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82-559: Like zodiacal light , gegenschein is sunlight scattered by interplanetary dust . Most of this dust orbits the Sun near the ecliptic plane, with a possible concentration of particles centered at the L 2 point of the Earth–Sun system. Gegenschein is distinguished from zodiacal light by its high angle of reflection of the incident sunlight on the dust particles. It forms a slightly brighter elliptical spot of 8–10° across  directly opposite

164-825: A career in music. He was able to submit it only because of the minimal amount of research on the topic undertaken during the intervening years. May described the subject as being one that became "trendy" again in the 2000s. Other planets, like Venus or Mercury, have shown to have rings of interplanetary dust in their orbital spaces. Solar System   → Local Interstellar Cloud   → Local Bubble   → Gould Belt   → Orion Arm   → Milky Way   → Milky Way subgroup   → Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster   → Local Hole   → Observable universe   → Universe Each arrow ( → ) may be read as "within" or "part of". Pioneer 10 Pioneer 10 (originally designated Pioneer F )

246-452: A clear and moonless night sky. A related phenomenon is gegenschein (or counterglow ), sunlight backscattered from the interplanetary dust, which appears directly opposite to the Sun as a faint but slightly brighter oval glow. Zodiacal light contributes to the natural light of the sky, though since zodiacal light is very faint, it is often outshined and rendered invisible by moonlight or light pollution . The interplanetary dust in

328-402: A command distribution unit, a very limited form of a processor, to direct operations on the spacecraft. This system requires that mission operators prepare commands long in advance of transmitting them to the probe. A data storage unit is included to record up to 6,144  bytes of information gathered by the instruments. The digital telemetry unit is used to prepare the collected data in one of

410-514: A constant spin-rate of 4.8 rpm , pair two controlled the forward thrust, and pair three controlled the attitude. The attitude pair were used in conical scanning maneuvers to track Earth in its orbit. Orientation information was also provided by a star sensor able to reference Canopus , and two Sun sensors . Pioneer 10 uses four SNAP-19 radioisotope thermoelectric generators (RTGs). They are positioned on two three-rod trusses, each 3 meters (9.8 ft) in length and 120 degrees apart. This

492-472: A deficiency of particles below a micrometer (μm) in the belt, as compared to the vicinity of the Earth. The density of dust particles between 10 and 100 μm did not vary significantly during the trip from the Earth to the outer edge of the belt. Only for particles with a diameter of 100 μm to 1.0 mm did the density show an increase, by a factor of three in the region of the belt. No fragments larger than

574-525: A documentary film by George Van Valkenburg titled Jupiter Odyssey . It received numerous international awards, and is visible on Van Valkenburg's YouTube channel. In February 1970, Ames awarded a combined US$ 380 million contract to TRW Inc. for building both of the Pioneer ;10 and 11 vehicles, bypassing the usual bidding process to save time. B. J. O'Brien and Herb Lassen led the TRW team that assembled

656-562: A few weeks every 13 months. Launch during other time intervals would have been more costly in terms of propellant requirements. Approved by NASA in February 1969, the twin spacecraft were designated Pioneer F and Pioneer G before launch; later, they were named Pioneer 10 and Pioneer 11 respectively. They formed part of the Pioneer program , a series of United States uncrewed space missions launched between 1958 and 1978. This model

738-513: A hole in the large dish-shaped antenna to detect particles of the solar wind originating from the Sun. Detects cosmic rays in the Solar System. Collects data on the composition of the cosmic ray particles and their energy ranges. Surveys the intensities, energy spectra, and angular distributions of electrons and protons along the spacecraft's path through the radiation belts of Jupiter. Includes an unfocused Cerenkov counter that detects

820-428: A millimeter were observed in the belt, indicating these are likely rare; certainly much less common than anticipated. As the spacecraft did not collide with any particles of substantial size, it passed safely through the belt, emerging on the other side about February 15, 1973. On November 6, 1973, the Pioneer 10 spacecraft was at a distance of 25 million km (16 million mi) from Jupiter. Testing of

