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142-526: Many common everyday services for terrestrial use such as weather forecasting , remote sensing , satellite navigation systems, satellite television , and some long-distance communications systems critically rely on space infrastructure . Of the sciences, astronomy and Earth science benefit from space technology. New technologies originating with or accelerated by space-related endeavors are often subsequently exploited in other economic activities. The first country on Earth to put any technology into space

284-404: A Delta II rocket exploded 13 seconds after launch on January 17, 1997, there were reports of store windows 10 miles (16 km) away being broken by the blast. Space is a fairly predictable environment, but there are still risks of accidental depressurization and the potential failure of equipment, some of which may be very newly developed. Earth Earth is the third planet from

426-455: A Grand Tour to study the outer planets led NASA to begin work on a mission during the early 1970s. Information gathered by the Pioneer 10 spacecraft helped engineers design Voyager to better cope with the intense radiation around Jupiter. Still, shortly before launch, strips of kitchen-grade aluminum foil were applied to certain cables to improve radiation shielding. Initially, Voyager 1

568-533: A circumstellar disk , and then the planets grow out of that disk with the Sun. A nebula contains gas, ice grains, and dust (including primordial nuclides ). According to nebular theory , planetesimals formed by accretion , with the primordial Earth being estimated as likely taking anywhere from 70 to 100 million years to form. Estimates of the age of the Moon range from 4.5 Ga to significantly younger. A leading hypothesis

710-454: A choice of either doing a Pluto or Titan flyby; exploration of the moon took priority because it was known to have a substantial atmosphere. Voyager 1 studied the weather, magnetic fields , and rings of the two gas giants and was the first probe to provide detailed images of their moons. As part of the Voyager program and like its sister craft Voyager 2 , the spacecraft's extended mission

852-492: A common barycenter every 27.32 days relative to the background stars. When combined with the Earth–Moon system's common orbit around the Sun, the period of the synodic month , from new moon to new moon, is 29.53 days. Viewed from the celestial north pole , the motion of Earth, the Moon, and their axial rotations are all counterclockwise . Viewed from a vantage point above the Sun and Earth's north poles, Earth orbits in

994-542: A counterclockwise direction about the Sun. The orbital and axial planes are not precisely aligned: Earth's axis is tilted some 23.44 degrees from the perpendicular to the Earth–Sun plane (the ecliptic ), and the Earth-Moon plane is tilted up to ±5.1 degrees against the Earth–Sun plane. Without this tilt, there would be an eclipse every two weeks, alternating between lunar eclipses and solar eclipses . The Hill sphere , or

1136-510: A distance of 94 AU (8,700 million mi) from the Sun. On March 31, 2006, amateur radio operators from AMSAT in Germany tracked and received radio waves from Voyager 1 using the 20-metre (66 ft) dish at Bochum with a long integration technique. Retrieved data was checked and verified against data from the Deep Space Network station at Madrid, Spain. This seems to be

1278-420: A full rotation about its axis so that the Sun returns to the meridian . The orbital speed of Earth averages about 29.78 km/s (107,200 km/h; 66,600 mph), which is fast enough to travel a distance equal to Earth's diameter, about 12,742 km (7,918 mi), in seven minutes, and the distance from Earth to the Moon, 384,400 km (238,900 mi), in about 3.5 hours. The Moon and Earth orbit

1420-421: A globe-spanning mid-ocean ridge system. At Earth's polar regions , the ocean surface is covered by seasonally variable amounts of sea ice that often connects with polar land, permafrost and ice sheets , forming polar ice caps . Earth's land covers 29.2%, or 149 million km (58 million sq mi) of Earth's surface. The land surface includes many islands around the globe, but most of

1562-486: A new region referred to as a "cosmic purgatory". Within this stagnation region, charged particles streaming from the Sun slow and turn inward, and the Solar System's magnetic field is doubled in strength as interstellar space appears to be applying pressure. Energetic particles originating in the Solar System decline by nearly half, while the detection of high-energy electrons from outside increases 100-fold. The inner edge of

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1704-456: Is a chemically distinct silicate solid crust, which is underlain by a highly viscous solid mantle. The crust is separated from the mantle by the Mohorovičić discontinuity . The thickness of the crust varies from about 6 kilometres (3.7 mi) under the oceans to 30–50 km (19–31 mi) for the continents. The crust and the cold, rigid, top of the upper mantle are collectively known as

