Juno, a large 3.6 tons of ship powered by solar energy will, for the first time, brushing the poles and the Jovian equator. Its 9 instruments will penetrate the thick cover to the heart of Jupiter, the largest planet in our solar system.
What are the great mysteries of Jupiter?
scientists believe Jupiter was the first planet in the solar system to form, just after the sun, there are 4.6 billion years, but do not know how exactly. During his training, they assume it has captured more than half of the gas and dust that swirled around our young star, keeping it in a sample of this primordial cloud that later gave birth to all other solar system bodies . As the sun, it is largely composed of hydrogen (90%) and helium but also contains water and ammonia, elements left after formation of the sun. Juno probe will also examine more closely the famous Great Red Spot of Jupiter that has continued to intrigue astronomers. This is a gigantic storm, 12,000 km wide. That is to say, it is as vast as once the Earth! The winds are blowing at over 700 km / h.
the probe will also look at the gigantic aurora six thousand times more intense than that which can be observed on Earth, present at the poles of the giant gas. On Earth, these color explosions occasionally occur when charged flashes of particles (electrons, ions) are projected in space by powerful solar flares. These particles interact with the Earth’s magnetic field, which causes their acceleration toward Earth. They come then excite atmospheric molecules that emit light when deexcite. On Jupiter, the aurora are independent of the solar wind. They are fed constantly by particles spewed by its volcanic moon Io. Accelerated through the strong magnetic field of the planet, these particles produce spirals of light that constantly illuminate its poles.
What does it teach us this mission?
Like the other giant planets (Saturn, Uranus and Neptune), Jupiter probably has no solid surface. It consists mainly of hydrogen and helium, present in gaseous form in the atmosphere. More you sink under the Jovian clouds, the more pressure and temperature rise, so that hydrogen gradually becomes fluid and “metallic”. The movements of this conductive layer are the cause of the huge magnetic field of Jupiter . At the heart of it – where the temperature exceeds 20,000 ° C and the pressure reaches 40 million terrestrial atmospheres – perhaps hides a fluid or solid core. This is what will, among others, to determine the probe. The latter will map its powerful gravitational and magnetic fields to determine its internal structure, will measure the amount of water and ammonia in the lower atmosphere and also observe the northern lights, says NASA. Juno will “of e a great step to understand how giant planets form and the role they play in the formation and organization of the rest of the star systems ” like ours, adds the space agency. The data collected will also shed new light on the conditions in our early solar system, when the planet was in training.
How to determine the nature of the heart of Jupiter?
“ We do not know if Jupiter has or not a core ,” notes Tristan Guillot, head of research at the French National Centre for scientific research (CNRS), which participates the Juno mission. This is in particular measuring the amounts of water and ammonia in the Jovian atmosphere as “ this and that the origins of this giant planet and the solar system will be elucidated ,” said the Nasa.
Where Juno does fly by Jupiter?
His first two revolutions will last about 54 days and then from October 2016 the ship will fit in an orbit of 14 days, brushing successively the two poles. Since Jupiter rotates on itself in less than ten hours, Juno will go over different regions with each rotation, covering the entire planet when it has achieved the 34 orbits planned for the mission before dive into Jupiter’s atmosphere where it will be destroyed. “ Never a ship will be approached as close to Jupiter: barely 10,000 kilometers above the poles and 5,000 km above the equator “, says Philippe Zarka, CNRS research director and scientists from the Juno mission. “ If the planet was the size of a basketball, the probe is approaching in less than a centimeter “, he said.
What are the risks to approach as close to the giant planet?
the Jovian magnetic field is nearly 20,000 times more powerful than that of Earth and the planet is surrounded by a belt very strong radiation equivalent to one hundred million radiology examinations a dentist for a year, according to NASA scientists. To protect themselves, Juno is equipped with a titanium solid shield around its electronic equipment and instruments, a trip computer and electric wiring. Weighing 172 kilos, this vault will reduce radiation exposure 800 times compared to the unprotected part.
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