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18 septembre 2013 3 18 /09 /septembre /2013 11:18

On August 25, 2012 "Voyager 1" became the first human-made object to leave the inner solar system and enter interstellar space, traveling "farther than anyone, or anything, in history". [1] TOSHIBA Satellite L750-ST5N02 laptop keyboard

In April 2013, Voyager 1 became the farthest human-made object sent from the Earth. On 15 June 2012, scientists at NASA reported that Voyager 1 might be very close to entering interstellar space and becoming the first manmade object to leave the inner Solar System.[2][3] HP Pavilion DV6-1160ed laptop keyboard

On September 12, 2013, NASA announced that Voyager 1 had entered a previously unstudied region of space known as interstellar space on August 25, 2012, making it the first human-made object to do so.[4][5][6][7][8][9] As of 2013, the probe was moving with a relative velocity to the Sun of 17 kilometres per second (11 mi/s).[10] SONY VAIO VGN-FS195VP laptop keyboard

 The amount of power available to the probe has decreased over time, and will be no longer able to power any single instrument by 2025.

Both of the Voyager missions into outer space have gathered large amounts of data about the gas giants of the solar system, and their orbiting satellites, about which little had been previously known. IBM ThinkPad T42 laptop keyboard

In addition, the trajectories of the two spacecraft have been used to place limits on the existence of any hypotheticaltrans-Neptunian planets.

Data and photographs collected by the Voyagers’ cameras, magnetometers, and other instruments revealed previously unknown details about each of the giant planets and their moons. DELL Inspiron N4050 laptop keyboard

Close-up images from the spacecraft charted Jupiter’s complex cloud forms, winds, and storm systems and discovered volcanic activity on its moon Io. Saturn’s rings were found to have enigmatic braids, kinks, and spokes and to be accompanied by myriad “ringlets.” At Uranus Voyager 2discovered a substantial magnetic field around the planet and 10 additional moons. TOSHIBA PK13CW10200 laptop keyboard

Its flyby of Neptune uncovered three complete rings and six hitherto unknown moons as well as a planetary magnetic field and complex, widely distributed auroras.

The Voyager space probes were originally conceived as part of the Mariner program, and they were thus named Mariner 11 and Mariner 12, respectively. HP Pavilion dv6-2143ez laptop keyboard

They were then moved into a separate program named Mariner Jupiter-Saturn, later renamed the Voyager Program because it was thought that the design of the two space probes had progressed sufficiently above those of the Mariner family that they merited a separate name.[11]SONY N860-7676-T101 laptop keyboard

The Voyager Program is essentially a scaled-back version of the program "Grand Tour" of the Outer Planets planned during the late 1960s and early 70s. Gary Flandro, an aerospace engineer at the Jet Propulsion Laboratory on the study team, discovered that the alignment of the outer planets would make it possible to use gravitational assists from Jupiter to go to Saturn, HP Pavilion dv6-2124eo laptop keyboard

and thence and on to Uranus and Neptune. The plan of the "Grand Tour" was to send several pairs of probes to fly by all the outer planets, including Pluto, along various trajectories, including Jupiter-Saturn-Pluto and Jupiter-Uranus-Neptune.

The major plans for the "Grand Tour" were dramatically scaled back because of lack of money appropriated by Congress. DELL Inspiron MINI 1010 laptop keyboard

In the end, the Voyager Program fulfilled many of the flyby objectives of the "Grand Tour" excepting any mission to Pluto, and dual missions to Uranus and Neptune.

Of the two space probes of the Voyager ProgramVoyager 2 was launched first. Its trajectory was designed to take advantage of an unusual alignment of the planets (that occurs once every 177[ years) SONY VAIO VGN-CR12GH laptop keyboard

that allowed one space probe to fly by Jupiter, Saturn, Uranus, and Neptune, if everything went well. Of course, in case of a serious malfunction, such as in all of the space probe's radio transmitters or receivers, then that would have been the end of the long mission (to four planets), since there was not a second space probe to fill the gap.  Lenovo 04W2236 laptop keyboard

That was the gamble that NASA and the JPL were forced to take.

