Jupiter is not just the largest and most massive planet that is part of our solar system. He is a record holder in many ways. So, Jupiter has the most powerful magnetic field among the planets, radiates in the x-ray range, and has an extremely complex atmosphere. Planetologists show great interest in this planet, since it is difficult to overestimate the role of Jupiter in the history of the solar system, as well as in its present and future.
The Juno spacecraft, which reached a giant planet in 2016 and is currently carrying out a research program in orbit near Jupiter, is designed to help scientists solve many of its mysteries.
Mission start
The preparation of the expedition of this automatic probe to Jupiter was carried out by NASA as part of the New Frontiers program, focused on the comprehensive study of several objects of the solar system of particular interest. Juno became the second mission in the framework of this project. It started on August 5, 2011, and having spent almost five years en route, on July 5, 2016 it successfully entered orbit around Jupiter.
The name of the station, which went to a planet bearing the name of the supreme deity of Roman mythology, was chosen not just in honor of the wife of the “king of the gods”: it has a certain connotation. According to one myth, only Juno could penetrate the shroud of clouds with which Jupiter enveloped his unseemly deeds. Assigning the name of Juno to the spacecraft, the developers thereby identified one of the main objectives of the mission.
Probe tasks
Planetologists have many questions for Jupiter, and the answers to them depend on the fulfillment of the scientific tasks assigned to the automatic station. Depending on the object of study, these tasks can be combined into three main complexes:
- The study of the Jovian atmosphere. The refined composition, structure, temperature characteristics, dynamics of gas flows in the deep layers of the atmosphere, located below visible clouds, are all extremely interested in scientists, authors of the Juno scientific program. The spacecraft, justifying the name given to it, looks with its devices further than it has been possible so far.
- The study of the magnetic field and magnetosphere of the giant. At a depth of more than 20 thousand km, at tremendous pressures and temperatures, huge masses of hydrogen are in a state of liquid metal. The currents in it generate a powerful magnetic field, and knowledge of its features is important for clarifying the structure of the planet and the history of its formation.
- The study of the structure of the gravitational field is also necessary for planetologists to build a more accurate model of the structure of Jupiter. It will make it possible to more confidently judge the mass and size of the deepest layers of the planet, including its solid inner core.
Scientific equipment "Juno"
The design of the spacecraft provides for the carrying of a number of devices designed to solve the above problems. These include:
- Magnetometric complex MAG, composed of two magnetometers and a star sensor.
- Space segment of equipment for gravitational measurements Gravity Science. The second segment is located on Earth, the measurements themselves are carried out using the Doppler effect.
- MWR microwave radiometer for studying the atmosphere at great depths.
- UVS spectrograph for studying the structure of Jupiter’s auroras.
- JADE tool for fixing the distribution of low-energy charged particles in auroras.
- JEDI high energy ion and electron distribution detector.
- Detector of plasma and radio waves in the magnetosphere of the planet Waves.
- JIRAM infrared camera.
- The JunoCam optical range camera, housed at the Juno, is primarily for demonstration and educational purposes for the general public. This camera does not have special scientific tasks.
Design Features and Specifications of Juno
The spacecraft had a launch weight of 3625 kg. Of these, only about 1600 kg falls on the share of the station itself, the rest of the mass - fuel and oxidizer - are consumed during the mission. In addition to the main engine, the device is equipped with four modules of orientation engines. The probe is powered by three 9-meter solar panels. The diameter of the apparatus, excluding their length, is 3.5 meters.
The total power of solar cells in orbit in Jupiter by the end of the mission should be at least 420 watts. In addition, the Juno is equipped with two lithium-ion batteries for power at a time when the station is in the shadow of Jupiter.
The developers took into account the special conditions in which "Juno" will have to work. The characteristics of the spacecraft are adapted to the conditions of a long stay within the powerful radiation belts of a giant planet. The vulnerable electronics of most instruments are housed in a special cubic titanium compartment protected from radiation. The thickness of its walls is 1 cm.
Unusual "passengers"
The station carries on board three aluminum figures of Lego-style men, depicting the ancient Roman gods Jupiter and Juno, as well as the discoverer of the planet's moons - Galileo Galilei. These "passengers", as the mission staff explain, went to Jupiter to draw the attention of the younger generation to science and technology, to interest children in space exploration.
The Great Galileo is present on board and on the portrait, placed on a special plate provided by the Italian Space Agency. It also contains a fragment of a letter written by a scientist in early 1610, where he first mentions the observation of satellites of the planet.
Portraits of Jupiter
The JunoCam camera, although it does not carry a scientific burden, was able to truly glorify the Uno spacecraft for the whole world. Photos of the giant planet, taken with a resolution of up to 25 km per pixel, are staggering. Never before have people seen the magnificent and formidable beauty of Jupiter's clouds in such detail.
Latitudinal cloud belts, hurricanes and whirlwinds of a powerful Jupiterian atmosphere, a gigantic Big Red Spot anticyclone - all this was captured by the Juno Optical Camera. The images of Jupiter from the spacecraft made it possible to see the polar regions of the planet inaccessible to telescopic observations from the Earth and near-Earth orbit.
Some scientific findings
The mission has achieved impressive scientific success. Here are just a few of them:
- The asymmetry of the gravitational field of Jupiter is established, caused by the distribution of atmospheric flows. It turned out that the depth to which these bands extend, visible on the disk of Jupiter, reaches 3000 km.
- A complex atmospheric structure of the polar regions has been discovered, characterized by active turbulent processes.
- Measurements of the magnetic field. It turned out to be an order of magnitude higher than the most powerful earthly magnetic fields of natural origin.
- A three-dimensional map of the Jovian magnetic field is constructed.
- Detailed pictures of the auroras were obtained.
- New data on the composition and dynamics of the Great Red Spot have been obtained.
These are far from all the achievements of Juno, but scientists hope to get even more information with its help, because the mission is still ongoing.
The future of Juno
It was originally planned that the mission will work until February 2018. Then NASA decided to extend the station’s stay near Jupiter until July 2021. All this time, she will continue to collect and send new data to Earth, as well as continue photographing Jupiter.
At the end of the mission, the station will be sent to the atmosphere of the planet, where it will burn. Such a finale is intended to avoid a future fall on any of the major satellites and the possible contamination of its surface by Earth microorganisms from Juno. The spacecraft still has a lot of time ahead, and scientists are counting on the rich scientific “harvest” that the Juno will bring them.