902-435: Is 10,000 times stronger than the maximum radiation around the Earth. Pioneer 10 passed through the inner radiation belts within 20  R J , receiving an integrated dose of 200,000 rads from electrons and 56,000 rads from protons (in comparison, a whole body dose of 500 rads is fatal to humans). The level of radiation at Jupiter was ten times more powerful than Pioneer's designers had predicted, leading to fears that

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984-531: Is a NASA space probe launched in 1972 that completed the first mission to the planet Jupiter . Pioneer 10 became the first of five planetary probes and 11 artificial objects to achieve the escape velocity needed to leave the Solar System . This space exploration project was conducted by the NASA Ames Research Center in California. The space probe was manufactured by TRW Inc. Pioneer 10

1066-457: Is a faint glow of diffuse sunlight scattered by interplanetary dust . Brighter around the Sun , it appears in a particularly dark night sky to extend from the Sun's direction in a roughly triangular shape along the zodiac , and appears with less intensity and visibility along the whole ecliptic as the zodiacal band . Zodiacal light spans the entire sky and contributes to the natural light of

1148-407: Is almost undetectable except when viewed at a small angle with the Sun. Thus it is possible to see more of the width at small angles toward the Sun, and it appears wider near the horizon, closer to the Sun under the horizon. The source of the dust has been long debated. Until recently, it was thought that the dust originated from the tails of active comets and from collisions between asteroids in

1230-467: The Juno spacecraft shows that the distribution of the dust extends from Earth's orbit to the 4:1 orbital resonance with Jupiter at 2.06 AU , and suggests that the dust is from Mars. However, no other dedicated dust instrumentation on Pioneer 10 , Pioneer 11 , Galileo , Ulysses , and Cassini found an indication that Mars is a significant source of dust besides comets and asteroids. In

1312-609: The National Aeronautics and Space Administration from Space Launch Complex 36A in Florida, aboard an Atlas-Centaur . The third stage of the expendable vehicle consisted of a solid fuel Star-37E stage (TE-M-364-4) developed specifically for the Pioneer missions. This stage provided about 15,000 pounds (6,800 kg) of thrust and spun up the spacecraft. The spacecraft had an initial spin rate of 30 rpm. Twenty minutes following

1394-502: The Solar System forms a thick, pancake-shaped cloud called the zodiacal cloud which straddles the ecliptic plane. The particle sizes range from 10 to 300 micrometres , implying masses from one nanogram to tens of micrograms . The Pioneer 10 and Helios spacecraft observations in the 1970s revealed zodiacal light to be scattered by the interplanetary dust cloud in the Solar System. Analysis of images of impact debris from

1476-403: The asteroid belt . Many of our meteor showers have no known active comet parent bodies. Over 85 percent of the dust is attributed to occasional fragmentations of Jupiter-family comets that are nearly dormant . Jupiter-family comets have orbital periods of less than 20 years and are considered dormant when not actively outgassing, but may do so in the future. The first fully dynamical model of

1558-424: The solar wind from 451 km/s (280 mi/s) to 225 km/s (140 mi/s). The magnetopause was passed through a day later. The spacecraft instruments confirmed that the magnetic field of Jupiter was inverted compared to that of Earth. By the 29th, the orbits of all of the outermost moons had been passed, and the spacecraft was operating flawlessly. Red and blue pictures of Jupiter were being generated by

1640-595: The German explorer Alexander von Humboldt during his South American journey from 1799 to 1803. It was Humboldt who first used the German term Gegenschein . However, research conducted in 2021 by Texas State University astronomer and professor Donald Olson discovered that the Danish astronomer Theodor Brorsen was actually the first person to observe and describe one in 1854, although Brorsen had thought that Pézenas had observed it first. Olson believes what Pézenas actually observed