1846-509: Is an improved version of the one that was used in the 1970s Viking orbiters . The Attitude and Articulation Control Subsystem (AACS) controls the spacecraft orientation (its attitude ). It keeps the high-gain antenna pointing towards the Earth , controls attitude changes, and points the scan platform. The custom-built AACS systems on both Voyagers are the same. The Voyager 1 probe was launched on September 5, 1977, from Launch Complex 41 at

1988-483: Is approximately 9.8 m/s (32 ft/s ). Local differences in topography, geology, and deeper tectonic structure cause local and broad regional differences in Earth's gravitational field, known as gravity anomalies . The main part of Earth's magnetic field is generated in the core, the site of a dynamo process that converts the kinetic energy of thermally and compositionally driven convection into electrical and magnetic field energy. The field extends outwards from

2130-435: Is at least somewhat humid and covered by vegetation , while large sheets of ice at Earth's polar deserts retain more water than Earth's groundwater , lakes, rivers and atmospheric water combined. Earth's crust consists of slowly moving tectonic plates , which interact to produce mountain ranges, volcanoes , and earthquakes. Earth has a liquid outer core that generates a magnetosphere capable of deflecting most of

2272-517: Is contained in 3.45 billion-year-old Australian rocks showing fossils of microorganisms . During the Neoproterozoic , 1000 to 539 Ma , much of Earth might have been covered in ice. This hypothesis has been termed " Snowball Earth ", and it is of particular interest because it preceded the Cambrian explosion , when multicellular life forms significantly increased in complexity. Following

2414-406: Is currently at a distance of 145.11 astronomical units (2.1708 × 10 km; 1.3489 × 10 mi) (21.708 billion kilometers; 13.489 billion miles) from Earth as of January 1, 2019. All launch vehicles contain a huge amount of energy that is needed for some part of it to reach orbit. There is therefore some risk that this energy can be released prematurely and suddenly, with significant effects. When

2556-452: Is farthest out from its center of mass at its equatorial bulge, the summit of the volcano Chimborazo in Ecuador (6,384.4 km or 3,967.1 mi) is its farthest point out. Parallel to the rigid land topography the ocean exhibits a more dynamic topography . To measure the local variation of Earth's topography, geodesy employs an idealized Earth producing a geoid shape. Such a shape

2698-516: Is gained if the ocean is idealized, covering Earth completely and without any perturbations such as tides and winds. The result is a smooth but irregular geoid surface, providing a mean sea level (MSL) as a reference level for topographic measurements. Earth's surface is the boundary between the atmosphere, and the solid Earth and oceans. Defined in this way, it has an area of about 510 million km (197 million sq mi). Earth can be divided into two hemispheres : by latitude into

2840-501: Is now slightly longer than it was during the 19th century due to tidal deceleration , each day varies between 0 and 2 ms longer than the mean solar day. Earth's rotation period relative to the fixed stars , called its stellar day by the International Earth Rotation and Reference Systems Service (IERS), is 86,164.0989 seconds of mean solar time ( UT1 ), or 23 56 4.0989 . Earth's rotation period relative to

2982-612: Is rare, though the alternative spelling Gaia has become common due to the Gaia hypothesis , in which case its pronunciation is / ˈ ɡ aɪ . ə / rather than the more classical English / ˈ ɡ eɪ . ə / . There are a number of adjectives for the planet Earth. The word "earthly" is derived from "Earth". From the Latin Terra comes terran / ˈ t ɛr ə n / , terrestrial / t ə ˈ r ɛ s t r i ə l / , and (via French) terrene / t ə ˈ r iː n / , and from

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3124-477: Is that it was formed by accretion from material loosed from Earth after a Mars -sized object with about 10% of Earth's mass, named Theia , collided with Earth. It hit Earth with a glancing blow and some of its mass merged with Earth. Between approximately 4.1 and 3.8 Ga , numerous asteroid impacts during the Late Heavy Bombardment caused significant changes to the greater surface environment of

3266-453: Is the basis for the astronomical unit (AU) and is equal to roughly 8.3 light minutes or 380 times Earth's distance to the Moon . Earth orbits the Sun every 365.2564 mean solar days , or one sidereal year . With an apparent movement of the Sun in Earth's sky at a rate of about 1°/day eastward, which is one apparent Sun or Moon diameter every 12 hours. Due to this motion, on average it takes 24 hours—a solar day—for Earth to complete