Voyager 1 was launched after its sister probe, but along a shorter and faster trajectory that sent it to Jupiter and Saturn sooner—but at the cost of not visiting any more of the outer planets. Voyager 1 also had the high-priority mission of making a close fly-by of the Saturnian moon Titan, HP SG-46100-XUA laptop keyboard

which was known to be quite large and to possess a dense atmosphere very much worth studying.[12]

During the 1990s, Voyager 1 overtook the slower deep-space probes Pioneer 10 and Pioneer 11 to become the most distant manmade object from Earth, a record that it will keep for the foreseeable future. Lenovo 04W2236 laptop keyboard

Even the faster (at its launch) New Horizons space probe will not pass it, since the final speed of New Horizons (after maneuvering within the solar system) will be less than the current speed of Voyager 1.

Voyager 1 and Pioneer 10 are the most widely separated manmade objects anywhere, since they are traveling in roughly opposite directions from the Solar System. HP Pavilion DV7-3060us laptop keyboard

Periodic contact has been maintained with Voyager 1 and Voyager 2 to monitor conditions in the outer expanses of the Solar System. The radioactive power sources of both spacecraft were still producing significant amounts of electric power as of 2012, keeping them operational, and it is hoped that this will allow theheliopause of the Solar System to be located and investigated. TOSHIBA Satellite L505-S6959 laptop keyboard

In late 2003 Voyager 1 began sending data that seemed to indicate it had crossed the termination shock, but interpretations of these data are in dispute, and it was later believed that the termination shock was crossed in December 2004. The heliopause remains an unknown distance ahead.  HP Probook 4710S Laptop Keyboard

On December 10, 2007, instruments on board Voyager 2 sent data back to Earth indicating that the solar system is asymmetrical. It has also reached the termination shock, about 10 billion miles from where Voyager 1 first crossed it, and is traveling outward at roughly 3.3 AU per year. HP G42-164LA Laptop Keyboard

In August 2009 Voyager 1 was over 16.5 terameters (16.5×1012 meters, or 16.5×109 km, 110.7 AU, or 10.2 billion miles) from the Sun, and thus had entered theheliosheath region between the solar wind's termination shock and the heliopause (the limit of the solar wind). Beyond the heliopause is the bow shock of theinterstellar medium, SONY VAIO VGN-FS315M Laptop Keyboard

beyond which the probes enter interstellar space and the Sun's gravitational influence on them is exceeded by that of the Milky Way galaxyin general. At the heliopause, light from the Sun takes over 16 hours to reach the probe.

By December 2010 Voyager 1 had reached a region of space where there was no net velocity of the solar wind. ACER Aspire One D150-1920 Laptop Keyboard

At this point, the wind from the Sun may be canceled out by the interstellar wind. It does not appear that the spacecraft has yet crossed the heliosheath into interstellar space.[13]

On June 10, 2011, scientists studying the Voyager data noticed what may be giant magnetic bubbles located in the heliosphere, HP Envy 15 Laptop Keyboard

the region of our solar system that separates us from the violent solar winds of interstellar space. The bubbles, scientists theorize, form when the magnetic field of the Sun becomes warped at the edge of our Solar System.

The Voyager spacecraft weighs 773 kilograms. Of this, 105 kilograms are scientific instruments.[15] HP Mini 210-1109TU Laptop Keyboard

The identicalVoyager spacecraft use three-axis-stabilized guidance systems that use gyroscopic and accelerometer inputs to theirattitude control computers to point their high-gain antennas towards the Earth and their scientific instruments pointed towards their targets, sometimes with the help of a movable instrument platform for the smaller instruments and theelectronic photography system. HP 519265-001 Laptop Keyboard

The diagram at the right shows the high-gain antenna (HGA) with a 3.66 meter diameter dish attached to the hollowdecagonal electronics container. There is also a spherical tank that contains the hydrazine monopropellant fuel.

The Voyager Golden Record is attached to one of the bus sides. SAMSUNG N140 Laptop Keyboard

The angled square panel to the right is the optical calibration target and excess heat radiator. The three radioisotope thermoelectric generators (RTGs) are mounted end-to-end on the lower boom.

The scan platform comprises: the Infrared Interferometer Spectrometer (IRIS) (largest camera at top right); the Ultraviolet Spectrometer (UVS) just above the UVS;

 HP G42-164LA Laptop Keyboard

the two Imaging Science Subsystem (ISS) vidicon cameras to the left of the UVS; and the Photopolarimeter System (PPS) under the ISS.