1722-556: The NASA Jet Propulsion Laboratory conceived of a mission, known as the Planetary Grand Tour , that would exploit a rare alignment of the outer planets of the Solar System. This mission would ultimately be accomplished in the late 1970s by the two Voyager probes, but in order to prepare for it, NASA decided in 1964 to experiment with launching a pair of probes to the outer Solar System . An advocacy group named

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1804-460: The Outer Space Panel and chaired by American space scientist James A. Van Allen , worked out the scientific rationale for exploring the outer planets. NASA Goddard Spaceflight Center put together a proposal for a pair of "Galactic Jupiter Probes" that would pass through the asteroid belt and visit Jupiter. These were to be launched in 1972 and 1973 during favorable windows that occurred only

1886-447: The Pioneer program would later receive an Emmy award for this presentation to the media. The motion of the spacecraft produced geometric distortions that later had to be corrected by computer processing. During the encounter, a total of more than 500 images were transmitted. The trajectory of the spacecraft took it along the magnetic equator of Jupiter, where the ion radiation was concentrated. Peak flux for this electron radiation

1968-511: The SNAP-19 was to provide power for two years in space; this was greatly exceeded during the mission. The plutonium-238 has a half-life of 87.74 years, so that after 29 years the radiation being generated by the RTGs was at 80% of its intensity at launch. However, steady deterioration of the thermocouple junctions led to a more rapid decay in electrical power generation, and by 2001 the total power output

2050-512: The Sun as seen from Earth, which would be in full phase . According to Nesvorný and Jenniskens, when the dust grains are as small as about 150 micrometres in size, they will hit the Earth at an average speed of 14.5 km/s, many as slowly as 12 km/s. If so, they pointed out, this comet dust can survive entry in partially molten form, accounting for the unusual attributes of the micrometeorites collected in Antarctica, which do not resemble

2132-600: The Sun within the dimmer band of zodiacal light and zodiac constellation. The intensity of the gegenschein is relatively enhanced because each dust particle is seen at full phase , having a difficult to measure apparent magnitude of +5 to +6, with a very low surface brightness in the +10 to +12 magnitude range. It is commonly stated that the gegenschein was first described by the French Jesuit astronomer and professor Esprit Pézenas  [ fr ] (1692–1776) in 1730. Further observations were supposedly made by

2214-512: The Sun, though the spacecraft was still able to transmit coherent data after this date. After March 31, 1997, Pioneer 10 ' s weak signal continued to be tracked by the Deep Space Network to aid the training of flight controllers in the process of acquiring deep-space radio signals. There was an Advanced Concepts study applying chaos theory to extract coherent data from the fading signal. The last successful reception of telemetry

2296-417: The Sun. Hence a continuous source of new particles is needed to maintain the zodiacal cloud. Cometary dust and dust generated by collisions among the asteroids are believed to be mostly responsible for the maintenance of the dust cloud producing the zodiacal light and the gegenschein . Particles can be reduced in size by collisions or by space weathering. When ground down to sizes less than 10 micrometres,

2378-400: The back of the main dish antenna record penetrating impacts of small meteoroids. Meteoroid-asteroid detector look into space with four non-imaging telescopes to track particles ranging from close by bits of dust to distant large asteroids. Ultraviolet light is sensed to determine the quantities of hydrogen and helium in space and on Jupiter. The imaging experiment relies upon the spin of

2460-475: The bow shock a total of 17 times before it escaped completely. Pioneer 10 crossed the orbit of Saturn in 1976 and the orbit of Uranus in 1979. On June 13, 1983, the craft crossed the orbit of Neptune , and so became the first human-made object to leave the proximity of the major planets of the Solar System. The mission came to an official end on March 31, 1997, when it had reached a distance of 67 AU (10.0 billion km; 6.2 billion mi) from