3408-457: Is tied to that of the Sun. Over the next 1.1 billion years , solar luminosity will increase by 10%, and over the next 3.5 billion years by 40%. Earth's increasing surface temperature will accelerate the inorganic carbon cycle , possibly reducing CO 2 concentration to levels lethally low for current plants ( 10  ppm for C4 photosynthesis ) in approximately 100–900 million years . A lack of vegetation would result in

3550-429: Is to locate and study the regions and boundaries of the outer heliosphere and to begin exploring the interstellar medium . Voyager 1 crossed the heliopause and entered interstellar space on August 25, 2012, making it the first spacecraft to do so. Two years later, Voyager 1 began experiencing a third wave of coronal mass ejections from the Sun that continued to at least December 15, 2014, further confirming that

3692-428: Is unable to communicate with the Earth, its digital tape recorder (DTR) can record about 67 megabytes of data for later transmission. As of 2023 , signals from Voyager 1 take more than 22 hours to reach Earth. Voyager 1 has three radioisotope thermoelectric generators (RTGs) mounted on a boom. Each MHW-RTG contains 24 pressed plutonium-238 oxide spheres. The RTGs generated about 470 W of electric power at

3834-466: The digital computers , the Flight Data Subsystem (FDS). Since the 1990s, most space probes have been equipped with completely autonomous cameras. The computer command subsystem (CCS) controls the cameras. The CCS contains fixed computer programs, such as command decoding, fault-detection and fault-correction routines, antenna pointing routines, and spacecraft sequencing routines. This computer

3976-465: The California Institute of Technology said, "Voyager has discovered a new region of the heliosphere that we had not realized was there. We're still inside, apparently. But the magnetic field now is connected to the outside. So it's like a highway letting particles in and out." The magnetic field in this region was 10 times more intense than Voyager 1 encountered before the termination shock. It

4118-522: The Cape Canaveral Air Force Station , aboard a Titan IIIE launch vehicle . The Voyager 2 probe had been launched two weeks earlier, on August 20, 1977. Despite being launched later, Voyager 1 reached both Jupiter and Saturn sooner, following a shorter trajectory. Voyager 1 ' s launch almost failed because Titan's LR-91 second stage shut down prematurely, leaving 1,200 pounds (540 kg) of propellant unburned. Recognizing

4260-566: The Milky Way and orbits about 28,000  light-years from its center. It is about 20 light-years above the galactic plane in the Orion Arm . The axial tilt of Earth is approximately 23.439281° with the axis of its orbit plane, always pointing towards the Celestial Poles . Due to Earth's axial tilt, the amount of sunlight reaching any given point on the surface varies over the course of

4402-513: The NASA Deep Space Network (DSN) to receive routine commands and to transmit data to Earth. Real-time distance and velocity data are provided by NASA and JPL . At a distance of 165.9  AU (24.8  billion   km ; 15.4 billion  mi ) from Earth as of November 2024 , it is the most distant human-made object from Earth. The probe made flybys of Jupiter , Saturn , and Saturn's largest moon , Titan . NASA had

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4544-722: The Pacific , North American , Eurasian , African , Antarctic , Indo-Australian , and South American . Other notable plates include the Arabian Plate , the Caribbean Plate , the Nazca Plate off the west coast of South America and the Scotia Plate in the southern Atlantic Ocean. The Australian Plate fused with the Indian Plate between 50 and 55 Ma . The fastest-moving plates are

4686-553: The Sun and the only astronomical object known to harbor life . This is enabled by Earth being an ocean world , the only one in the Solar System sustaining liquid surface water . Almost all of Earth's water is contained in its global ocean, covering 70.8% of Earth's crust . The remaining 29.2% of Earth's crust is land, most of which is located in the form of continental landmasses within Earth's land hemisphere . Most of Earth's land

4828-419: The asthenosphere , the solid but less-viscous part of the upper mantle that can flow and move along with the plates. As the tectonic plates migrate, oceanic crust is subducted under the leading edges of the plates at convergent boundaries. At the same time, the upwelling of mantle material at divergent boundaries creates mid-ocean ridges. The combination of these processes recycles the oceanic crust back into

4970-415: The celestial equator , this is equivalent to an apparent diameter of the Sun or the Moon every two minutes; from Earth's surface, the apparent sizes of the Sun and the Moon are approximately the same. Earth orbits the Sun, making Earth the third-closest planet to the Sun and part of the inner Solar System . Earth's average orbital distance is about 150 million km (93 million mi), which

