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137-427: Since signals between the spacecraft and Earth are limited to the speed of light, there is a delay between the time an event happens on the spacecraft (such as the transmission of data taken from an instrument reading) and the time that a signal reporting the event reaches Earth. Similarly, there is a delay between when instructions are sent from Earth and when the spacecraft receives the instructions. The length of delay

274-423: A gravity assist that increased New Horizons ' speed; the flyby also enabled a general test of New Horizons ' scientific capabilities, returning data about the planet's atmosphere , moons , and magnetosphere . Most of the post-Jupiter voyage was spent in hibernation mode to preserve onboard systems, except for brief annual checkouts. On December 6, 2014, New Horizons was brought back online for

411-423: A latency of about 4.5 hours (one-way). The 70 m (230 ft) NASA Deep Space Network (DSN) dishes are used to relay commands once the spacecraft is beyond Jupiter. The spacecraft uses dual modular redundancy transmitters and receivers, and either right- or left-hand circular polarization . The downlink signal is amplified by dual redundant 12-watt traveling-wave tube amplifiers (TWTAs) mounted on

548-493: A change of plans such that the entire probe was rotated to make photos at Uranus and Neptune, similar to how New Horizons rotated. New Horizons carries seven instruments: three optical instruments, two plasma instruments, a dust sensor and a radio science receiver/radiometer. The instruments are to be used to investigate the global geology, surface composition, surface temperature, atmospheric pressure, atmospheric temperature and escape rate of Pluto and its moons. The rated power

685-521: A collection of images of New Horizons project personnel on another CD, a piece of Scaled Composites 's SpaceShipOne , a "Not Yet Explored" USPS stamp, and two copies of the Flag of the United States . About 30 grams (1 oz) of Clyde Tombaugh's ashes are aboard the spacecraft, to commemorate his discovery of Pluto in 1930. A Florida state quarter coin, whose design commemorates human exploration,

822-468: A combined mass 7–25 times the Earth. This mixing process could have arisen during formation, while the planet accreted solids and gases from the surrounding nebula. Alternatively, it could have been caused by an impact from a planet of about ten Earth masses a few million years after Jupiter's formation, which would have disrupted an originally compact Jovian core. Outside the layer of metallic hydrogen lies

959-456: A composite light shield and mount with titanium and fiberglass for thermal isolation. Overall mass is 8.6 kg (19 lb), with the optical tube assembly (OTA) weighing about 5.6 kg (12 lb), for one of the largest silicon-carbide telescopes flown at the time (now surpassed by Herschel ). For viewing on public web sites the 12-bit per pixel LORRI images are converted to 8-bit per pixel JPEG images. These public images do not contain

1096-410: A connection with the spacecraft: the first letters of their names (N and H) are the initials of New Horizons . The moons' discoverers chose these names for this reason, plus Nix and Hydra's relationship to the mythological Pluto . In addition to the science equipment, there are nine cultural artifacts traveling with the spacecraft. These include a collection of 434,738 names stored on a compact disc,

1233-572: A higher orbit, disrupting the orbits of Uranus and Neptune, depleting the Kuiper belt, and triggering the Late Heavy Bombardment . Based on Jupiter's composition, researchers have made the case for an initial formation outside the molecular nitrogen (N 2 ) snow line, which is estimated at 20–30 AU (3.0–4.5 billion km; 1.9–2.8 billion mi) from the Sun, and possibly even outside

1370-471: A large one in the centre and eight others around it, while its southern counterpart also consists of a centre vortex but is surrounded by five large storms and a single smaller one for a total of 7 storms. In 2000, an atmospheric feature formed in the southern hemisphere that is similar in appearance to the Great Red Spot, but smaller. This was created when smaller, white oval-shaped storms merged to form

1507-533: A mass of 60.4   M J . Theoretical models indicate that if Jupiter had over 40% more mass, the interior would be so compressed that its volume would decrease despite the increasing amount of matter. For smaller changes in its mass, the radius would not change appreciably. As a result, Jupiter is thought to have about as large a diameter as a planet of its composition and evolutionary history can achieve. The process of further shrinkage with increasing mass would continue until appreciable stellar ignition

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1644-408: A period of about 121 days, moving backward through an angle of 9.9° before returning to prograde movement. Because the orbit of Jupiter is outside that of Earth, the phase angle of Jupiter as viewed from Earth is always less than 11.5°; thus, Jupiter always appears nearly fully illuminated when viewed through Earth-based telescopes. It was during spacecraft missions to Jupiter that crescent views of

1781-460: A radius of 60,000 km (37,000 mi) (11,000 km (6,800 mi) below the cloud tops) and merge again at 50,000 km (31,000 mi) (22,000 km (14,000 mi) beneath the clouds). Rainfalls of diamonds have been suggested to occur, as well as on Saturn and the ice giants Uranus and Neptune. The temperature and pressure inside Jupiter increase steadily inward as the heat of planetary formation can only escape by convection. At

1918-717: A series of proposed Pluto missions leading up to New Horizons . Stamatios "Tom" Krimigis , head of the Applied Physics Laboratory 's space division, one of many entrants in the New Frontiers Program competition, formed the New Horizons team with Alan Stern in December 2000. Appointed as the project's principal investigator , Stern was described by Krimigis as "the personification of the Pluto mission". New Horizons

2055-580: A single feature—these three smaller white ovals were formed in 1939–1940. The merged feature was named Oval BA . It has since increased in intensity and changed from white to red, earning it the nickname "Little Red Spot". In April 2017, a "Great Cold Spot" was discovered in Jupiter's thermosphere at its north pole . This feature is 24,000 km (15,000 mi) across, 12,000 km (7,500 mi) wide, and 200 °C (360 °F) cooler than surrounding material. While this spot changes form and intensity over

2192-540: A slight but noticeable bulge around the equator. The outer atmosphere is divided into a series of latitudinal bands, with turbulence and storms along their interacting boundaries; the most obvious result of this is the Great Red Spot , a giant storm that has been recorded since 1831. Jupiter's magnetic field is the strongest and second-largest contiguous structure in the Solar System, generated by eddy currents within

2329-515: A slower trajectory directly to Pluto, delaying its encounter by five to six years. Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System . It is a gas giant with a mass more than 2.5 times that of all the other planets in the Solar System combined and slightly less than one-thousandth the mass of the Sun. Its diameter is eleven times that of Earth , and

2466-538: A spacecraft could be instructed to go into safe mode to protect it during a coronal mass ejection (CME) from the Sun . Spacecraft event times stored in relation to instrument data from spacecraft events (e.g. images) are generally presented in ISO 8601 using one of the following formats: However, the trailing Z (which indicates that the time is given in UTC ) is often assumed/omitted. New Horizons New Horizons