2542-437: The center and near the south pole, while the north pole appeared brighter. Europa was too far away to obtain a detailed image, although some albedo features were apparent. The trajectory of Pioneer 10 was chosen to take it behind Io, allowing the refractive effect of the moon's atmosphere on the radio transmissions to be measured. This demonstrated that the ionosphere of the moon was about 700 kilometers (430 mi) above

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2624-509: The comets to the inner Solar System. In 2015, new results from the secondary ion dust spectrometer COSIMA on board the ESA/Rosetta orbiter confirmed that the parent bodies of interplanetary dust are most probably Jupiter-family comets such as comet 67P/Churyumov–Gerasimenko . Data from the Juno mission indicate that the dust close to Earth has a local origin in the inner Solar System, best fitting

2706-401: The composition of charged particles, and to measure magnetic fields, plasma, cosmic rays and the zodiacal light . Observation of the spacecraft communications as it passed behind Jupiter would allow measurements of the planetary atmosphere, while tracking data would improve estimates of the mass of Jupiter and its moons. NASA Ames Research Center , rather than Goddard, was selected to manage

2788-453: The environment around Jupiter, the solar wind , cosmic rays , and eventually the far reaches of the Solar System and heliosphere . Radio communications were lost with Pioneer 10 on January 23, 2003, because of the loss of electric power for its radio transmitter , with the probe at a distance of 12  billion   km (80  AU ; 7.5 billion  mi ) from Earth. In the 1960s, American aerospace engineer Gary Flandro of

2870-406: The first spacecraft to traverse the asteroid belt . Photography of Jupiter began on November 6, 1973, at a range of 25 million kilometers (16 million miles ), and about 500 images were transmitted. The closest approach to the planet was on December 3, 1973, at a range of 132,252 kilometers (82,178 mi). During the mission, the on-board instruments were used to study the asteroid belt,

2952-429: The grains are removed from the inner Solar System by solar radiation pressure. The dust is then replenished by the infall from comets. Zodiacal dust around nearby stars is called exozodiacal dust ; it is a potentially important source of noise in attempts to directly image extrasolar planets . It has been pointed out that this exozodiacal dust, or hot debris disks, can be an indicator of planets, as planets tend to scatter

3034-469: The imaging photopolarimeter as the rotation of the spacecraft carried the instrument's field of view past the planet. These red and blue colors were combined to produce a synthetic green image, allowing a three-color combination to produce the rendered image. On November 26, a total of twelve such images were received back on Earth. By December 2, the image quality exceeded the best images made from Earth. These were being displayed in real-time back on Earth, and

3116-404: The imaging system began, and the data were successfully received back at the Deep Space Network. A series of 16,000 commands were then uploaded to the spacecraft to control the flyby operations during the next sixty days. The orbit of the outer moon Sinope was crossed on November 8. The bow shock of Jupiter's magnetosphere was reached on November 16, as indicated by a drop in the velocity of

3198-515: The journey, the spacecraft made three course corrections. The on-board instruments underwent checkouts, with the photometers examining Jupiter and the Zodiacal light , and experiment packages being used to measure cosmic rays, magnetic fields and the solar wind. The only anomaly during this interval was the failure of the Canopus sensor, which instead required the spacecraft to maintain its orientation using

3280-399: The larger meteorites known to originate from asteroids . In recent years, observations by a variety of spacecraft have shown significant structure in the zodiacal light including dust bands associated with debris from particular asteroid families and several cometary trails. According to Alexander von Humboldt 's Kosmos , Mesoamericans were aware of the zodiacal light before 1500. It

3362-492: The last time the antenna would be correctly aligned with Earth. No response was received from Pioneer 10 . NASA decided that the RTG units had probably fallen below the power threshold needed to operate the transmitter. Hence, no further attempts at contact were made. On July 18, 2023, Voyager 2 overtook Pioneer 10 , making Pioneer 10 the third farthest spacecraft from the Sun after Voyager 1 and Voyager 2 . As of June 2024,