Only five investigation teams are still supported, though data is collected for two additional instruments.[16] The Flight Data Subsystem (FDS) and a single eight-track digital tape recorder (DTR) provide the data handling functions.  Lenovo 3000 Y500 Laptop Keyboard

The FDS configures each instrument and controls instrument operations. It also collects engineering and science data and formats the data for transmission. The DTR is used to record high-rate Plasma Wave Subsystem (PWS) data. The data is played back every six months. Lenovo ThinkPad Edge E520 Laptop Keyboard

The Imaging Science Subsystem, made up of a wide angle and a narrow angle camera, is a modified version of the slow scan vidicon camera designs that were used in the earlier Mariner flights. The Imaging Science Subsystem consists of two television-type cameras, each with eight filters in a commandable Filter Wheel mounted in front of the vidicons. TOSHIBA NSK-TBD01 Laptop Keyboard

One has a low resolution 200 millimeter wide-angle lens with an aperture of f/3 (the wide angle camera), while the other uses a higher resolution 1.500 meter narrow-angle f/8.5 lens (the narrow angle camera).

Unlike the other onboard instruments, the operation of the cameras for visible light is not autonomous, ACER Aspire 5930 Laptop Keyboard

but rather it is controlled by an imaging parameter table contained in one of the on-board digital computers, the Flight Data Subsystem (FDS). More recent space probes, since about 1990, usually have completelyautonomous cameras.

The computer command subsystem (CCS) controls the cameras. HP G71-343US Laptop Keyboard

The CCS contains fixed computer programs such as command decoding, fault detection, and correction routines, antenna pointing routines, and spacecraft sequencing routines. This computer is an improved version of the one that was used in the Viking orbiter.[19]The hardware in both custom-built CCS subsystems in the Voyagers is identical. HP Pavilion G7-1150US Laptop Keyboard

There is only a minor software modification for one of them that has a scientific subsystem that the other lacks.

The Attitude and Articulation Control Subsystem (AACS) controls the spacecraft orientation (its attitude). It keeps the high-gain antenna pointing towards the Earth, controls attitude changes, and points the scan platform. The custom-built AACS systems on both craft are identical. HP Pavilion DV7-3065dx Laptop Keyboard

It has been erroneously reported[citation needed] on the Internet that the Voyager space probes were controlled by a version of the RCA 1802 (RCA CDP1802 "COSMAC"microprocessor), but such claims are not supported by the primary design documents. The CDP1802 microprocessor was used later in the Galileo space probe, which was designed and built years later.  HP G62-a20SQ laptop keyboard

The digital control electronics of the Voyagers were based on RCA CD4000 radiation-hardened, silicon-on-sapphire (SOS) custom-made integrated circuit chips, combined with standard transistor-transistor logic (TTL) integrated circuits.

The uplink communications are executed via S-band microwave communications. TOSHIBA Satellite A300-1BZ laptop keyboard

The downlink communications are carried out by an X-band microwave transmitter on board the spacecraft, with an S-band transmitter as a back-up. All long-range communications to and from the two Voyagers have been carried out using their 3.67-meter high-gain antennas. SONY VAIO VGN-FZ19VN laptop keyboard

Because of the inverse-square law in radio communications, the digital data rates used in the downlinks from the Voyagers has been continually decreasing the farther that they get from the Earth. For example, the data rate used from Jupiter was about 115,000 bits per second. SONY VAIO VGN-FS115ZR laptop keyboard

That was halved at the distance of Saturn, and it has gone down continually since then. Some measures were taken on the ground along the way to reduce the effects of the inverse-square law. In between 1982 and 1985, the diameters of the three main parabolic dish antennas of the Deep Space Network was increased from 240 feet to 270 feet, dramatically increasing their areas for gathering weak microwave signals. HP Pavilion dv6-3230us laptop keyboard

Then between 1986 and 1989, new techniques were brought into play to combine the signals from multiple antennas on the ground into one, more powerful signal, in a kind of an antenna array. This was done at Goldstone, California, Canberra, and Madrid using the additional dish antennas available there. COMPAQ Presario CQ50-210US laptop keyboard

Also, in Australia, the Parkes Radio Telescope was brought into the array in time for the fly-by of Neptune in 1989. In the United States, the Very Large Array in New Mexico was brought into temporary use along with the antennas of the Deep Space Network at Goldstone. Using this new technology of antenna arrays helped to compensate for the immense radio distance from Neptune to the Earth. HP 590527-001 laptop keyboard

Electrical power is supplied by three MHW-RTG radioisotope thermoelectric generators (RTGs). They are powered by plutonium-238 (distinct from the Pu-239 isotope used in nuclear weapons) and provided approximately 470 W at 30 volts DC when the spacecraft was launched. Plutonium-238 decays with a half-life of 87.74 years,[20] TOSHIBA Satellite L655D-12L laptop keyboard

so RTGs using Pu-238 will lose a factor of 1−0.5{1/87.74} = 0.79% of their power output per year.