5112-493: The equator . The mid-latitude auroras, which occur only in sunlit regions, remain a puzzle, since bombardment by electrons and ions, known to cause auroras on Earth, occurs primarily at high latitudes. Both Voyagers measured the rotation of Saturn (the length of a day) at 10 hours, 39 minutes, 24 seconds. Voyager 1 ' s mission included a flyby of Titan, Saturn's largest moon, which had long been known to have an atmosphere. Images taken by Pioneer 11 in 1979 had indicated

5254-410: The equatorial region receiving more sunlight than the polar regions) drive atmospheric and ocean currents , producing a global climate system with different climate regions , and a range of weather phenomena such as precipitation , allowing components such as nitrogen to cycle . Earth is rounded into an ellipsoid with a circumference of about 40,000 km. It is the densest planet in

5396-408: The ocean floor form the top of Earth's crust , which together with parts of the upper mantle form Earth's lithosphere . Earth's crust may be divided into oceanic and continental crust. Beneath the ocean-floor sediments, the oceanic crust is predominantly basaltic , while the continental crust may include lower density materials such as granite , sediments and metamorphic rocks. Nearly 75% of

5538-430: The precessing or moving mean March equinox (when the Sun is at 90° on the equator), is 86,164.0905 seconds of mean solar time (UT1) (23 56 4.0905 ) . Thus the sidereal day is shorter than the stellar day by about 8.4 ms. Apart from meteors within the atmosphere and low-orbiting satellites, the main apparent motion of celestial bodies in Earth's sky is to the west at a rate of 15°/h = 15'/min. For bodies near

5680-413: The sphere of gravitational influence , of Earth is about 1.5 million km (930,000 mi) in radius. This is the maximum distance at which Earth's gravitational influence is stronger than that of the more distant Sun and planets. Objects must orbit Earth within this radius, or they can become unbound by the gravitational perturbation of the Sun. Earth, along with the Solar System, is situated in

5822-490: The termination shock in February 2003. This marks the point where the solar wind slows to subsonic speeds. Some other scientists expressed doubt and discussed this in the journal Nature of November 6, 2003. The issue would not be resolved until other data became available, since Voyager 1 's solar-wind detector ceased functioning in 1990. This failure meant that termination shock detection would have to be inferred from

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5964-464: The "last ice age", covered large parts of the continents, to the middle latitudes, in ice and ended about 11,700 years ago. Chemical reactions led to the first self-replicating molecules about four billion years ago. A half billion years later, the last common ancestor of all current life arose. The evolution of photosynthesis allowed the Sun's energy to be harvested directly by life forms. The resultant molecular oxygen ( O 2 ) accumulated in

6106-406: The 35th anniversary of its launch), the date durable changes in the density of energetic particles were first detected. By this point, most space scientists had abandoned the hypothesis that a change in magnetic field direction must accompany a crossing of the heliopause; a new model of the heliopause predicted that no such change would be found. A key finding that persuaded many scientists that

6248-479: The Cambrian explosion, 535 Ma , there have been at least five major mass extinctions and many minor ones. Apart from the proposed current Holocene extinction event, the most recent was 66 Ma , when an asteroid impact triggered the extinction of non-avian dinosaurs and other large reptiles, but largely spared small animals such as insects, mammals , lizards and birds. Mammalian life has diversified over

6390-637: The Earth. Terra is also the name of the planet in some Romance languages , languages that evolved from Latin , like Italian and Portuguese , while in other Romance languages the word gave rise to names with slightly altered spellings, like the Spanish Tierra and the French Terre . The Latinate form Gæa or Gaea ( English: / ˈ dʒ iː . ə / ) of the Greek poetic name Gaia ( Γαῖα ; Ancient Greek : [ɡâi̯.a] or [ɡâj.ja] )

6532-507: The Jovian system in April 1979. The discovery of ongoing volcanic activity on the moon Io was probably the greatest surprise. It was the first time active volcanoes had been seen on another body in the Solar System. It appears that activity on Io affects the entire Jovian system . Io appears to be the primary source of matter that pervades the Jovian magnetosphere – the region of space that surrounds