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3444-527: The late K-type star HIP 117795 . This is the closest stellar flyby in the next few million years of all the Pioneer , Voyager , and New Horizons spacecraft, which are leaving the Solar System. A backup unit, Pioneer H , is currently on display in the "Milestones of Flight" gallery at the National Air and Space Museum in Washington, D.C. Many elements of the mission proved to be critical in

3526-408: The launch, the vehicle's three booms were extended, which slowed the rotation rate to 4.8 rpm. This rate was maintained throughout the voyage. The launch vehicle accelerated the probe for a net interval of 17 minutes, reaching a velocity of 51,682 km/h (32,114 mph). After the high-gain antenna was contacted, several of the instruments were activated for testing while the spacecraft

3608-416: The light emitted in a particular direction as particles passed through it recording electrons of energy, 0.5 to 12 MeV , an electron scatter detector for electrons of energy, 100 to 400 keV, and a minimum ionizing detector consisting of a solid-state diode that measure minimum ionizing particles (<3 MeV) and protons in the range of 50 to 350 MeV. Twelve panels of pressurized cell detectors mounted on

3690-464: The material is located near the plane of the Solar System, the zodiacal light is seen along the ecliptic . The amount of material needed to produce the observed zodiacal light is quite small. If it were in the form of 1 mm particles, each with the same albedo (reflecting power) as the Moon , each particle would be 8 km from its neighbors. The gegenschein may be caused by particles directly opposite

3772-426: The mid-latitudes, the zodiacal light is best observed in the western sky in the spring after the evening twilight has completely disappeared, or in the eastern sky in the autumn just before the morning twilight appears. The zodiacal light appears as a column, brighter at the horizon and tilted at the angle of the ecliptic. The light scattered from extremely small dust particles is strongly forward scattering , although

3854-441: The planet Mars as a source. Zodiacal light is produced by sunlight reflecting off dust particles in the Solar System known as cosmic dust . Consequently, its spectrum is the same as the solar spectrum. The material producing the zodiacal light is located in a lens-shaped volume of space centered on the sun and extending well out beyond the orbit of Earth. This material is known as the interplanetary dust cloud . Since most of

3936-412: The planet, which confirmed the idea that the planet radiated more heat than it received from the Sun. Crescent images of the planet were then returned as Pioneer 10 moved away from the planet. As the spacecraft headed outward, it again passed the bow shock of Jupiter's magnetosphere. As this front is constantly shifting in space because of dynamic interaction with the solar wind, the vehicle crossed

4018-486: The planning of the Voyager program. Because it was strongly advocated by Carl Sagan , Pioneer 10 and Pioneer 11 carry a 152 by 229 mm (6.0 by 9.0 in) gold-anodized aluminum plaque in case either spacecraft is ever found by intelligent life-forms from another planetary system. The plaques feature the nude figures of a human male and female along with several symbols that are designed to provide information about

4100-413: The probe and eight of the eleven scientific instruments. The equipment compartment lay within an aluminum honeycomb structure to provide protection from meteoroids . A layer of insulation, consisting of aluminized mylar and kapton blankets, provides passive thermal control. Heat was generated by the dissipation of 70 to 120 watts (W) from the electrical components inside the compartment. The heat range

4182-569: The probe closely approaching Jupiter to provide data on the effect the environmental radiation surrounding Jupiter would have on the spacecraft instruments. More than 150 scientific experiments were proposed for the missions. The experiments to be carried on the spacecraft were selected in a series of planning sessions during the 1960s, then were finalized by early 1970. These would be to perform imaging and polarimetry of Jupiter and several of its satellites, make infrared and ultraviolet observations of Jupiter, detect asteroids and meteoroids, determine

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4264-505: The probe is estimated to be 137.3  AU (20.5  billion   km ; 12.8 billion  mi ) from Earth and 136.3  AU (20.4  billion   km ; 12.7 billion  mi ) from the Sun. Sunlight takes 18.9 hours to reach Pioneer 10 . The brightness of the Sun from the spacecraft is magnitude −16.0. Pioneer 10 is currently travelling in the direction of the constellation Taurus . If left undisturbed, Pioneer 10 and its sister craft Pioneer 11 will join