In 2011, 34 years after launch, such an RTG would inherently produce 470 W × 2−(34/87.74) ≈ 359 W, about 76% of its initial power. Additionally, the thermocouples that convert heat into electricity also degrade, reducing available power below this calculated level. ASUS K030662M2 laptop keyboard

By 7 October 2011 the power generated by Voyager 1 and Voyager 2 had dropped to 267.9 W and 269.2 W respectively, about 57% of the power at launch. The level of power output was better than pre-launch predictions based on a conservative thermocouple degradation model. As the electrical power decreases, spacecraft loads must be turned off, eliminating some capabilities. HP Pavilion dv6-2155dx laptop keyboard

The Voyager primary mission was completed in 1989, with the close flyby of Neptune by Voyager 2. The Voyager Interstellar Mission (VIM) is a mission extension, which began when the two spacecraft had already been in flight for over 12 years.[21]The Heliophysics Division of the NASA Science Mission Directorate conducted a Heliophysics Senior Review in 2008.  HP Pavilion dv6-3015tx laptop keyboard

The panel found that the VIM "is a mission that is absolutely imperative to continue" and that VIM "funding near the optimal level and increased DSN (Deep Space Network) support is warranted."[22]

As of the present date, the Voyager 2 and Voyager 1 scan platforms, including all of the platform instruments, have been powered down. ACER TravelMate 8215WLMi laptop keyboard

The ultraviolet spectrometer (UVS)[23] on Voyager 1 was active until 2003, when it too was deactivated. Gyro operations will end in 2015 for Voyager 2 and 2016 for Voyager 1. Gyro operations are used to rotate the probe 360 degrees six times per year to measure the magnetic field of the spacecraft, which is then subtracted from themagnetometer science data.  HP Pavilion dv6-2165tx laptop keyboard

The two Voyager spacecraft continue to operate, with some loss in subsystem redundancy, but retain the capability of returning scientific data from a full complement of Voyager Interstellar Mission (VIM) science instruments.

Both spacecraft also have adequate electrical power and attitude control propellant to continue operating until around 2025,  SONY VAIO VGN NR298E laptop keyboard

after which there may not be available electrical power to support science instrument operation. At that time, science data return and spacecraft operations will cease.

The Voyager 2 spacecraft is a 722 kg (1,590 lb) space probe launched by NASA on August 20, 1977 to study the outerSolar System and eventually interstellar space. SONY N860-7676-T101 laptop keyboard

It was actually launched before Voyager 1, but Voyager 1 moved faster and eventually passed it. It has been operating for 36 years and 26 days as of 15 September 2013; the spacecraft still receives and transmits data via the Deep Space Network.[4] At a distance of 101.75 AU (1.522×1010 km) as of 15 September 2013 from earth,[5] SONY VAIO PCG-FR415S laptop keyboard

 it is one of the most distant manmade objects (along with Voyager 1, Pioneer 10 and Pioneer 11). {note: for current distance see.[5]} Voyager 2 is part of the Voyager program with its identical sister craft Voyager 1, and is in extended mission, tasked with locating and studying the boundaries of the Solar System, including the Kuiper belt, the heliosphere and interstellar space.  Lenovo Thinkpad T520 laptop keyboard

The primary mission ended December 31, 1989 after encountering the Jovian system in 1979, Saturnian system in 1980, Uranian system in 1986, and the Neptunian system in 1989. It is still the only spacecraft to have visited the two outer giant planets Uranusand Neptune. The probe is now moving at a velocity of 15.428 km/second.IBM Lenovo Thinkpad X200 laptop keyboard

Conceived in the 1960s, a Planetary Grand Tour proposal to study the outer planets, prompted NASA to begin work on a mission in the early 1970s. The development of the interplanetary probes coincided with an alignment of the planets, making possible a mission to the outer Solar System by taking advantage of the then-new technique of gravity assist. DELL Inspiron N4050 laptop keyboard

