Space

The atmosphere of Jupiter greatly surprised scientists

NASA Juno mission has surpassed everythingpossible expectations. When she arrived in Jupiter last July after a five-year journey, this probe became the farthest solar powered object on Earth and also flew faster than any other human-made object. The probe's flight path passes closer to the thunderstorm gas giant than any devices that have been there before. And this is the first spacecraft to pass by the mysterious poles of Jupiter and find out, contrary to most assumptions, that they are blue and do not have bands characteristic of the planet.

Last August, Juno flew over Jupiterand collected data that scientists have been deciphering since. Today, two works have been published on the topic of Jupiterian auroras, atmosphere, magnetic and gravitational fields. The atmospheric dynamics of Jupiter is not only smaller than it was supposed, it resembles the Earth - it is much more complicated and changeable. To fully understand Jupiter, a single probe may be extremely insufficient. Fortunately, Juno is doing a good job.

It’s worth starting with the upper atmosphere and polarthe radiance of Jupiter. Scientists already knew that the polar lights of Jupiter make the northern lights familiar to us a dim flicker: they are hundreds of times more energetic and cover a larger area than the entire planet Earth. Juno uses several tools to study the energy particles of these auroras and the physics that controls their dynamics. And if the data from the first rendezvous allow us to draw certain conclusions, the auroras of Jupiter are very different from the earth.

“I really want to interpret what I saw onto another planet, based on Earth, ”says Jack Connerney, an astrophysicist at the Space Center. Goddard at NASA. "Until the last week, in our Jupiter aurora models, electrons went in the wrong direction."

On Earth, the electrons of the planet’s magnetic fieldexcited by the solar wind, and then sent to the poles, where they fly into other atoms and molecules, while emitting a characteristic glow. On Jupiter, as the Juno instruments discovered, the electrons are actually excited, leaving the polar regions.

In addition to this, everything indicates that planetologists generally misjudged the atmospheric dynamics of Jupiter.

“Scientists believed that the main source of energythere will be sun in the atmosphere, ”says Scott Bolton, Juno’s lead researcher and lead author of another work. "Therefore, they suggested that as soon as we descend below sunlight, the particles will be simple and well distinguishable."

But everything turned out to be wrong: particles of the atmosphere of Jupiter are as diverse and lined as the famous striped exterior of the planet. Of particular interest is the equatorial ammonia belt, which extends hundreds of kilometers down to the core of the planet - as far as the Juno tool could see. Based on the most current models of the atmosphere of Jupiter, this should not be at all.

Especially great activity was distinguished by the deep layers of the atmosphere of Jupiter: the magnetic and gravitational fields that the probe plans to map.

“If Jupiter was just big and spinningwith a gas ball, there shouldn’t be any strange harmonics in its gravitational field, ”says Connerney. But Jupiter’s gravity is heterogeneous, which may indicate deep convection - drops deep in Jupiter can lead to gravitational fluctuations in the same way that drops in atmospheric pressure change the weather on Earth. Jupiter’s magnetic field also turned out to be more geographically variable than scientists expected.

The Juno team still does not understand whyJupiter’s atmosphere is so disorganized, although Connerney dares to suggest that all fluctuations may be due to deep convection expressed in the gravitational field, which also leads to uneven magnetic field. “Looking back, we wonder why we thought everything would be simple and boring,” says Bolton.

A detailed understanding of Jupiter’s atmosphere mayhelp scientists understand some of the strangest features of the earth. Bolton compares Jupiter’s equatorial ammonia with the tropical zone around Earth’s own equator. “The concept we have on Earth is that the strip is developing because the air has an ocean that can be bounced off,” says Bolton. “But Jupiter doesn’t, so why does everything look the same there? Perhaps we do not understand something fundamental in the atmosphere. Perhaps our assumptions about the Earth were wrong. ”

The same information transfer can be applied toEarth’s magnetic field, which is difficult to study because it is generated deep beneath the earth’s crust and is partially covered by random deposits of iron. Jupiter has no crust and no additional magnets to collect data. For the first time we have the opportunity to look at a real magnetic dynamo. Maybe we should start with Jupiter.

All these discoveries challenge our understanding.space - and not just because of the results. Usually, scientists first send a probe to the planet, and after it - an orbiter equipped with all the gadgets for the data that the probe will collect. Our idea of ​​how Jupiter and the giant planets are structured over the past few decades was too simple.

And that means we need more missions in the style of "Juno" - with a large number of orbits that will allow us to make a complete map of the planet. It is fortunate that this probe coped with its task. It's only the beginning.