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This enhanced-color composite photo shows Jupiter’s south pole from NASA’s Juno spacecraft 32,000 miles above the gas giant. The oval features are cyclones up to 600 miles wide.
NASA/JPL-Caltech/SwRI/MSSS/Betsy Asher Hall/Gervasio Robles

Much of What We Thought About Jupiter Is Wrong

Original image
This enhanced-color composite photo shows Jupiter’s south pole from NASA’s Juno spacecraft 32,000 miles above the gas giant. The oval features are cyclones up to 600 miles wide.
NASA/JPL-Caltech/SwRI/MSSS/Betsy Asher Hall/Gervasio Robles

Scientists have had time to study the data returned from the NASA spacecraft Juno and are discovering that pretty much everything they thought they knew about Jupiter’s interior is wrong. “I think we’re all sort of feeling the humility and humbleness,” said Scott Bolton, the principal investigator of Juno, during a press teleconference today, May 25. “It is making us rethink how giant planets work not only in our system but throughout the galaxy.”

The findings from Juno’s initial Jupiter orbits were published today in the journals Science and Geophysical Research Letters. The latter is a special issue devoted to Juno data and includes more than two dozen reports.

TEXAS-SIZED AMMONIA CYCLONES ARE ONLY THE BEGINNING

Juno, which launched in 2011 and entered Jupiter's orbit on July 4, 2016, is the first spacecraft to give scientists a real view of Jupiter’s poles, and what they’ve found is unlike anything expected.

“Jupiter from the poles doesn’t look anything like it does from the equator,” Bolton said.

Images reveal that Jupiter’s famous bands do not continue to the north and south poles. Rather, the poles are characterized by a bluish hue, chaotic swirls, and ovular features, which are Texas-sized ammonia cyclones. The precise mechanism behind them is unknown. Their stability is equally a mystery. As the Juno mission progresses, repeat visits to the poles and new data on the evolution of the cyclones will answer some of these questions.

The poles aren't identical, either. “The fact that the north and south pole don’t really look like each other is also a puzzle to us,” Bolton said.

One interesting observation was a happy accident. Because of Juno’s unique orbit, the spacecraft always crosses a terminator—that is, the line dividing where the planet is in full illumination of the Sun, and the far side, in total darkness. This is useful because topological relief can be seen at this line. (To see this in action, look through a telescope at a half-full moon. The shadows where light meets dark give a vivid sense of the heights of mountains and the depths of craters.) During an orbit, there happened to be a 4300-mile-wide storm at Jupiter’s terminator near the north pole, and scientists noticed shadows. The storm was towering over its cloud surroundings like a tornado on a Kansas prairie.

INTENSE PRESSURE SQUEEZES HYDROGEN INTO A METALLIC FLUID

03_scott_3 jupiter core.jpg

Jupiter's core with metallic hydrogen fluid envelope
What may lie within the heart of Jupiter: a possible inner “rock” core surrounded by metallic hydrogen and an outer envelope of molecular hydrogen, all hidden beneath the visible cloud deck.
NASA/JPL-Caltech/SwRI

Bolton explained that the goal of Juno is "looking inside Jupiter pretty much every way we know how.” Juno carries an instrument called a microwave radiometer, designed to see through Jupiter’s clouds and to collect data on the dynamics and composition of its deep atmosphere. (The instrument is sensitive to water and ammonia but is presently looking only at ammonia.) So far, the data are mystifying and wholly unexpected. Most scientists previously believed that just below the clouds, Jupiter’s atmosphere is well mixed. Juno has found just the opposite: that levels of ammonia vary greatly, and that the structure of the atmosphere does not match the visible zones and belts. Ammonia is emanating from great depths of the planet and driving weather systems.

Scientists still don’t know whether Jupiter has a core, or what it’s composed of if it exists. For insight, they’re studying the planet’s magnetosphere. Deep inside the gas giant, the pressure is so great that the element hydrogen has been squeezed into a metallic fluid. (Atmospheric pressure is measured in bars. Pressure at the surface of the Earth is one bar. On Jupiter, it’s 2 million. And at the core it would be around 40 million bars.) The movement of this liquid metallic hydrogen is thought by scientists to create the planet’s magnetic field. By studying the field, Juno can unlock the mysteries of the core’s depth, size, density, and even whether it exists, as predicted, as a solid rocky core. “We were originally looking for a compact core or no core,” Bolton said, “but we’re finding that it’s fuzzy—perhaps partially dissolved.”