4346-462: The probe would not survive. Starting on December 3, the radiation around Jupiter caused false commands to be generated. Most of these were corrected by contingency commands, but an image of Io and a few close-ups of Jupiter were lost. Similar false commands would be generated on the way out from the planet. Nonetheless, Pioneer 10 did succeed in obtaining images of the moons Ganymede and Europa . The image of Ganymede showed low albedo features in

4428-456: The project as part of the Pioneer program. The Ames Research Center, under the direction of Charles F. Hall, was chosen because of its previous experience with spin-stabilized spacecraft. The requirements called for a small, lightweight spacecraft which was magnetically clean and which could perform an interplanetary mission. It was to use spacecraft modules that had already been proven in the Pioneer 6 through 9 missions. Ames commissioned

4510-399: The radius of the planet, which was thought to be the closest it could approach and still survive the radiation. The trajectory chosen would give the spacecraft a good view of the sunlit side. The Pioneer 10 bus measures 36 centimeters (14 in) deep and with six 76-centimeter (30 in) long panels forming the hexagonal structure. The bus houses propellant to control the orientation of

4592-437: The receiving equipment on Earth. The data transmission rate at launch was 256 bit/s, with the rate degrading by about 1.27 millibit/s for each day during the mission. Much of the computation for the mission is performed on Earth and transmitted to the spacecraft, where it was able to retain in memory up to five commands of the 222 possible entries by ground controllers. The spacecraft includes two command decoders and

4674-403: The sky. Brorsen published the first thorough investigations of the gegenschein in 1854. T. W. Backhouse discovered it independently in 1876, as did Edward Emerson Barnard in 1882. In modern times, the gegenschein is not visible in most inhabited regions of the world due to light pollution . Zodiacal light The zodiacal light (also called false dawn when seen before sunrise )

4756-428: The spacecraft to sweep a small telescope across the planet in narrow strips only 0.03 degrees wide, looking at the planet in red and blue light. These strips were then processed to build up a visual image of the planet. Provides information on cloud temperature and the output of heat from Jupiter. Pioneer 10 was launched on March 3, 1972, at 01:49:00 UTC (8:49 p.m. Eastern Standard Time on March 2) by

4838-549: The spacecraft. Design and construction of the spacecraft required an estimated 25 million man-hours. An engineer from TRW quipped, "This spacecraft is guaranteed for two years of interplanetary flight. If any component fails within that warranty period, just return the spacecraft to our shop and we will repair it free of charge." To meet the schedule, the first launch would need to take place between February 29 and March 17 so that it could arrive at Jupiter in November 1974. This

4920-423: The surface of the day side, and the density ranged from 60,000 electrons per cubic centimeter on the dayside to 9,000 electrons per cubic centimeter on the night face. An unexpected discovery was that Io was orbiting within a cloud of hydrogen that extended for about 805,000 kilometers (500,000 mi), with a width and height of 402,000 kilometers (250,000 mi). A smaller, 110,000-kilometer (68,000 mi) cloud

5002-441: The temperature structure of the outer atmosphere to be measured, showing a temperature inversion between the altitudes with 10 and 100  mbar pressures. Temperatures at the 10-mbar level ranged from −133 to −113  °C (140 to 160  K ; −207 to −171  °F ), while temperatures at the 100 mbar level were −183 to −163 °C (90.1 to 110.1 K; −297.4 to −261.4 °F). The spacecraft generated an infrared map of

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5084-493: The thirteen possible formats before transmitting it back to Earth. This instrument measures the fine structure of the interplanetary magnetic field, mapped the Jovian magnetic field, and provided magnetic field measurements to evaluate solar wind interaction with Jupiter. The magnetometer consists of a helium-filled cell mounted on a 6.6 m boom to partly isolate the instrument from the spacecraft's magnetic field. Peers through