2603-437: A surface depth where the atmospheric pressure level is 1  bar (0.10  MPa ), the temperature is around 165 K (−108 °C; −163 °F). The region where supercritical hydrogen changes gradually from a molecular fluid to a metallic fluid spans pressure ranges of 50–400 GPa with temperatures of 5,000–8,400 K (4,730–8,130 °C; 8,540–14,660 °F), respectively. The temperature of Jupiter's diluted core

2740-457: A tenth that of the Sun. Jupiter orbits the Sun at a distance of 5.20  AU (778.5  Gm ), with an orbital period of 11.86  years . It is the third brightest natural object in the Earth's night sky , after the Moon and Venus , and has been observed since prehistoric times . Its name derives from that of Jupiter , the chief deity of ancient Roman religion . Jupiter was the first of

2877-403: A transparent interior atmosphere of hydrogen. At this depth, the pressure and temperature are above molecular hydrogen's critical pressure of 1.3 MPa and critical temperature of 33  K (−240.2  °C ; −400.3  °F ). In this state, there are no distinct liquid and gas phases—hydrogen is said to be in a supercritical fluid state. The hydrogen and helium gas extending downward from

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3014-477: A triangle, almost 0.76 m (2.5 ft) thick. (The Pioneers have hexagonal bodies, whereas the Voyagers , Galileo , and Cassini–Huygens have decagonal , hollow bodies.) A 7075 aluminium alloy tube forms the main structural column, between the launch vehicle adapter ring at the "rear", and the 2.1 m (6 ft 11 in) radio dish antenna affixed to the "front" flat side. The titanium fuel tank

3151-515: A visible-light CCD imager with broadband and color channels; and LEISA (Linear Etalon Imaging Spectral Array), a near- infrared imaging spectrometer. LEISA is derived from a similar instrument on the Earth Observing-1 spacecraft. Ralph was named after Alice's husband on The Honeymooners , and was designed after Alice. On June 23, 2017, NASA announced that it has renamed the LEISA instrument to

3288-452: Is 21 watts , though not all instruments operate simultaneously. In addition, New Horizons has an Ultrastable Oscillator subsystem, which may be used to study and test the Pioneer anomaly towards the end of the spacecraft's life. The Long-Range Reconnaissance Imager (LORRI) is a long-focal-length imager designed for high resolution and responsivity at visible wavelengths. The instrument

3425-401: Is 80% of the Sun's, similar to Saturn 's composition. The ongoing contraction of Jupiter's interior generates more heat than the planet receives from the Sun. Its internal structure is believed to consist of an outer mantle of fluid metallic hydrogen and a diffuse inner core of denser material. Because of its rapid rate of rotation, one turn in ten hours, Jupiter is an oblate spheroid ; it has

3562-405: Is a gas giant , meaning its chemical composition is primarily hydrogen and helium. These materials are classified as gasses in planetary geology, a term that does not denote the state of matter. It is the largest planet in the Solar System, with a diameter of 142,984 km (88,846 mi) at its equator , giving it a volume 1,321 times that of the Earth. Its average density, 1.326 g/cm ,

3699-454: Is about 50 km (31 mi) deep and consists of at least two decks of ammonia clouds: a thin, clearer region on top and a thicker, lower deck. There may be a thin layer of water clouds underlying the ammonia clouds, as suggested by flashes of lightning detected in the atmosphere of Jupiter. These electrical discharges can be up to a thousand times as powerful as lightning on Earth. The water clouds are assumed to generate thunderstorms in

3836-414: Is about ten times larger than Earth ( 11.209  R 🜨 ) and smaller than the Sun ( 0.102 76   R ☉ ). Jupiter's mass is 318 times that of Earth; 2.5 times that of all the other planets in the Solar System combined. It is so massive that its barycentre with the Sun lies above the Sun's surface at 1.068  solar radii from the Sun's centre. Jupiter's radius is about one tenth

3973-453: Is also enclosed in blankets that extend to the body. The heat from the RTG adds warmth to the spacecraft while it is in the outer Solar System. While in the inner Solar System, the spacecraft must prevent overheating, hence electronic activity is limited, power is diverted to shunts with attached radiators, and louvers are opened to radiate excess heat. While the spacecraft is cruising inactively in

4110-674: Is an interplanetary space probe launched as a part of NASA 's New Frontiers program . Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research Institute (SwRI), with a team led by Alan Stern , the spacecraft was launched in 2006 with the primary mission to perform a flyby study of the Pluto system in 2015, and a secondary mission to fly by and study one or more other Kuiper belt objects (KBOs) in

4247-444: Is an oblate spheroid, meaning that the diameter across its equator is longer than the diameter measured between its poles . On Jupiter, the equatorial diameter is 9,276 km (5,764 mi) longer than the polar diameter. Three systems are used as frames of reference for tracking planetary rotation, particularly when graphing the motion of atmospheric features. System I applies to latitudes from 7° N to 7° S; its period

Spacecraft Event Time - Misplaced Pages Continue

4384-581: Is approximately $ 700 million over 15 years (2001–2016). The spacecraft was built primarily by Southwest Research Institute (SwRI) and the Johns Hopkins Applied Physics Laboratory. The mission's principal investigator is Alan Stern of the Southwest Research Institute (formerly NASA Associate Administrator). After separation from the launch vehicle, overall control was taken by Mission Operations Center (MOC) at

4521-716: Is clad in iridium , then encased in a graphite shell. It was developed by the U.S. Department of Energy at the Materials and Fuels Complex, a part of the Idaho National Laboratory . The original RTG design called for 10.9 kg (24 lb) of plutonium, but a unit less powerful than the original design goal was produced because of delays at the United States Department of Energy, including security activities, that delayed plutonium production. The mission parameters and observation sequence had to be modified for

4658-413: Is denser, with a composition of roughly 71% hydrogen, 24% helium, and 5% other elements by mass. The atmospheric proportions of hydrogen and helium are close to the theoretical composition of the primordial solar nebula . Neon in the upper atmosphere consists of 20 parts per million by mass, which is about a tenth as abundant as in the Sun. Jupiter's helium abundance is about 80% that of the Sun due to

4795-450: Is designed to act as shielding , reducing electronics errors caused by radiation from the RTG. Also, the mass distribution required for a spinning spacecraft demands a wider triangle. The interior structure is painted black to equalize temperature by radiative heat transfer. Overall, the spacecraft is thoroughly blanketed to retain heat. Unlike the Pioneers and Voyagers , the radio dish

4932-562: Is equipped with a 1024×1024 pixel by 12-bits-per-pixel monochromatic CCD imager giving a resolution of 5  μrad (~1  arcsec ). The CCD is chilled far below freezing by a passive radiator on the antisolar face of the spacecraft. This temperature differential requires insulation and isolation from the rest of the structure. The 208.3 mm (8.20 in) aperture Ritchey–Chretien mirrors and metering structure are made of silicon carbide to boost stiffness, reduce weight and prevent warping at low temperatures. The optical elements sit in