It was determined that utilizing gravity assists would enable a single probe to visit the four gas giants (Jupiter,Saturn, Uranus, and Neptune) while requiring a minimal amount of propellant and a shorter transit duration between planets. Originally, Voyager 2 was planned as Mariner 12 of the Mariner program; HP G72-227WM laptop keyboard

however, due to congressional budget cuts, the mission was scaled back to be a flyby of Jupiter and Saturn, and renamed the Mariner Jupiter-Saturn probes. As the program progressed, the name was later changed to Voyager as the probe designs began to differ greatly from previous Mariner missions.[7] HP AEAT8TPU017 Laptop Keyboard

Upon a successful flyby of the Saturnian moon Titan, by Voyager 1Voyager 2 would get a mission extension to send the probe on towards Uranus and Neptune, ultimately realizing the vision of the Planetary Grand Tour.

Each Voyager space probe carries a gold-plated audio-visual disc in the event that either spacecraft is ever found by intelligent life-forms from other planetary systems.[9]  HP pavilion DV7-1000 Laptop Keyboard

 The discs carry photos of the Earth and its lifeforms, a range of scientific information, spoken greetings from the people (e.g. the Secretary-General of the United Nations and the President of the United States, and the children of the Planet Earth) and a medley, "Sounds of Earth", that includes the sounds of whales, a baby crying, waves breaking on a shore, and a variety of music. Compaq Presario CQ57 Series Laptop Keyboard

Constructed by the Jet Propulsion Laboratory (JPL), Voyager 2 included 16 hydrazine thrusters, three-axis stabilization, gyroscopes and celestial referencing instruments (Sun sensor/Canopus Star Tracker) to maintain pointing of the high-gain antenna toward Earth. Collectively these instruments are part of the Attitude and Articulation Control Subsystem (AACS) along with redundant units of most instruments and 8 backup thrusters. SONY Vaio PCG-K35 Laptop Keyboard

The spacecraft also included 11 scientific instruments to study celestial objects as it traveled through space.

Built with the intent for eventual interstellar travel, Voyager 2 included a large, 3.7 m (12 ft) parabolic, high-gain antenna (see diagram) to transceive data via the Deep Space Network on the Earth. HP G42T-200 CTO Laptop Keyboard

Communications are conducted over the S-band (about 13 cm wavelength) and X-band (about 3.6 cm wavelength) providing data rates as high as 115.2 kilobits per second at the distance of Jupiter, and then ever-decreasing as the distance increased, because of the inverse-square law. Lenovo ThinkPad Edge E520 Laptop Keyboard

When the spacecraft is unable to communicate with Earth, the Digital Tape Recorder (DTR) is able to record up to 62,500-kilobytes of data to later transmit when communication is reestablished.

The spacecraft was built with 3 Multihundred-Watt radioisotope thermoelectric generators (MHW RTG). Each RTG includes 24 pressed plutonium oxide spheres and provides enough heat to generate approximately 157 watts of power at launch. SONY 147977821 Laptop Keyboard

Collectively, the RTGs supply the spacecraft with 470 watts at launch and will allow operations to continue until at least 2020.

The closest approach to Jupiter occurred on July 9, 1979. It came within 570,000 km (350,000 mi) of the planet's cloud tops.[20] It discovered a few rings around Jupiter, as well as volcanic activity on the moon Io.  Lenovo ThinkPad Edge E520 Laptop Keyboard

The Great Red Spot was revealed as a complex storm moving in a counterclockwise direction. An array of other smaller storms and eddies were found throughout the banded clouds.

Discovery of active volcanism on Io was easily the greatest unexpected discovery at Jupiter. It was the first time active volcanoes had been seen on another body in the Solar System. SONY Vaio PCG-K35 Laptop Keyboard

Together, the Voyagers observed the eruption of nine volcanoes on Io, and there is evidence that other eruptions occurred between the two Voyager fly-bys.

The moon Europa displayed a large number of intersecting linear features in the low-resolution photos from Voyager 1. At first, scientists believed the features might be deep cracks, caused by crustal rifting or tectonic processes. TOSHIBA NSK-TAJ01 Laptop Keyboard

The closer high-resolution photos from Voyager 2, however, left scientists puzzled: The features were so lacking in topographic relief that as one scientist described them, they "might have been painted on with a felt marker." SONY VAIO VGN-AR230G laptop keyboard

Europa is internally active due to tidal heating at a level about one-tenth that of Io. Europa is thought to have a thin crust (less than 30 km (19 mi) thick) of water ice, possibly floating on a 50-kilometer-deep (30 mile) ocean.

