best shot, but unfortunately came up empty. Those who had never experienced a total solar eclipse, were impressed by the dramatic darkening of the sky, but for those like myself, who knew what was hidden from our view behind the cloud deck, it was quite disappointing.

I knew when I accepted this assignment to work with Captain Garcia and his staff, that the weather odds were long for success based on long-term climate records for this part of the world. It is nonetheless hard to take, considering how brilliantly sunny our skies were in the two days prior to the eclipse.

This was eclipse number 13 for me . . . the very first dating back to July 1972; only my second cloud-out (the first was 44 years ago in Colombia, October 1977). My batting average for eclipse success is 84.7%, so I really have little to complain about — but a bitter defeat nonetheless.

On a bright note, with today’s 97 seconds, I have now spent over 30 minutes “basking” in the shadow of the moon. 

Back in 1973, I was at a gathering of eclipse chasers at the Hayden Planetarium where Dr. Charles Hugh Smiley of Brown University was attending. The Director at Hayden, Mark Chartrand said that Dr. Smiley had spent more than 30 minutes in the Moon’s umbra, “An unprecedented total!” gushed Dr. Chartrand. I thought to myself at that time that I would never come remotely close to Dr. Smiley’s record, but with today’s eclipse I have. 

Dr. Smiley (who passed away in 1977), ended his career having observed 14 eclipses. Today, many veteran eclipse chasers have seen more than 20 total eclipses and a few individuals, such as solar physicist, Dr. Jay Pasachoff of Williams College in Massachusetts and Dr. Glenn Schneider of the University of Arizona’s Steward Observatory, have seen more than 30!

Sadly ironic that on the day before the eclipse, the skies were brilliantly sunny.  Here is Renate Rao (my wife), enjoying the cold Antarctic sunshine.  Note the large iceberg in the Southern Ocean behind her.  (Image credit: Joe Rao)

At least one cruise ship did get a view of the totally eclipsed sun. Word reached us that National Geographic’s ship “Endurance” managed to sight the sun’s corona between clouds at a position near the beginning of today’s totality path. There were also chartered flights that took observers about 33,000-feet above the cloud cover for airborne views of this morning’s celestial spectacle.

In all, it is estimated that fewer than 3000 people attended observation of today’s total eclipse. 

Another member of the Ponant cruise ships, the Le Boreal, passed our ship on its way north to position itself along the totality path.  A wayward petral photobombed it in this view. (Image credit: Joe Rao)

Related stories:

The next total eclipse on April 20, 2023, will actually be an unusual annular-total, or “hybrid” eclipse, in which along part of the eclipse path an annular or ring eclipse is seen, while along other parts of the eclipse path the eclipse is total. Most eclipse watchers are likely to converge on Cape Range National Park in Western Australia, where totality will last for 62 seconds.

On April 8, 2024, a total eclipse will cross parts of Northern Mexico and the Southern and Eastern United States and Eastern Canada. About 35 million people live in the totality path of this eclipse with the total phase in some cases exceeding 4 minutes.

Editor’s Note: If you snap an amazing solar eclipse photo and would like to share it with Space.com’s readers, send your photo(s), comments, and your name and location to spacephotos@space.com.

Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers’ Almanac and other publications. Follow us on Twitter @Spacedotcom and on Facebook

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Scientists observe total solar eclipse in Antarctica – Global Times

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Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

 
Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

 

Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

 

Photo taken from Chilean Union Glacier Station in Antarctica on Dec. 4, 2021 shows a total solar eclipse.Photo:Xinhua

Photo taken from Chilean Union Glacier Station in Antarctica on Dec. 4, 2021 shows a total solar eclipse.Photo:Xinhua

 

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Dinosaur Tail Found In Chile Could Point To Discovery Of New Species – NDTV

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Paleontologists have discovered 80 percent of the dinosaur’s skeleton.

Santiago:

Chilean paleontologists on Wednesday presented their findings on a dinosaur discovered three years ago in Patagonia which they said had a highly unusual tail that has stumped researchers.

The remains of the Stegouros elengassen were discovered during excavations in 2018 at Cerro Guido, a site known to harbor numerous fossils, by a team who believed they were dealing with an already known species of dinosaur until they examined its tail.

“That was the main surprise,” said Alexander Vargas, one of the paleontologists. “This structure is absolutely amazing.”

“The tail was covered with seven pairs of osteoderms … producing a weapon absolutely different from anything we know in any dinosaur,” added the researcher during a presentation of the discovery at the University of Chile.

The osteoderms — structures of bony plaques located in the dermal layers of the skin – were aligned on either side of the tail, making it resemble a large fern.

Paleontologists have discovered 80 percent of the dinosaur’s skeleton and estimate that the animal lived in the area 71 to 74.9 million years ago. It was about two meters (almost seven feet) long, weighed 150 kilograms (330 pounds) and was a herbivore.

According to the scientists, who published their research in the journal Nature, the animal could represent a hitherto unknown lineage of armored dinosaur never seen in the southern hemisphere but already identified in the northern part of the continent.

“We don’t know why (the tail) evolved. We do know that within armored dinosaur groups there seems to be a tendency to independently develop different osteoderm-based defense mechanisms,” said Sergio Soto, another member of the team.

The Cerro Guido area, in the Las Chinas valley 3,000 km (1,800 miles) south of Santiago, stretches for 15 kilometers. Various rock outcrops contain numerous fossils.

The finds there allowed the scientists to surmise that present-day America and Antarctica were close to each other millions of years ago.

“There is strong evidence that there is a biogeographic link with other parts of the planet, in this case Antarctica and Australia, because we have two armored dinosaurs there closely related” to the Stegouros, said Soto.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

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