5069-411: Is estimated to be 20,000 K (19,700 °C; 35,500 °F) with a pressure of around 4,000 GPa. The atmosphere of Jupiter is primarily composed of molecular hydrogen and helium, with a smaller amount of other compounds such as water, methane, hydrogen sulfide, and ammonia. Jupiter's atmosphere extends to a depth of approximately 3,000 km (2,000 mi) below the cloud layers. Jupiter

5206-413: Is in this tube. The RTG attaches with a 4-sided titanium mount resembling a gray pyramid or stepstool. Titanium provides strength and thermal isolation. The rest of the triangle is primarily sandwich panels of thin aluminum face sheet (less than 1 ⁄ 64  in or 0.40 mm) bonded to aluminum honeycomb core. The structure is larger than strictly necessary, with empty space inside. The structure

5343-483: Is included, officially as a trim weight, as is a Maryland state quarter to honor the probe's builders. One of the science packages (a dust counter) is named after Venetia Burney , who, as a child, suggested the name "Pluto" after its discovery. The goal of the mission is to understand the formation of the Plutonian system, the Kuiper belt, and the transformation of the early Solar System. The spacecraft collected data on

5480-670: Is lower than those of the four terrestrial planets . The atmosphere of Jupiter is approximately 76% hydrogen and 24% helium by mass. By volume, the upper atmosphere is about 90% hydrogen and 10% helium, with the lower proportion owing to the individual helium atoms being more massive than the molecules of hydrogen formed in this part of the atmosphere. The atmosphere contains trace amounts of elemental carbon , oxygen , sulfur , and neon , as well as ammonia , water vapour , phosphine , hydrogen sulfide , and hydrocarbons like methane , ethane and benzene . Its outermost layer contains crystals of frozen ammonia. The planet's interior

5617-489: Is nearly circular. This low eccentricity is at odds with exoplanet discoveries, which have revealed Jupiter-sized planets with very high eccentricities. Models suggest this may be due to there being two giant planets in our Solar System, as the presence of a third or more giant planets tends to induce larger eccentricities. The axial tilt of Jupiter is 3.13°, which is relatively small, so its seasons are insignificant compared to those of Earth and Mars. Jupiter's rotation

Spacecraft Event Time - Misplaced Pages Continue

5754-675: Is perpetually covered with clouds of ammonia crystals, which may contain ammonium hydrosulfide as well. The clouds are located in the tropopause layer of the atmosphere, forming bands at different latitudes, known as tropical regions. These are subdivided into lighter-hued zones and darker belts . The interactions of these conflicting circulation patterns cause storms and turbulence . Wind speeds of 100 metres per second (360 km/h; 220 mph) are common in zonal jet streams . The zones have been observed to vary in width, colour and intensity from year to year, but they have remained stable enough for scientists to name them. The cloud layer

5891-475: Is related to the distance between the sending and receiving points. Failure to take this delay into account could result in inaccurate data or mistakes in spacecraft control. Determining the Spacecraft Event Time involves taking the time at Earth and adding or subtracting the signal travel time, depending on whether the signal is being sent to or received from the spacecraft. For events transmitted from

6028-639: Is the Mongoose-V , a 12 MHz radiation-hardened version of the MIPS R3000 CPU . Multiple redundant clocks and timing routines are implemented in hardware and software to help prevent faults and downtime. To conserve heat and mass, spacecraft and instrument electronics are housed together in IEMs (integrated electronics modules). There are two redundant IEMs. Including other functions such as instrument and radio electronics, each IEM contains 9 boards. The software of

6165-414: Is the fastest of all the Solar System's planets, completing a rotation on its axis in slightly less than ten hours; this creates an equatorial bulge easily seen through an amateur telescope. Because Jupiter is not a solid body, its upper atmosphere undergoes differential rotation . The rotation of Jupiter's polar atmosphere is about 5 minutes longer than that of the equatorial atmosphere. The planet

6302-558: Is the lead on the New Horizons navigation team and is responsible for planning trajectory adjustments as the spacecraft speeds toward the outer Solar System . Coincidentally the Naval Observatory Flagstaff Station was where the photographic plates were taken for the discovery of Pluto's moon Charon . The Naval Observatory itself is not far from the Lowell Observatory where Pluto was discovered. New Horizons

6439-530: Is the planet's shortest, at 9h 50 m 30.0s. System II applies at latitudes north and south of these; its period is 9h 55 m 40.6s. System III was defined by radio astronomers and corresponds to the rotation of the planet's magnetosphere; its period is Jupiter's official rotation. Jupiter is usually the fourth brightest object in the sky (after the Sun, the Moon , and Venus ), although at opposition Mars can appear brighter than Jupiter. Depending on Jupiter's position with respect to

6576-448: Is the strongest of any planet in the Solar System, with a dipole moment of 4.170 gauss (0.4170  mT ) that is tilted at an angle of 10.31° to the pole of rotation. The surface magnetic field strength varies from 2 gauss (0.20 mT) up to 20 gauss (2.0 mT). This field is thought to be generated by eddy currents —swirling movements of conducting materials—within the fluid, metallic hydrogen core. At about 75 Jupiter radii from

6713-407: Is to extend operations for New Horizons until the spacecraft exits the Kuiper belt, which is expected to occur between 2028 and 2029. In August 1992, JPL scientist Robert Staehle called Pluto discoverer Clyde Tombaugh , requesting permission to visit his planet. "I told him he was welcome to it," Tombaugh later remembered, "though he's got to go one long, cold trip." The call eventually led to

6850-627: Is used as a pressurant, with an elastomeric diaphragm assisting expulsion. The spacecraft's on-orbit mass including fuel is over 470 kg (1,040 lb) on the Jupiter flyby trajectory, but would have been only 445 kg (981 lb) for the backup direct flight option to Pluto. Significantly, had the backup option been taken, this would have meant less fuel for later Kuiper belt operations. There are 16 thrusters on New Horizons : four 4.4  N (1.0  lbf ) and twelve 0.9 N (0.2 lbf) plumbed into redundant branches. The larger thrusters are used primarily for trajectory corrections, and

6987-754: The Atlas V 's kerosene tank. Further delays related to low cloud ceiling conditions downrange , and high winds and technical difficulties—unrelated to the rocket itself—prevented launch for a further two days. The probe finally lifted off from Pad 41 at Cape Canaveral Air Force Station , Florida , directly south of Space Shuttle Launch Complex 39 , at 19:00 UTC on January 19, 2006. The Centaur second stage ignited at 19:04:43 UTC and burned for 5 minutes 25 seconds. It reignited at 19:32 UTC and burned for 9 minutes 47 seconds. The ATK Star 48 B third stage ignited at 19:42:37 UTC and burned for 1 minute 28 seconds. Combined, these burns successfully sent