Two new, small satellites, Adrastea and Metis, were found orbiting just outside the ring. A third new satellite, Thebe, was discovered between the orbits ofAmalthea and Io. SONY VAIO VGN-AR670 laptop keyboard

While passing behind Saturn (as viewed from Earth), Voyager 2 probed Saturn's upper atmosphere with its radio link to gather information on atmospheric temperature and density profiles. Voyager 2 found that at the uppermost pressure levels (seven kilopascals of pressure), Saturn's temperature was 70 kelvins(−203 °C), HP Pavilion dv6-2030ev laptop keyboard


while at the deepest levels measured (120 kilopascals) the temperature increased to 143 K (−130 °C). The north pole was found to be 10 kelvins cooler, although this may be seasonal (see also Saturn Oppositions).

After the fly-by of Saturn, the camera platform of Voyager 2 locked up briefly, putting plans to officially extend the mission to Uranus and Neptune in jeopardy. HP Pavilion dv6-2030ev laptop keyboard

Fortunately, the mission's engineers were able to fix the problem (caused by an overuse that temporarily depleted its lubricant), and the Voyager 2probe was given the go-ahead to explore the Uranian system.

The closest approach to Uranus occurred on January 24, 1986, when Voyager 2 came within 81,500 kilometers (50,600 mi) of the planet's cloud tops. Compaq Presario CQ56-102SE laptop keyboard

Voyager 2 also discovered the moons Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Belinda, Perdita and Puck; studied the planet's unique atmosphere, caused by its axial tilt of 97.8°; and examined the Uranian ring system. TOSHIBA Satellite C655-SP6010L laptop keyboard

Uranus is the third largest (Neptune has a larger mass, but a smaller volume) planet in the Solar System. It orbits the Sun at a distance of about 2.8 billion kilometers (1.7 billion miles), and it completes one orbit every 84 Earth years. The length of a day on Uranus as measured by Voyager 2 is 17 hours, 14 minutes. HP 9J.NOL82.W01 laptop keyboard

Uranus is unique among the planets in that its axial tilt is about 90°, meaning that its axis is roughly parallel with, not perpendicular to, the plane of the ecliptic. This extremely large tilt of its axis is thought to be the result of a collision between the accumulating planet Uranus with another planet-sized body early in the history of the Solar System. FUJITSU Lifebook S7210 laptop keyboard

Given the unusual orientation of its axis, with the polar regions of Uranus exposed for periods of many years to either continuous sunlight or darkness, planetary scientists were not at all sure what to expect when observing Uranus.

Voyager 2 found that one of the most striking effects of the sideways orientation of Uranus is the effect on the tail of the planetary magnetic field SONY VAIO VGN-N38Z/W laptop keyboard

This is itself tilted about 60° from the Uranian axis of rotation. The planet's magneto tail was shown to be twisted by the rotation of Uranus into a long corkscrew shape following the planet. The presence of a significant magnetic field for Uranus was not at all known until Voyager's 2 arrival.

The radiation belts of Uranus were found to be of an intensity similar to those of Saturn. HP Pavilion DV6t-4000 laptop keyboard

The intensity of radiation within the Uranian belts is such that irradiation would "quickly" darken — within 100,000 years — any methane that is trapped in the icy surfaces of the inner moons and ring particles. This kind of darkening might have contributed to the darkened surfaces of the moons and the ring particles, which are almost uniformly dark gray in color. SONY VAIO VGN-N250E/B laptop keyboard

A high layer of haze was detected around the sunlit pole of Uranus. This area was also found to radiate large amounts of ultraviolet light, a phenomenon that is called "dayglow." The average atmospheric temperature is about 60 K (−350°F/−213°C). Surprisingly, the illuminated and dark poles, and most of the planet, exhibit nearly the same temperatures at the cloud tops. HP Pavilion dv6-2112sa Laptop Keyboard

The Uranian moon Miranda, the innermost of the five large moons, was discovered to be one of the strangest bodies yet seen in the Solar System. Detailed images from Voyager 2's flyby of Miranda showed huge canyons made from geological faults as deep as 20 kilometers (12 mi), terraced layers, and a mixture of old and young surfaces. COMPAQ Presario CQ60-201EP Laptop Keyboard

One hypothesis suggests that Miranda might consist of a reaggregation of material following an earlier event when Miranda was shattered into pieces by a violent impact.