5166-426: The timing of the five daily prayers , calling it the "false dawn" ( الفجر الكاذب al-fajr al-kādhib ). Muslim oral tradition preserves numerous sayings, or hadith , in which Muhammad describes the difference between the light of false dawn, appearing in the sky long after sunset, and the light of the first band of horizontal light at sunrise, the "true dawn" ( الفجر الصادق al-fajr al-sādiq ). According to

5248-465: The two Sun sensors. While passing through interplanetary medium , Pioneer 10 became the first mission to detect interplanetary atoms of helium. It also observed high-energy ions of aluminum and sodium in the solar wind . The spacecraft recorded important heliophysics data in early August 1972 by registering a solar shock wave when it was at a distance of 2.2 AU (330 million km; 200 million mi). On July 15, 1972, Pioneer 10

5330-578: The two Voyager spacecraft and the New Horizons spacecraft in leaving the Solar System to wander the interstellar medium . The Pioneer 10 trajectory is expected to take it in the general direction of the star Aldebaran , currently located at a distance of about 68  light years . If Aldebaran had zero relative velocity , it would require more than two million years for the spacecraft to reach it. Well before that, in about 90,000 years, Pioneer 10 will pass about 0.23 parsecs (0.75 light-years ) from

5412-485: The vast majority of Muslim scholars, astronomical dawn is considered the true dawn. Practitioners of Islam use Muhammad's descriptions of zodiacal light to avoid errors in determining the timing of fasting and daily prayers. In 2007, Brian May , lead guitarist with the band Queen , completed his thesis , A Survey of Radial Velocities in the Zodiacal Dust Cloud , thirty-six years after abandoning it to pursue

5494-452: The zodiacal cloud demonstrated that only if the dust was released in orbits that approach Jupiter, is it stirred up enough to explain the thickness of the zodiacal dust cloud. The dust in meteoroid streams is much larger, 300 to 10,000 micrometres in diameter, and falls apart into smaller zodiacal dust grains over time. The Poynting–Robertson effect forces the dust into more circular (but still elongated) orbits, while spiralling slowly into

5576-408: The zodiacal light actually extends all the way around the sky, hence it is brightest when observing at a small angle with the Sun. This is why it is most clearly visible near sunrise or sunset when the Sun is blocked, but the dust particles nearest the line of sight to the Sun are not. The dust band that causes the zodiacal light is uniform across the whole ecliptic. The dust further from the ecliptic

5658-439: Was 65 W. As a result, later in the mission only selected instruments could be operated at any one time. The space probe includes a redundant system of transceivers , one attached to the narrow-beam, high-gain antenna , the other to an omni-antenna and medium-gain antenna. The parabolic dish for the high-gain antenna is 2.74 meters (9.0 ft) in diameter and made from an aluminum honeycomb sandwich material. The spacecraft

5740-407: Was an auroral event, as he described the phenomenon as having a red glow; Olson found many other reports of auroral activity from around Europe and Asia on the same date Pézenas made his observation. Humboldt's report instead described glowing triangular patches on both the western and eastern horizons shortly after sunset, while true gegenschein is most visible near local midnight when it is highest in

5822-533: Was assembled around a hexagonal bus with a 2.74-meter (9 ft 0 in) diameter parabolic dish high-gain antenna , and the spacecraft was spin stabilized around the axis of the antenna. Its electric power was supplied by four radioisotope thermoelectric generators that provided a combined 155 watts at launch. It was launched on March 3, 1972, at 01:49:00 UTC (March 2 local time), by an Atlas-Centaur rocket from Cape Canaveral , Florida . Between July 15, 1972, and February 15, 1973, it became

5904-403: Was believed to have been detected near Europa. It was not until after Pioneer 10 had cleared the asteroid belt that NASA selected a trajectory towards Jupiter which included a slingshot effect to send the spacecraft out of the Solar System. Pioneer 10 was the first spacecraft to attempt such a maneuver, a model for future missions. Such an extended mission was not in the initial proposal, but