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7124-506: The New Horizons spacecraft, a " hydrogen wall " at the outer edges of the Solar System that was first detected in 1992 by the two Voyager spacecraft . The Ralph telescope, 75 mm in aperture, is one of two photographic instruments that make up New Horizons ' Pluto Exploration Remote Sensing Investigation (PERSI), with the other being the Alice instrument. Ralph has two separate channels: MVIC (Multispectral Visible Imaging Camera),

7261-710: The University of Colorado Boulder , led by principal investigator Larry W. Esposito , and supported by the JPL, Lockheed Martin and the University of California . However, the APL, in addition to being supported by Pluto Kuiper Express developers at the Goddard Space Flight Center and Stanford University were at an advantage; they had recently developed NEAR Shoemaker for NASA, which had successfully entered orbit around 433 Eros earlier that year, and would later land on

7398-493: The Voyager program probes, had a rotatable instrumentation platform (a "scan platform") that could take measurements from virtually any angle without losing radio contact with Earth. New Horizons was mechanically simplified to save weight, shorten the schedule, and improve reliability during its 15-year designed lifetime. The Voyager 2 scan platform jammed at Saturn, and the demands of long time exposures at outer planets led to

7535-407: The high-gain antenna , there are two backup low-gain antennas and a medium-gain dish. The high-gain dish has a Cassegrain reflector layout, composite construction, of 2.1-meter (7 ft) diameter providing over 42  dBi of gain and a half-power beam width of about a degree. The prime-focus medium-gain antenna, with a 0.3-meter (1 ft) aperture and 10° half-power beam width, is mounted to

7672-605: The precipitation of these elements as helium-rich droplets, a process that happens deep in the planet's interior. Based on spectroscopy , Saturn is thought to be similar in composition to Jupiter, but the other giant planets Uranus and Neptune have relatively less hydrogen and helium and relatively more of the next most common elements , including oxygen, carbon, nitrogen, and sulfur. These planets are known as ice giants because during their formation, these elements are thought to have been incorporated into them as ice; however, they probably contain very little ice. Jupiter

7809-485: The " Suì Star" ( Suìxīng 歲星 ) and established their cycle of 12 earthly branches based on the approximate number of years it takes Jupiter to rotate around the Sun; the Chinese language still uses its name ( simplified as 歲 ) when referring to years of age. By the 4th century BC, these observations had developed into the Chinese zodiac , and each year became associated with a Tai Sui star and god controlling

7946-593: The "Lisa Hardaway Infrared Mapping Spectrometer" in honor of Lisa Hardaway , the Ralph program manager at Ball Aerospace , who died in January 2017 at age 50. The Venetia Burney Student Dust Counter (VBSDC), built by students at the University of Colorado Boulder, is operating periodically to make dust measurements. It consists of a detector panel, about 460 mm × 300 mm (18 in × 12 in), mounted on

8083-423: The 1660s, Giovanni Cassini used a new telescope to discover spots in Jupiter's atmosphere, observe that the planet appeared oblate, and estimate its rotation period. In 1692, Cassini noticed that the atmosphere undergoes a differential rotation. The Great Red Spot may have been observed as early as 1664 by Robert Hooke and in 1665 by Cassini, although this is disputed. The pharmacist Heinrich Schwabe produced

8220-667: The Applied Physics Laboratory in Howard County, Maryland . The science instruments are operated at Clyde Tombaugh Science Operations Center (T-SOC) in Boulder, Colorado . Navigation is performed at various contractor facilities, whereas the navigational positional data and related celestial reference frames are provided by the Naval Observatory Flagstaff Station through Headquarters NASA and JPL . KinetX

8357-485: The Earth, it can vary in visual magnitude from as bright as −2.94 at opposition down to −1.66 during conjunction with the Sun. The mean apparent magnitude is −2.20 with a standard deviation of 0.33. The angular diameter of Jupiter likewise varies from 50.1 to 30.5 arc seconds . Favourable oppositions occur when Jupiter is passing through the perihelion of its orbit, bringing it closer to Earth. Near opposition, Jupiter will appear to go into retrograde motion for

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8494-563: The Kuiper belt, are speculative. The VBSDC is always turned on measuring the masses of the interplanetary and interstellar dust particles (in the range of nano- and picograms) as they collide with the PVDF panels mounted on the New Horizons spacecraft. The measured data is expected to greatly contribute to the understanding of the dust spectra of the Solar System. The dust spectra can then be compared with those from observations of other stars, giving new clues as to where Earth-like planets can be found in

8631-499: The Pluto encounter, and instrument check-out began. On January 15, 2015, the spacecraft began its approach phase to Pluto. On July 14, 2015, at 11:49  UTC , it flew 12,500 km (7,800 mi) above the surface of Pluto, which at the time was 34 AU from the Sun, making it the first spacecraft to explore the dwarf planet. In August 2016, New Horizons was reported to have traveled at speeds of more than 84,000 km/h (52,000 mph). On October 25, 2016, at 21:48 UTC,

8768-737: The Science Mission Directorate, Ed Weiler , prompted Stern to lobby for the funding of New Horizons in hopes of the mission appearing in the Planetary Science Decadal Survey , a prioritized "wish list," compiled by the United States National Research Council , that reflects the opinions of the scientific community. After an intense campaign to gain support for New Horizons , the Planetary Science Decadal Survey of 2003–2013

8905-448: The Sun is 778 million km ( 5.2  AU ) and it completes an orbit every 11.86 years. This is approximately two-fifths the orbital period of Saturn, forming a near orbital resonance . The orbital plane of Jupiter is inclined 1.30° compared to Earth. Because the eccentricity of its orbit is 0.049, Jupiter is slightly over 75 million km nearer the Sun at perihelion than aphelion , which means that its orbit

9042-437: The Sun's planets to form, and its inward migration during the primordial phase of the Solar System affected much of the formation history of the other planets. Jupiter's atmosphere consists of 76% hydrogen and 24% helium by mass, with a denser interior. It contains trace elements like carbon , oxygen , sulfur , neon , ammonia , water vapour , phosphine , hydrogen sulfide , and hydrocarbons . Jupiter's helium abundance

9179-412: The Sun. This changed the direction of migration, causing them to migrate away from the Sun and out of the inner system to their current locations. All of this happened over a period of 3–6   million years, with the final migration of Jupiter occurring over several hundred thousand years. Jupiter's migration from the inner solar system eventually allowed the inner planets—including Earth—to form from