All nine of the previously known Uranian rings were studied by the instruments of Voyager 2. These measurements showed that the Uranian rings are distinctly different from those at Jupiter and Saturn. HP Pavilion G7-1167DX Laptop Keyboard

The Uranian ring system might be relatively young, and it did not form at the same time that Uranus did. The particles that make up the rings might be the remnants of a moon that was broken up by either a high-velocity impact or torn up by tidal effects.

Voyager 2's closest approach to Neptune occurred on August 25, 1989.[22][23] HP AEUT5U00010 Laptop Keyboard

Since this was the last planet of our Solar System that Voyager 2 could visit, the Chief Project Scientist, his staff members, and the flight controllers decided to also perform a close fly-by of Triton, the larger of Neptune's two originally known moons, so as to gather as much information on Neptune and Triton as possible, regardless of what angle at which Voyager 2 would fly away from Neptune. DELL Inspiron 1750 Laptop Keyboard

This was just like the case of Voyager 1's encounters with Saturn and its massive moon Titan.

Through repeated computerized test simulations of trajectories through the Neptunian system conducted in advance, flight controllers determined the best way to route Voyager 2 through the Neptune-Triton system. HP Pavilion dv6-2112sa Laptop Keyboard

Since the plane of the orbit of Triton is tilted significantly with respect to the plane of the ecliptic, through mid-course corrections, Voyager 2 was directed into a path several thousand miles over the north pole of Neptune. At that time, Triton was behind and below (south of) Neptune (at an angle of about 25 degrees below the ecliptic), close to the apoapsis of its elliptical orbit. HP G62-147NR Laptop Keyboard

The gravitational pull of Neptune bent the trajectory of Voyager 2 down in the direction of Triton. In less than 24 hours, Voyager 2 traversed the distance between Neptune and Triton, and then observed Triton's northern hemisphere as it passed over its north pole. DELL NSK-DG101 Laptop Keyboard

The net and final effect on the trajectory of Voyager 2 was to bend its trajectory south below the plane of the ecliptic by about 30 degrees. Voyager 2 is on this path permanently, and hence, it is exploring space south of the plane of the ecliptic, measuring magnetic fields, charged particles, etc., there, and sending the measurements back to the Earth via telemetry.  HP Pavilion G6-1223TX Laptop Keyboard

While in the neighborhood of Neptune, Voyager 2 discovered the "Great Dark Spot", which has since disappeared, according to observations by the Hubble Space Telescope. Originally thought to be a large cloud itself, the "Great Dark Spot" was later hypothesized to be a hole in the visible cloud deck of Neptune. SONY VAIO VGN-FS550 Laptop Keyboard

Neptune's atmosphere consists of hydrogen, helium, and methane. The methane in Neptune's upper atmosphere absorbs the red light from the Sun, but it reflects the blue light from the Sun back into space. This is why Neptune looks blue.

With the decision of the International Astronomical Union to reclassify Pluto as a "plutoid" in 2008,  HP Pavilion dv6-2112sa Laptop Keyboard

the flyby of Neptune by Voyager 2 in 1989 became the point when every known planet in the Solar System had been visited at least once by a space probe.

Once its planetary mission was over, Voyager 2 was described as working on an interstellar mission, which NASA is using to find out what the Solar System is like beyond the heliosphere. HP 640436-001 Laptop Keyboard

 Voyager 2 is currently transmitting scientific data at about 160 bits per second. Information about continuing telemetry exchanges with Voyager 2 is available from Voyager Weekly Reports.

