Much of What We Thought About Jupiter Is Wrong

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.
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

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


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.”

5 Signs Humans Are Still Evolving

Lealisa Westerhoff, AFP/Getty Images
Lealisa Westerhoff, AFP/Getty Images

When we think of human evolution, our minds wander back to the millions of years it took natural selection to produce modern-day man. Recent research suggests that, despite modern technology and industrialization, humans continue to evolve. "It is a common misunderstanding that evolution took place a long time ago, and that to understand ourselves we must look back to the hunter-gatherer days of humans," Dr. Virpi Lummaa, a professor at the University of Turku, told Gizmodo.

But not only are we still evolving, we're doing so even faster than before. In the last 10,000 years, the pace of our evolution has sped up, creating more mutations in our genes, and more natural selections from those mutations. Here are some clues that show humans are continuing to evolve.

1. Humans drink milk.

Historically, the gene that regulated humans' ability to digest lactose shut down as we were weaned off our mothers' breast milk. But when we began domesticating cows, sheep, and goats, being able to drink milk became a nutritionally advantageous quality, and people with the genetic mutation that allowed them to digest lactose were better able to propagate their genes.

The gene was first identified in 2002 in a population of northern Europeans that lived between 6000 and 5000 years ago. The genetic mutation for digesting milk is now carried by more than 95 percent of northern European descendants. In addition, a 2006 study suggests this tolerance for lactose developed again, independently of the European population, 3000 years ago in East Africa.

2. We're losing our wisdom teeth.

Our ancestors had much bigger jaws than we do, which helped them chew a tough diet of roots, nuts, and leaves. And what meat they ate they tore apart with their teeth, all of which led to worn-down chompers that needed replacing. Enter the wisdom teeth: A third set of molars is believed to be the evolutionary answer to accommodate our ancestors' eating habits.

Today, we have utensils to cut our food. Our meals are softer and easier to chew, and our jaws are much smaller, which is why wisdom teeth are often impacted when they come in — there just isn't room for them. Unlike the appendix, wisdom teeth have become vestigial organs. One estimate says 35 percent of the population is born without wisdom teeth, and some say they may disappear altogether.

3. We're resisting infectious diseases.

In 2007, a group of researchers looking for signs of recent evolution identified 1800 genes that have only become prevalent in humans in the last 40,000 years, many of which are devoted to fighting infectious diseases like malaria. More than a dozen new genetic variants for fighting malaria are spreading rapidly among Africans. Another study found that natural selection has favored city-dwellers. Living in cities has produced a genetic variant that allows us to be more resistant to diseases like tuberculosis and leprosy. "This seems to be an elegant example of evolution in action," says Dr. Ian Barnes, an evolutionary biologist at London's Natural History Museum, said in 2010 statement. "It flags up the importance of a very recent aspect of our evolution as a species, the development of cities as a selective force."

4. Our brains are shrinking.

While we may like to believe our big brains make us smarter than the rest of the animal world, our brains have actually been shrinking over the last 30,000 years. The average volume of the human brain has decreased from 1500 cubic centimeters to 1350 cubic centimeters, which is an amount equivalent to the size of a tennis ball.

There are several different conclusions as to why this is: One group of researchers suspects our shrinking brains mean we are in fact getting dumber. Historically, brain size decreased as societies became larger and more complex, suggesting that the safety net of modern society negated the correlation between intelligence and survival. But another, more encouraging theory says our brains are shrinking not because we're getting dumber, but because smaller brains are more efficient. This theory suggests that, as they shrink, our brains are being rewired to work faster but take up less room. There's also a theory that smaller brains are an evolutionary advantage because they make us less aggressive beings, allowing us to work together to solve problems, rather than tear each other to shreds.

5. Some of us have blue eyes.

Originally, we all had brown eyes. But about 10,000 years ago, someone who lived near the Black Sea developed a genetic mutation that turned brown eyes blue. While the reason blue eyes have persisted remains a bit of a mystery, one theory is that they act as a sort of paternity test. “There is strong evolutionary pressure for a man not to invest his paternal resources in another man’s child,” Bruno Laeng, lead author of a 2006 study on the development of blue eyes, told The New York Times. Because it is virtually impossible for two blue-eyed mates to create a brown-eyed baby, our blue-eyed male ancestors may have sought out blue-eyed mates as a way of ensuring fidelity. This would partially explain why, in a recent study, blue-eyed men rated blue-eyed women as more attractive compared to brown-eyed women, whereas females and brown-eyed men expressed no preference.

Now Ear This: A New App Can Detect a Child's Ear Infection

iStock.com/Techin24
iStock.com/Techin24

Generally speaking, using an internet connection to diagnose a medical condition is rarely recommended. But technology is getting better at outpacing skepticism over handheld devices guiding decisions and suggesting treatment relating to health care. The most recent example is an app that promises to identify one of the key symptoms of ear infections in kids.

The Associated Press reports that researchers at the University of Washington are close to finalizing an app that would allow a parent to assess whether or not their child has an ear infection using their phone, some paper, and some soft noises. A small piece of paper is folded into a funnel shape and inserted into the ear canal to focus the app's sounds (which resemble bird chirps) toward the child’s ear. The app measures sound waves bouncing off the eardrum. If pus or fluid is present, the sound waves will be altered, indicating a possible infection. The parent would then receive a text from the app notifying them of the presence of buildup in the middle ear.

The University of Washington tested the efficacy of the app by evaluating roughly 50 patients scheduled to undergo ear surgery at Seattle Children’s Hospital. The app was able to identify fluid in patients' ears about 85 percent of the time. That’s roughly as well as traditional exams, which involve visual identification as well as specialized acoustic devices.

While the system looks promising, not all cases of fluid in the ear are the result of infections or require medical attention. Parents would need to evaluate other symptoms, such as fever, if they intend to use the app to decide whether or not to seek medical attention. It may prove most beneficial in children with persistent fluid accumulation, a condition that needs to be monitored over the course of months when deciding whether a drain tube needs to be placed. Checking for fluid at home would save both time and money compared to repeated visits to a physician.

The app does not yet have Food and Drug Administration (FDA) approval and there is no timetable for when it might be commercially available. If it passes muster, it would join a number of FDA-approved “smart” medical diagnostic tools, including the AliveKor CardiaBand for the Apple Watch, which conducts EKG monitoring for heart irregularities.

[h/t WGRZ]

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