9316-500: The angle to the Sun, whereas the other measures spin rate and clocking. A cylindrical radioisotope thermoelectric generator (RTG) protrudes in the plane of the triangle from one vertex of the triangle. The RTG provided 245.7  W of power at launch, and was predicted to drop approximately 3.5  W every year, decaying to 202 W by the time of its encounter with the Plutonian system in 2015 and will decay too far to power

9453-427: The anti-solar face of the spacecraft (the ram direction), and an electronics box within the spacecraft. The detector contains fourteen polyvinylidene difluoride (PVDF) panels, twelve science and two reference, which generate voltage when impacted. Effective collecting area is 0.125 m (1.35 sq ft). No dust counter has operated past the orbit of Uranus ; models of dust in the outer Solar System, especially

9590-497: The argon snow line, which may be as far as 40 AU (6.0 billion km; 3.7 billion mi). Having formed at one of these extreme distances, Jupiter would then have, over a roughly 700,000-year period, migrated inwards to its current location, during an epoch approximately 2–3 million years after the planet began to form. In this model, Saturn, Uranus, and Neptune would have formed even further out than Jupiter, and Saturn would also have migrated inwards. Jupiter

9727-550: The asteroid to scientific and engineering fanfare. In November 2001, New Horizons was officially selected for funding as part of the New Frontiers program. However, the new NASA Administrator appointed by the Bush administration , Sean O'Keefe , was not supportive of New Horizons and effectively canceled it by not including it in NASA's budget for 2003. NASA's Associate Administrator for

9864-577: The atmospheres, surfaces, interiors, and environments of Pluto and its moons. It will also study other objects in the Kuiper belt. "By way of comparison, New Horizons gathered 5,000 times as much data at Pluto as Mariner did at the Red Planet ." Some of the questions the mission attempts to answer are: What is Pluto's atmosphere made of and how does it behave? What does its surface look like? Are there large geological structures? How do solar wind particles interact with Pluto's atmosphere? Specifically,

10001-502: The body under the dish. The receivers are low-power designs. The system can be controlled to power both TWTAs at the same time, and transmit a dual-polarized downlink signal to the DSN that nearly doubles the downlink rate. DSN tests early in the mission with this dual polarization combining technique were successful, and the capability was declared to be operational (when the spacecraft power budget permits both TWTAs to be powered). In addition to

10138-409: The chromophores from view. Jupiter has a low axial tilt , thus ensuring that the poles always receive less solar radiation than the planet's equatorial region. Convection within the interior of the planet transports energy to the poles, balancing out temperatures at the cloud layer. A well-known feature of Jupiter is the Great Red Spot , a persistent anticyclonic storm located 22° south of

10275-481: The cloud layer gradually transitions to a liquid in deeper layers, possibly resembling something akin to an ocean of liquid hydrogen and other supercritical fluids. Physically, the gas gradually becomes hotter and denser as depth increases. Rain-like droplets of helium and neon precipitate downward through the lower atmosphere, depleting the abundance of these elements in the upper atmosphere. Calculations suggest that helium drops separate from metallic hydrogen at

10412-414: The cold outer Solar System, the louvers are closed, and the shunt regulator reroutes power to electric heaters . New Horizons has both spin-stabilized (cruise) and three-axis stabilized (science) modes controlled entirely with hydrazine monopropellant . Additional post launch delta- v of over 290 m/s (1,000 km/h; 650 mph) is provided by a 77 kg (170 lb) internal tank. Helium

10549-545: The communications channels. These are small enough to fit on a single card. Because there are two redundant communications subsystems, there are two, identical REX circuit boards. On September 24, 2005, the spacecraft arrived at the Kennedy Space Center on board a C-17 Globemaster III for launch preparations. The launch of New Horizons was originally scheduled for January 11, 2006, but was initially delayed until January 17, 2006, to allow for borescope inspections of

10686-455: The data to Earth. Data storage is done on two low-power solid-state recorders (one primary, one backup) holding up to 8  gigabyte s each. Because of the extreme distance from Pluto and the Kuiper belt, only one buffer load at those encounters can be saved. This is because New Horizons would require approximately 16 months after leaving the vicinity of Pluto to transmit the buffer load back to Earth. At Pluto's distance, radio signals from

10823-429: The decade to follow, which became a mission to 486958 Arrokoth . It is the fifth space probe to achieve the escape velocity needed to leave the Solar System . On January 19, 2006, New Horizons was launched from Cape Canaveral Air Force Station by an Atlas V rocket directly into an Earth-and-solar escape trajectory with a speed of about 16.26 km/s (10.10 mi/s; 58,500 km/h; 36,400 mph). It

10960-489: The equator. It was first observed in 1831, and possibly as early as 1665. Images by the Hubble Space Telescope have shown two more "red spots" adjacent to the Great Red Spot. The storm is visible through Earth-based telescopes with an aperture of 12 cm or larger. The storm rotates counterclockwise, with a period of about six days. The maximum altitude of this storm is about 8 km (5 mi) above

11097-571: The equivalent radiation of 80% the average annual dosage in North America from background radiation over an area with a radius of 105 km (65 mi). The spacecraft carries two computer systems: the Command and Data Handling system and the Guidance and Control processor. Each of the two systems is duplicated for redundancy , for a total of four computers. The processor used for its flight computers

11234-478: The etymology of Zeus ('sky father'). The English equivalent, Jove , is known to have come into use as a poetic name for the planet around the 14th century. Jovian is the adjectival form of Jupiter. The older adjectival form jovial , employed by astrologers in the Middle Ages , has come to mean 'happy' or 'merry', moods ascribed to Jupiter's influence in astrology . The original Greek deity Zeus supplies

11371-438: The existence of a " hydrogen wall " at the outer edges of the Solar System . This "wall" was first detected in 1992 by the two Voyager spacecraft . New Horizons is traveling through the Kuiper belt; it is 60.99  AU (9.12  billion   km ; 5.67 billion  mi ) from Earth and 60.37  AU (9.03  billion   km ; 5.61 billion  mi ) from the Sun as of November 2024. NASA has announced it

11508-492: The far and extreme ultraviolet (from 50– 180  nm ), over 32 view fields. Its goal is to determine the composition of Pluto's atmosphere. This Alice instrument is derived from another Alice aboard ESA 's Rosetta spacecraft. The instrument has a mass of 4.4 kg and draws 4.4 watts of power. Its primary role is to determine the relative concentrations of various elements and isotopes in Pluto's atmosphere. In August 2018, NASA confirmed, based on results by Alice on

11645-474: The fluid, metallic hydrogen core. The solar wind interacts with the magnetosphere , extending it outward and affecting Jupiter's orbit. Jupiter is surrounded by a faint system of planetary rings that were discovered in 1979 by Voyager 1 and further investigated by the Galileo orbiter in the 1990s. The Jovian ring system consists mainly of dust and has three main segments: an inner torus of particles known as