On November 30, 2006, a telemetered command to Voyager 2 was incorrectly decoded by its on-board computer—in a random error—as a command to turn on the electrical heaters of the spacecraft's magnetometer. TOSHIBA NSK-TBD01 Laptop Keyboard

These heaters remained turned on until December 4, 2006, and during that time, there was a resulting high temperature above 130 °C (266 °F), significantly higher than the magnetometers were designed to endure, and a sensor rotated away from the correct orientation. It has not been possible to fully diagnose and correct for the damage caused to the Voyager 2's magnetometer, although efforts to do so are proceeding.[25] TOSHIBA Satellite L755-SP5102CL Laptop Keyboard

On August 30, 2007, Voyager 2 passed the termination shock into the heliosheath, approximately 1billion miles (1.6billion km) closer to the Sun than Voyager 1 did.[26]This is due to the interstellar magnetic field of deep space. The southern hemisphere of the Solar System's heliosphere is being pushed in.[27] HP 640436-001 Laptop Keyboard

On April 22, 2010, Voyager 2 encountered scientific data format problems.[28] On May 17, 2010, JPL engineers revealed that a flipped bit in an on-board computer had caused the issue, and scheduled a bit reset for May 19.[29]

On May 23, 2010, Voyager 2 resumed sending science data from deep space after engineers fixed the flipped bit.[30] HP Pavilion G6-1223TX Laptop Keyboard

Currently research is being made into marking the area of memory with the flipped bit off limits or disallowing its use. The Low-Energy Charged Particle Instrument is currently operational, and data from this instrument concerning charged particles is being transmitted to Earth. This data permits measurements of the heliosheath and termination shock. HP Mini 110-3004tu Laptop Keyboard

There has also been a modification to the on-board flight software to delay turning off the AP Branch 2 backup heater for 1 year. It was scheduled to go off February 2, 2011 (DOY 033, 2011–033).

On July 25, 2012, Voyager 2 was traveling at 15.447 km/s relative to the Sun at about 99.13 astronomical units (1.4830×1010 km) from the Sun,[31] TOSHIBA Satellite M645-S4047 Laptop Keyboard

 at −55.29°declination and 19.888 h right ascension, and also at an ecliptic latitude of −34.0 degrees, placing it in the constellation Telescopium as observed from Earth.[32] This location places it deep in the scattered disc, and traveling outward at roughly 3.264 AU per year. It is more than twice as far from the Sun asPluto, DELL Inspiron N4050 laptop keyboard

and far beyond the perihelion of 90377 Sedna, but not yet beyond the outer limits of the orbit of the dwarf planet Eris.

On September 9, 2012, Voyager 2 was 99.077 AU (1.48217×1010 km; 9.2098×109 mi) from the Earth and 99.504 AU (1.48856×1010 km; 9.2495×109 mi) from the Sun; Lenovo ThinkPad Edge E520 laptop keyboard

and traveling at 15.436 km/s (34,530 mph) (relative to the Sun) and traveling outward at about 3.256 AU per year.[33] Sunlight takes 13.73 hours to get toVoyager 2. The brightness of the Sun from the spacecraft is magnitude -16.7.[33] Voyager 2 is heading in the direction of the constellation Telescopium.[33] SONY VAIO VGN-FS115Z laptop keyboard

 (To compare, Proxima Centauri, the closest star to our Sun, is about 4.2 light-years (or 2.65×105 AU) distant. Voyager 2's current relative velocity to the Sun is 15.436 km/s (55,570 km/h; 34,530 mph). This calculates as 3.254 AU per year, about 10% slower than Voyager 1. At this velocity, 81,438 years would pass before reaching the nearest star, HP Mini 110-3109sl laptop keyboard

 Proxima Centauri, were the spacecraft traveling in the direction of that star. Voyager 2 will need about 19,390 years at its current velocity to travel a complete light year.)

On November 7, 2012, Voyager 2 reached 100 AU from the sun, making it the third human made object to reach 100 AU. Voyager 1 was 122 AU from the Sun, andPioneer 10 is presumed to be at 107 AU.  HP Mini 210-2070sb laptop keyboard

While Pioneer has ceased communications, both of the Voyager spacecraft are performing well and are still communicating.

Voyager 2 is not headed toward any particular star, although in roughly 40,000 years it should pass 1.7 light-years (9.7 trillion miles) from the star Ross 248. Lenovo 0A62075 laptop keyboard

 And if undisturbed for 296,000 years, Voyager 2 should pass by the star Sirius at a distance of 1.32 parsecs (4.3 ly, 25 trillion miles). Voyager 2 is expected to keep transmitting weak radio messages until at least 2025, over 48 years after it was launched. LENOVO IdeaPad S10 20015 laptop keyboard, Lenovo 3000 Y500 laptop keyboard,HP Pavilion dv6-3023sy laptop keyboard

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