6674-527: The Latin Tellus comes tellurian / t ɛ ˈ l ʊər i ə n / and telluric . The oldest material found in the Solar System is dated to 4.5682 +0.0002 −0.0004 Ga (billion years) ago. By 4.54 ± 0.04 Ga the primordial Earth had formed. The bodies in the Solar System formed and evolved with the Sun. In theory, a solar nebula partitions a volume out of a molecular cloud by gravitational collapse, which begins to spin and flatten into

6816-426: The Moon and, by inference, to that of Earth. Earth's atmosphere and oceans were formed by volcanic activity and outgassing . Water vapor from these sources condensed into the oceans, augmented by water and ice from asteroids, protoplanets , and comets . Sufficient water to fill the oceans may have been on Earth since it formed. In this model, atmospheric greenhouse gases kept the oceans from freezing when

6958-522: The Moon on July 20, 1969. The first human to walk on the lunar surface was Neil Armstrong , commander of Apollo 11 . The first space probe to land on moon South Pole of India. Chandrayaan-3 was launched aboard an LVM3-M4 rocket on 14 July 2023, at 09:05 UTC from Satish Dhawan Space Centre Second Launch Pad in Sriharikota, Andhra Pradesh, India, entering an Earth parking orbit with a perigee of 170 km (106 mi) and an apogee of 36,500 km (22,680 mi). Apollo 11

7100-605: The Moon was the Soviet vessel Lunokhod 1 on November 17, 1970, as part of the Lunokhod program . To date, the last human to stand on the Moon was Eugene Cernan , who, as part of the Apollo 17 mission, walked on the Moon in December 1972. Apollo 17 was followed by several uncrewed interplanetary missions operated by NASA. Also Technological innovations in space exploration have important effects on

7242-416: The Solar System . Of the four rocky planets , it is the largest and most massive. Earth is about eight light-minutes away from the Sun and orbits it , taking a year (about 365.25 days) to complete one revolution. Earth rotates around its own axis in slightly less than a day (in about 23 hours and 56 minutes). Earth's axis of rotation is tilted with respect to the perpendicular to its orbital plane around

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7384-418: The Solar System at 3.3 AU (310 million mi; 490 million km) per year. Each year, Voyager 1 increases its lead over Voyager 2 . Voyager 1 reached a distance of 135 AU (12.5 billion mi; 20.2 billion km) from the Sun on May 18, 2016. On September 5, 2017, that had increased to about 139.64 AU (12.980 billion mi; 20.890 billion km) from

7526-458: The Solar System's planetary-sized objects, Earth is the object with the highest density . Earth's mass is approximately 5.97 × 10   kg ( 5.970  Yg ). It is composed mostly of iron (32.1% by mass ), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%), with the remaining 1.2% consisting of trace amounts of other elements. Due to gravitational separation ,

7668-663: The Solar System, formed 4.5 billion years ago from gas and dust in the early Solar System . During the first billion years of Earth's history , the ocean formed and then life developed within it. Life spread globally and has been altering Earth's atmosphere and surface, leading to the Great Oxidation Event two billion years ago. Humans emerged 300,000 years ago in Africa and have spread across every continent on Earth. Humans depend on Earth's biosphere and natural resources for their survival, but have increasingly impacted

7810-582: The Solar System, with a sharp increase in these collisions in late August. At the same time, in late August, there was a dramatic drop in collisions with low-energy particles, which are thought to originate from the Sun. Ed Roelof, space scientist at Johns Hopkins University and principal investigator for the Low-Energy Charged Particle instrument on the spacecraft, declared that "most scientists involved with Voyager 1 would agree that [these two criteria] have been sufficiently satisfied". However,

7952-403: The Sun when the star reaches its maximum radius, otherwise, with tidal effects, it may enter the Sun's atmosphere and be vaporized. Earth has a rounded shape , through hydrostatic equilibrium , with an average diameter of 12,742 kilometres (7,918 mi), making it the fifth largest planetary sized and largest terrestrial object of the Solar System . Due to Earth's rotation it has

8094-491: The Sun, or just over 19 light-hours; at that time, Voyager 2 was 115.32 AU (10.720 billion mi; 17.252 billion km) from the Sun. Its progress can be monitored at NASA's website. On September 12, 2013, NASA officially confirmed that Voyager 1 had reached the interstellar medium in August 2012 as previously observed. The generally accepted date of arrival is August 25, 2012 (approximately 10 days before