11782-515: The forward-facing side of the high-gain antenna's secondary reflector. The forward low-gain antenna is stacked atop the feed of the medium-gain antenna. The aft low-gain antenna is mounted within the launch adapter at the rear of the spacecraft. This antenna was used only for early mission phases near Earth, just after launch and for emergencies if the spacecraft had lost attitude control. New Horizons recorded scientific instrument data to its solid-state memory buffer at each encounter, then transmitted

11919-489: The four largest moons of Jupiter (now known as the Galilean moons ) using a telescope. This is thought to be the first telescopic observation of moons other than Earth's. Just one day after Galileo, Simon Marius independently discovered moons around Jupiter, though he did not publish his discovery in a book until 1614. It was Marius's names for the major moons, however, that stuck: Io, Europa, Ganymede, and Callisto. The discovery

12056-426: The full dynamic range of brightness information available from the raw LORRI images files. Solar Wind Around Pluto (SWAP) is a toroidal electrostatic analyzer and retarding potential analyzer (RPA), that makes up one of the two instruments comprising New Horizons ' Plasma and high-energy particle spectrometer suite (PAM), the other being PEPSSI. SWAP measures particles of up to 6.5 keV and, because of

12193-400: The halo, a relatively bright main ring, and an outer gossamer ring. These rings appear to be made of dust, whereas Saturn's rings are made of ice. The main ring is most likely made out of material ejected from the satellites Adrastea and Metis , which is drawn into Jupiter because of the planet's strong gravitational influence. New material is added by additional impacts. In a similar way,

12330-420: The halo, a relatively bright main ring, and an outer gossamer ring. The rings have a reddish colour in visible and near-infrared light. The age of the ring system is unknown, possibly dating back to Jupiter's formation. At least 95 moons orbit the planet; the four largest moons — Io , Europa , Ganymede , and Callisto —orbit within the magnetosphere, and were discovered by Galileo Galilei in 1610. Ganymede,

12467-516: The hydrogen. The orange and brown colours in the clouds of Jupiter are caused by upwelling compounds that change colour when they are exposed to ultraviolet light from the Sun. The exact makeup remains uncertain, but the substances are thought to be made up of phosphorus, sulfur or possibly hydrocarbons. These colourful compounds, known as chromophores , mix with the warmer clouds of the lower deck. The light-coloured zones are formed when rising convection cells form crystallising ammonia that hides

12604-515: The largest of the four, is larger than the planet Mercury . Since 1973, Jupiter has been visited by nine robotic probes : seven flybys and two dedicated orbiters, with two more en route. In both the ancient Greek and Roman civilizations, Jupiter was named after the chief god of the divine pantheon : Zeus to the Greeks and Jupiter to the Romans. The International Astronomical Union formally adopted

12741-455: The last recorded data from the Pluto flyby was received from New Horizons . Having completed its flyby of Pluto, New Horizons then maneuvered for a flyby of Kuiper belt object 486958 Arrokoth (then nicknamed Ultima Thule ), which occurred on January 1, 2019, when it was 43.4  AU (6.49  billion   km ; 4.03 billion  mi ) from the Sun . In August 2018, NASA cited results by Alice on New Horizons to confirm

12878-520: The late 1800s showed it to be approximately 41,000 km (25,500 mi) across. As of 2015 , the storm was measured at approximately 16,500 by 10,940 km (10,250 by 6,800 mi), and was decreasing in length by about 930 km (580 mi) per year. In October 2021, a Juno flyby mission measured the depth of the Great Red Spot, putting it at around 300–500 kilometres (190–310 miles). Juno missions found several cyclone groups at Jupiter's poles. The northern group contains nine cyclones, with

13015-401: The magnetosphere, which protects them from solar wind. The volcanoes on the moon Io emit large amounts of sulfur dioxide , forming a gas torus along its orbit. The gas is ionized in Jupiter's magnetosphere , producing sulfur and oxygen ions . They, together with hydrogen ions originating from the atmosphere of Jupiter, form a plasma sheet in Jupiter's equatorial plane. The plasma in

13152-474: The mass, energy and distribution of charged particles around Pluto, and is also able to differentiate between protons , electrons , and other heavy ions . Alice is an ultraviolet imaging spectrometer that is one of two photographic instruments comprising New Horizons ' Pluto Exploration Remote Sensing Investigation (PERSI); the other being the Ralph telescope. It resolves 1,024 wavelength bands in

13289-641: The mission's science objectives are to: The spacecraft is comparable in size and general shape to a grand piano and has been compared to a piano glued to a cocktail bar-sized satellite dish. As a point of departure, the team took inspiration from the Ulysses spacecraft, which also carried a radioisotope thermoelectric generator (RTG) and dish on a box-in-box structure through the outer Solar System. Many subsystems and components have flight heritage from APL's CONTOUR spacecraft, which in turn had heritage from APL's TIMED spacecraft. New Horizons ' body forms

13426-420: The moons Thebe and Amalthea are believed to produce the two distinct components of the dusty gossamer ring. There is evidence of a fourth ring that may consist of collisional debris from Amalthea that is strung along the same moon's orbit. Jupiter is the only planet whose barycentre with the Sun lies outside the volume of the Sun, though by 7% of the Sun's radius. The average distance between Jupiter and

13563-404: The name Jupiter for the planet in 1976 and has since named its newly discovered satellites for the god's lovers, favourites, and descendants. The planetary symbol for Jupiter, [REDACTED] , descends from a Greek zeta with a horizontal stroke , ⟨Ƶ⟩ , as an abbreviation for Zeus . In Latin, Iovis is the genitive case of Iuppiter , i.e. Jupiter. It is associated with

13700-458: The planet collapsed directly from the gaseous protoplanetary disk , it was expected to completely lack a core, consisting instead of a denser and denser fluid (predominantly molecular and metallic hydrogen) all the way to the centre. Data from the Juno mission showed that Jupiter has a diffuse core that mixes into its mantle, extending for 30–50% of the planet's radius, and comprising heavy elements with

13837-465: The planet were obtained. A small telescope will usually show Jupiter's four Galilean moons and the cloud belts across Jupiter's atmosphere . A larger telescope with an aperture of 4–6 inches (10–15 cm) will show Jupiter's Great Red Spot when it faces Earth. Observation of Jupiter dates back to at least the Babylonian astronomers of the 7th or 8th century BC. The ancient Chinese knew Jupiter as

13974-457: The planet, the interaction of the magnetosphere with the solar wind generates a bow shock . Surrounding Jupiter's magnetosphere is a magnetopause , located at the inner edge of a magnetosheath —a region between it and the bow shock. The solar wind interacts with these regions, elongating the magnetosphere on Jupiter's lee side and extending it outward until it nearly reaches the orbit of Saturn. The four largest moons of Jupiter all orbit within