5986-433: Was expected to be a safe distance from the sensitive scientific experiments carried on board. Combined, the RTGs provided 155 W at launch, and decayed to 140 W in transit to Jupiter. The spacecraft required 100 W to power all systems. The generators are powered by the radioisotope fuel plutonium-238 , which is housed in a multi-layer capsule protected by a graphite heat shield. The pre-launch requirement for

6068-535: Was later revised to an arrival date of December 1973 in order to avoid conflicts with other missions over the use of the Deep Space Network for communications, and to miss the period when Earth and Jupiter would be at opposite sides of the Sun. The encounter trajectory for Pioneer 10 was selected to maximize the information returned about the radiation environment around Jupiter, even if this caused damage to some systems. It would come within about three times

6150-476: Was maintained within the operating limits of the equipment by means of louvers located below the mounting platform. The spacecraft had a launch mass of about 260 kilograms (570 lb). At launch, the spacecraft carried 36 kilograms (79 lb) of liquid hydrazine monopropellant in a 42-centimeter (17 in) diameter spherical tank. Orientation of the spacecraft is maintained with six 4.5 N , hydrazine thrusters mounted in three pairs. Pair one maintained

6232-465: Was moving through the Earth's radiation belts. Ninety minutes after launch, the spacecraft reached interplanetary space. Pioneer 10 passed by the Moon in 11 hours and became the fastest human-made object at that time. Two days after launch, the scientific instruments were turned on, beginning with the cosmic ray telescope. After ten days, all of the instruments were active. During the first seven months of

6314-457: Was perhaps first reported in print by Joshua Childrey in 1661. The phenomenon was investigated by the astronomer Giovanni Domenico Cassini in 1683. According to some sources, he explained it by dust particles around the Sun. Other sources state that it was first explained this way by Nicolas Fatio de Duillier , in 1684, whom Cassini advised to study the zodiacal light. The Islamic prophet Muhammad described zodiacal light in reference to

6396-490: Was planned for prior to launch. At the closest approach, the velocity of the spacecraft reached 132,000 km/h (82,000 mph; 37,000 m/s), and it came within 132,252 kilometers (82,178 mi) of the outer atmosphere of Jupiter. Close-up images of the Great Red Spot and the terminator were obtained. Communication with the spacecraft then ceased as it passed behind the planet. The radio occultation data allowed

6478-421: Was received from Pioneer 10 on April 27, 2002; subsequent signals were barely strong enough to detect and provided no usable data. The final, very weak signal from Pioneer 10 was received on January 23, 2003, when it was 12 billion km (80 AU; 7.5 billion mi) from Earth. Further attempts to contact the spacecraft were unsuccessful. A final attempt was made on the evening of March 4, 2006,

6560-508: Was spun about an axis that is parallel to the axis of this antenna so that it could remain oriented toward the Earth. Each transceiver is an 8 W one and transmits data across the S-band using 2110 MHz for the uplink from Earth and 2292 MHz for the downlink to Earth with the Deep Space Network tracking the signal. Data to be transmitted is passed through a convolutional encoder so that most communication errors could be corrected by

6642-406: Was the first in the series to be designed for exploring the outer Solar System. Based on proposals issued throughout the 1960s, the early mission objectives were to explore the interplanetary medium past the orbit of Mars, study the asteroid belt and assess the possible hazard to spacecraft traveling through the belt, and explore Jupiter and its environment. Later development-stage objectives included

6724-432: Was the first spacecraft to enter the asteroid belt, located between the orbits of Mars and Jupiter. The project planners expected a safe passage through the belt, and the closest the trajectory would take the spacecraft to any of the known asteroids was 8.8 million kilometers (5.5 million miles). One of the nearest approaches was to the asteroid 307 Nike on December 2, 1972. The on-board experiments demonstrated

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