8236-461: The Sun, producing seasons . Earth is orbited by one permanent natural satellite , the Moon , which orbits Earth at 384,400 km (1.28 light seconds) and is roughly a quarter as wide as Earth. The Moon's gravity helps stabilize Earth's axis, causes tides and gradually slows Earth's rotation . Tidal locking has made the Moon always face Earth with the same side. Earth, like most other bodies in

8378-400: The Sun. The craft thus began to enter the interstellar medium at the edge of the Solar System. Voyager 1 became the first spacecraft to cross the heliopause in August 2012, then at a distance of 121 AU (1.12 × 10  mi; 1.81 × 10  km) from the Sun, although this was not confirmed for another year. As of September 2012, sunlight took 16.89 hours to get to Voyager 1 which

8520-505: The Sun. Winds blow at high speeds on Saturn. Near the equator, the Voyagers measured winds about 500 m/s (1,100 mph). The wind blows mostly in an easterly direction. The Voyagers found aurora -like ultraviolet emissions of hydrogen at mid-latitudes in the atmosphere, and auroras at polar latitudes (above 65 degrees). The high-level auroral activity may lead to the formation of complex hydrocarbon molecules that are carried toward

8662-425: The atmosphere and due to interaction with ultraviolet solar radiation, formed a protective ozone layer ( O 3 ) in the upper atmosphere. The incorporation of smaller cells within larger ones resulted in the development of complex cells called eukaryotes . True multicellular organisms formed as cells within colonies became increasingly specialized. Aided by the absorption of harmful ultraviolet radiation by

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8804-428: The atmosphere was substantial and complex, further increasing interest. The Titan flyby occurred as the spacecraft entered the system to avoid any possibility of damage closer to Saturn compromising observations, and approached to within 6,400 km (4,000 mi), passing behind Titan as seen from Earth and the Sun. Voyager's measurement of the atmosphere's effect on sunlight and Earth-based measurement of its effect on

8946-426: The atmosphere, particularly carbon dioxide (CO 2 ), creates the conditions for both liquid surface water and water vapor to persist via the capturing of energy from the Sun's light . This process maintains the current average surface temperature of 14.76 °C (58.57 °F), at which water is liquid under normal atmospheric pressure. Differences in the amount of captured energy between geographic regions (as with

9088-450: The center, the temperature may be up to 6,000 °C (10,830 °F), and the pressure could reach 360  GPa (52 million  psi ). Because much of the heat is provided by radioactive decay, scientists postulate that early in Earth's history, before isotopes with short half-lives were depleted, Earth's heat production was much higher. At approximately 3  Gyr , twice the present-day heat would have been produced, increasing

9230-506: The constellation Ophiuchus as observed from the Earth on May 21, 2011. On December 1, 2011, it was announced that Voyager 1 had detected the first Lyman-alpha radiation originating from the Milky Way galaxy. Lyman-alpha radiation had previously been detected from other galaxies, but because of interference from the Sun, the radiation from the Milky Way was not detectable. NASA announced on December 5, 2011, that Voyager 1 had entered

9372-454: The continental crust , particularly during the early stages of Earth's history. New continental crust forms as a result of plate tectonics , a process ultimately driven by the continuous loss of heat from Earth's interior. Over the period of hundreds of millions of years, tectonic forces have caused areas of continental crust to group together to form supercontinents that have subsequently broken apart. At approximately 750 Ma , one of

9514-616: The continental surfaces are covered by sedimentary rocks, although they form about 5% of the mass of the crust. Earth's surface topography comprises both the topography of the ocean surface , and the shape of Earth's land surface. The submarine terrain of the ocean floor has an average bathymetric depth of 4 km, and is as varied as the terrain above sea level. Earth's surface is continually being shaped by internal plate tectonic processes including earthquakes and volcanism ; by weathering and erosion driven by ice, water, wind and temperature; and by biological processes including

9656-419: The core are chaotic; the magnetic poles drift and periodically change alignment. This causes secular variation of the main field and field reversals at irregular intervals averaging a few times every million years. The most recent reversal occurred approximately 700,000 years ago. The extent of Earth's magnetic field in space defines the magnetosphere . Ions and electrons of the solar wind are deflected by