14111-399: The polar regions of Jupiter. As a result, radio waves are generated through a cyclotron maser mechanism , and the energy is transmitted out along a cone-shaped surface. When Earth intersects this cone, the radio emissions from Jupiter can exceed the radio output of the Sun. Jupiter has a faint planetary ring system composed of three main segments: an inner torus of particles known as

14248-467: The present-day planet. Other models predict Jupiter forming at distances much farther out, such as 18 AU (2.7 billion km; 1.7 billion mi). According to the Nice model , the infall of proto- Kuiper belt objects over the first 600 million years of Solar System history caused Jupiter and Saturn to migrate from their initial positions into a 1:2 resonance, which caused Saturn to shift into

14385-504: The probe on a solar-escape trajectory at 16.26 kilometers per second (58,536 km/h; 36,373 mph). New Horizons took only nine hours to pass the Moon's orbit. Although there were backup launch opportunities in February 2006 and February 2007, only the first twenty-three days of the 2006 window permitted the Jupiter flyby. Any launch outside that period would have forced the spacecraft to fly

14522-402: The probe runs on Nucleus RTOS operating system. There have been two "safing" events, that sent the spacecraft into safe mode : Communication with the spacecraft is via X band . The craft had a communication rate of 38 kbit/s at Jupiter; at Pluto's distance, a rate of approximately 1  kbit/s per transmitter was expected. Besides the low data rate, Pluto's distance also causes

14659-415: The proto-Jupiter grew larger than 50 Earth masses it created a gap in the solar nebula. Thereafter, the growing planet reached its final mass in 3–4   million years. Since Jupiter is made of the same elements as the Sun (hydrogen and helium) it has been suggested that the Solar System might have been early in its formation a system of multiple protostars , which are quite common, with Jupiter being

14796-411: The radius of the Sun, and its mass is one thousandth the mass of the Sun , as the densities of the two bodies are similar. A " Jupiter mass " ( M J or M Jup ) is used as a unit to describe masses of other objects, particularly extrasolar planets and brown dwarfs . For example, the extrasolar planet HD 209458 b has a mass of 0.69   M J , while the brown dwarf Gliese 229 b has

14933-467: The reduced wattage; still, not all instruments can operate simultaneously. The Department of Energy transferred the space battery program from Ohio to Argonne in 2002 because of security concerns. The amount of radioactive plutonium in the RTG is about one-third the amount on board the Cassini–Huygens probe when it launched in 1997. The Cassini launch had been protested by multiple organizations, due to

15070-582: The region of the heavens opposite Jupiter's position in the night sky. These beliefs survive in some Taoist religious practices and in the East Asian zodiac's twelve animals. The Chinese historian Xi Zezong has claimed that Gan De , an ancient Chinese astronomer , reported a small star "in alliance" with the planet, which may indicate a sighting of one of Jupiter's moons with the unaided eye. If true, this would predate Galileo's discovery by nearly two millennia. A 2016 paper reports that trapezoidal rule

15207-416: The risk of such a large amount of plutonium being released into the atmosphere in case of an accident. The United States Department of Energy estimated the chances of a launch accident that would release radiation into the atmosphere at 1 in 350, and monitored the launch because of the inclusion of an RTG on board. It was estimated that a worst-case scenario of total dispersal of on-board plutonium would spread

15344-405: The root zeno- , which is used to form some Jupiter-related words, such as zenography . Jupiter is believed to be the oldest planet in the Solar System, having formed just one million years after the Sun and roughly 50 million years before Earth. Current models of Solar System formation suggest that Jupiter formed at or beyond the snow line : a distance from the early Sun where the temperature

15481-459: The rubble. There are several unresolved issues with the grand tack hypothesis. The resulting formation timescales of terrestrial planets appear to be inconsistent with the measured elemental composition. Jupiter would likely have settled into an orbit much closer to the Sun if it had migrated through the solar nebula . Some competing models of Solar System formation predict the formation of Jupiter with orbital properties that are close to those of

15618-559: The same way as terrestrial thunderstorms, driven by the heat rising from the interior. The Juno mission revealed the presence of "shallow lightning" which originates from ammonia-water clouds relatively high in the atmosphere. These discharges carry "mushballs" of water-ammonia slushes covered in ice, which fall deep into the atmosphere. Upper-atmospheric lightning has been observed in Jupiter's upper atmosphere, bright flashes of light that last around 1.4   milliseconds. These are known as "elves" or "sprites" and appear blue or pink due to

15755-400: The second but failed protostar. But the Solar System never developed into a system of multiple stars and Jupiter does not qualify as a protostar or brown dwarf since it does not have enough mass to fuse hydrogen. According to the " grand tack hypothesis ", Jupiter began to form at a distance of roughly 3.5  AU (520 million  km ; 330 million  mi ) from the Sun. As

15892-435: The sheet co-rotates with the planet, causing deformation of the dipole magnetic field into that of a magnetodisk. Electrons within the plasma sheet generate a strong radio signature, with short, superimposed bursts in the range of 0.6–30  MHz that are detectable from Earth with consumer-grade shortwave radio receivers . As Io moves through this torus, the interaction generates Alfvén waves that carry ionized matter into

16029-434: The short term, it has maintained its general position in the atmosphere for more than 15 years. It may be a giant vortex similar to the Great Red Spot, and appears to be quasi-stable like the vortices in Earth's thermosphere. This feature may be formed by interactions between charged particles generated from Io and the strong magnetic field of Jupiter, resulting in a redistribution of heat flow. Jupiter's magnetic field

16166-615: The small ones (previously used on Cassini and the Voyager spacecraft) are used primarily for attitude control and spinup/spindown maneuvers. Two star cameras are used to measure the spacecraft attitude. They are mounted on the face of the spacecraft and provide attitude information while in spin-stabilized or 3-axis mode. In between the time of star camera readings, spacecraft orientation is provided by dual redundant miniature inertial measurement units . Each unit contains three solid-state gyroscopes and three accelerometers . Two Adcole Sun sensors provide attitude determination. One detects

16303-439: The space probe back to Earth took four hours and 25 minutes to traverse 4.7 billion km of space. Part of the reason for the delay between the gathering of and transmission of data is that all of the New Horizons instrumentation is body-mounted. In order for the cameras to record data, the entire probe must turn, and the one-degree-wide beam of the high-gain antenna was not pointing toward Earth. Previous spacecraft, such as

16440-554: The spacecraft to Earth, the SCET of an event on the spacecraft can be defined as equal to the ERT (Earth-Received Time) minus the OWLT (One-Way Light Time). For events transmitted from Earth to the spacecraft, the calculation is TRM (transmission time) plus OWLT. For example, if a signal were received on Earth at exactly 11:00 UTC from a spacecraft showing that it had just completed a maneuvering thrust, but