Jupiter’s magnetosphere is the second-largest structure in the solar system, behind only the heliosphere itself. (The heliosphere is the total area influenced by the Sun. Beyond it is interstellar space.) So far, scientists are dumbfounded by the strength of the magnetic field close to the cloud tops—and by its deviations. “What we’ve found is that the magnetic field is both stronger than where we expected it to be strong, and weaker where we expected it to be weak,” said Jack Connerney, the deputy principal investigator of Juno.

Another paper today in Science revealed new findings about Jupiter’s auroras. The Earth’s auroras are Sun-driven, the result of the interaction of the solar winds and Earth’s magnetosphere. Jupiter’s auroras have been known for a while to be different, and related to the planet’s rotation. Juno has taken measurements of the magnetic field and charged particles causing the auroras, and has also taken the first images of the southern aurora. The processes at work are still unknown, but the takeaway is that the mechanics behind Jupiter’s auroras are unlike those of Earth, and call into question how Jupiter interacts with its environment in space.

JUNO ALREADY HAS US REWRITING THE TEXTBOOKS

19-candy-3 juno primary.jpg

An enhanced-color closeup of swirling waves of clouds, some just 4 miles across. Some of the small, bright high clouds seem to form squall lines, or a narrow band of high winds and storms associated with a cold front. They're likely composed of water and/or ammonia ice.
NASA/SWRI/MSSS/Gerald Eichstädt/Seán Doran

Understanding Jupiter is essential to understanding not only how our solar system formed, but how the new systems being discovered around stars form and operate as well. The next close approach of Jupiter will take place on July 11, when Juno flies directly over the famed Great Red Spot. Scientists hope to learn more about its depth, action, and drivers.

Juno already has us rewriting the textbooks, and it's only at the beginning of its orbital mission. It's slated to perform 33 polar orbits of Jupiter, each lasting 53.5 days. So far, it's completed only five. The spacecraft’s prime mission will end next year, at which time NASA will have to decide whether it can afford to extend the mission or to send Juno into the heart of Jupiter, where it will be obliterated. This self-destruct plunge would protect that region of space from debris and local, potentially habitable moons from contamination.

Bolton tells Mental Floss that the surprising findings really bring home the fact that to unlock Jupiter, this mission will need to be seen through to completion. “That’s what exciting about exploration: We’re going to a place we’ve never been before and making new discoveries … we’re just scratching the surface.” he says. “Juno is the right tool to do this. We have the right instruments. We have the right orbit. We’re going to win over this beast and learn how it works.”

Original image
This enhanced-color composite photo shows Jupiter’s south pole from NASA’s Juno spacecraft 32,000 miles above the gas giant. The oval features are cyclones up to 600 miles wide.
iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

Original image
This enhanced-color composite photo shows Jupiter’s south pole from NASA’s Juno spacecraft 32,000 miles above the gas giant. The oval features are cyclones up to 600 miles wide.
iStock
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technology
Why Your iPhone Doesn't Always Show You the 'Decline Call' Button
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iStock

When you get an incoming call to your iPhone, the options that light up your screen aren't always the same. Sometimes you have the option to decline a call, and sometimes you only see a slider that allows you to answer, without an option to send the caller straight to voicemail. Why the difference?

A while back, Business Insider tracked down the answer to this conundrum of modern communication, and the answer turns out to be fairly simple.

If you get a call while your phone is locked, you’ll see the "slide to answer" button. In order to decline the call, you have to double-tap the power button on the top of the phone.

If your phone is unlocked, however, the screen that appears during an incoming call is different. You’ll see the two buttons, "accept" or "decline."

Either way, you get the options to set a reminder to call that person back or to immediately send them a text message. ("Dad, stop calling me at work, it’s 9 a.m.!")

[h/t Business Insider]

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