16577-412: The spacecraft was four light-hours away from Earth (the distance of the New Horizons spacecraft at one point as it approaches Pluto ), the SCET time of the thrust maneuver would have been four hours earlier, at 07:00. Spacecraft Event Time in UTC is also known as Orbiter UTC , and Earth-received time as Ground UTC . Since it takes time for a radio transmission to reach a spacecraft from Earth ,

16714-434: The surrounding cloud tops. The Spot's composition and the source of its red colour remain uncertain, although photodissociated ammonia reacting with acetylene is a likely explanation. The Great Red Spot is larger than the Earth. Mathematical models suggest that the storm is stable and will be a permanent feature of the planet. However, it has significantly decreased in size since its discovery. Initial observations in

16851-548: The tenuous solar wind at Pluto's distance, the instrument is designed with the largest aperture of any such instrument ever flown. Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) is a time of flight ion and electron sensor that makes up one of the two instruments comprising New Horizons ' plasma and high-energy particle spectrometer suite (PAM), the other being SWAP. Unlike SWAP, which measures particles of up to 6.5 keV, PEPSSI goes up to 1 MeV. The PEPSSI sensor has been designed to measure

16988-497: The time of its formation, Jupiter was hotter and was about twice its current diameter. Before the early 21st century, most scientists proposed one of two scenarios for the formation of Jupiter. If the planet accreted first as a solid body, it would consist of a dense core , a surrounding layer of fluid metallic hydrogen (with some helium) extending outward to about 80% of the radius of the planet, and an outer atmosphere consisting primarily of molecular hydrogen . Alternatively, if

17125-471: The transmitters in the 2030s. There are no onboard batteries since RTG output is predictable, and load transients are handled by a capacitor bank and fast circuit breakers. As of January 2019, the power output of the RTG is about 190  W . The RTG, model " GPHS-RTG ", was originally a spare from the Cassini mission. The RTG contains 9.75 kg (21.5 lb) of plutonium-238 oxide pellets. Each pellet

17262-479: The universe. The dust counter is named for Venetia Burney , who first suggested the name "Pluto" at the age of 11. A thirteen-minute short film about the VBSDC garnered an Emmy Award for student achievement in 2006. The Radio Science Experiment (REX) used an ultrastable crystal oscillator (essentially a calibrated crystal in a miniature oven ) and some additional electronics to conduct radio science investigations using

17399-457: The usual operation of a spacecraft is controlled with an uploaded command script containing SCET markers to ensure a certain timeline of events. Because of the delay between the sending of instructions from Earth and their receipt and execution by the spacecraft, real-time commanding of robotic spacecraft is done rarely: usually only in response to an emergency event, when changes in spacecraft operations must be made as soon as possible. For example,

17536-511: The young planet accreted mass, its interaction with the gas disk orbiting the Sun and the orbital resonances from Saturn caused it to migrate inward. This upset the orbits of several super-Earths orbiting closer to the Sun, causing them to collide destructively. Saturn would later have begun to migrate inwards at a faster rate than Jupiter until the two planets became captured in a 3:2 mean motion resonance at approximately 1.5 AU (220 million km; 140 million mi) from

17673-574: Was a major point in favour of the heliocentric theory of the motions of the planets by Nicolaus Copernicus ; Galileo's outspoken support of the Copernican theory led to him being tried and condemned by the Inquisition . In the autumn of 1639, the Neapolitan optician Francesco Fontana tested a 22-palm telescope of his own making and discovered the characteristic bands of the planet's atmosphere. During

17810-512: Was achieved. Although Jupiter would need to be about 75 times more massive to fuse hydrogen and become a star , its diameter is sufficient as the smallest red dwarf may be slightly larger in radius than Saturn. Jupiter radiates more heat than it receives through solar radiation, due to the Kelvin–Helmholtz mechanism within its contracting interior. This process causes Jupiter to shrink by about 1 mm (0.039 in) per year. At

17947-468: Was based largely on Stern's work since Pluto 350 and involved most of the team from Pluto Kuiper Express . The New Horizons proposal was one of five that were officially submitted to NASA. It was later selected as one of two finalists to be subject to a three-month concept study in June 2001. The other finalist, POSSE (Pluto and Outer Solar System Explorer), was a separate but similar Pluto mission concept by

18084-652: Was finally able to start building the spacecraft and its instruments, with a planned launch in January 2006 and arrival at Pluto in 2015. Alice Bowman became Mission Operations Manager (MOM). New Horizons is the first mission in NASA's New Frontiers mission category, larger and more expensive than the Discovery missions but smaller than the missions of the Flagship Program. The cost of the mission, including spacecraft and instrument development, launch vehicle, mission operations, data analysis, and education/public outreach,

18221-623: Was originally planned as a voyage to the only unexplored planet in the Solar ;System. When the spacecraft was launched, Pluto was still classified as a planet , later to be reclassified as a dwarf planet by the International Astronomical Union (IAU). Some members of the New Horizons team, including Alan Stern, disagree with the IAU definition and still describe Pluto as the ninth planet. Pluto's satellites Nix and Hydra also have

18358-406: Was published in the summer of 2002. New Horizons topped the list of projects considered the highest priority among the scientific community in the medium-size category; ahead of missions to the Moon, and even Jupiter. Weiler stated that it was a result that "[his] administration was not going to fight". Funding for the mission was finally secured following the publication of the report. Stern's team

18495-447: Was sufficiently cold for volatiles such as water to condense into solids. First forming a solid core, the planet then accumulated its gaseous atmosphere. Therefore, the planet must have formed before the solar nebula was fully dispersed. During its formation, Jupiter's mass gradually increased until it had 20 times the mass of the Earth, approximately half of which was made up of silicates, ices and other heavy-element constituents. When

18632-513: Was the fastest (average speed with respect to Earth) human-made object ever launched from Earth. It is not the fastest speed recorded for a spacecraft, which, as of 2023, is that of the Parker Solar Probe . After a brief encounter with asteroid 132524 APL , New Horizons proceeded to Jupiter , making its closest approach on February 28, 2007, at a distance of 2.3 million kilometers (1.4 million miles). The Jupiter flyby provided

18769-562: Was used by Babylonians before 50 BC for integrating the velocity of Jupiter along the ecliptic . In his 2nd century work the Almagest , the Hellenistic astronomer Claudius Ptolemaeus constructed a geocentric planetary model based on deferents and epicycles to explain Jupiter's motion relative to Earth, giving its orbital period around Earth as 4332.38 days, or 11.86 years. In 1610, Italian polymath Galileo Galilei discovered

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