9798-527: The core is primarily composed of the denser elements: iron (88.8%), with smaller amounts of nickel (5.8%), sulfur (4.5%), and less than 1% trace elements. The most common rock constituents of the crust are oxides . Over 99% of the crust is composed of various oxides of eleven elements, principally oxides containing silicon (the silicate minerals ), aluminium, iron, calcium, magnesium, potassium, or sodium. The major heat-producing isotopes within Earth are potassium-40 , uranium-238 , and thorium-232 . At

9940-463: The core, through the mantle, and up to Earth's surface, where it is, approximately, a dipole . The poles of the dipole are located close to Earth's geographic poles. At the equator of the magnetic field, the magnetic-field strength at the surface is 3.05 × 10 T , with a magnetic dipole moment of 7.79 × 10 Am at epoch 2000, decreasing nearly 6% per century (although it still remains stronger than its long time average). The convection movements in

10082-540: The data from the other instruments on board. In May 2005, a NASA press release said that the consensus was that Voyager 1 was then in the heliosheath . In a scientific session at the American Geophysical Union meeting in New Orleans on May 25, 2005, Ed Stone presented evidence that the craft crossed the termination shock in late 2004. This event is estimated to have occurred on December 15, 2004, at

10224-524: The days shorter. Above the Arctic Circle and below the Antarctic Circle there is no daylight at all for part of the year, causing a polar night , and this night extends for several months at the poles themselves. These same latitudes also experience a midnight sun , where the sun remains visible all day. By astronomical convention, the four seasons can be determined by the solstices—the points in

10366-486: The deficiency, the Centaur stage's on-board computers ordered a burn that was far longer than planned in order to compensate. Centaur extended its own burn and was able to give Voyager 1 the additional velocity it needed. At cutoff, the Centaur was only 3.4 seconds from propellant exhaustion. If the same failure had occurred during Voyager 2 ' s launch a few weeks earlier, the Centaur would have run out of propellant before

10508-441: The destructive solar winds and cosmic radiation . Earth has a dynamic atmosphere , which sustains Earth's surface conditions and protects it from most meteoroids and UV-light at entry . It has a composition of primarily nitrogen and oxygen . Water vapor is widely present in the atmosphere, forming clouds that cover most of the planet. The water vapor acts as a greenhouse gas and, together with other greenhouse gases in

10650-446: The duration of radio beeps. The first successful human spaceflight was Vostok 1 , carrying 27-year-old Soviet cosmonaut Yuri Gagarin in April 1961. The entire mission was controlled by either automatic systems or by ground control . This was because medical staff and spacecraft engineers were unsure how a human might react to weightlessness, and therefore it was decided to lock the pilot's manual controls. The first probe to impact

10792-605: The earliest known supercontinents, Rodinia , began to break apart. The continents later recombined to form Pannotia at 600–540 Ma , then finally Pangaea , which also began to break apart at 180 Ma . The most recent pattern of ice ages began about 40 Ma , and then intensified during the Pleistocene about 3 Ma . High- and middle-latitude regions have since undergone repeated cycles of glaciation and thaw, repeating about every 21,000, 41,000 and 100,000 years. The Last Glacial Period , colloquially called

10934-414: The economy, create jobs, and promote environmental sustainability, helping the field continue to grow. One of the notable interplanetary missions is Voyager 1 , the first artificial object to leave the Solar System into interstellar space on August 25, 2012. It is also the most distant artificial object from Earth. The probe passed the heliopause at 121 AU to enter interstellar space . Voyager 1

11076-481: The economy, society, and the environment. Economically, new safety features and technology have made space missions cheaper. Using reusable rockets helps companies save money because they do not need to fix or replace rockets as often. This makes space exploration more affordable and encourages more people to invest in the space industry. Socially, these new technologies have created many jobs in areas like engineering, research, and aerospace manufacturing. The growth of

11218-544: The equally large area of land under permafrost ) or deserts (33%). The pedosphere is the outermost layer of Earth's land surface and is composed of soil and subject to soil formation processes. Soil is crucial for land to be arable. Earth's total arable land is 10.7% of the land surface, with 1.3% being permanent cropland. Earth has an estimated 16.7 million km (6.4 million sq mi) of cropland and 33.5 million km (12.9 million sq mi) of pastureland. The land surface and

11360-472: The event. On this date, the spacecraft was approximately 116 AU (17.4 billion km; 10.8 billion mi) from the Sun. Voyager 1 was commanded to change its orientation to measure the sideways motion of the solar wind at that location in space in March 2011 (~33yr 6mo from launch). A test roll done in February had confirmed the spacecraft's ability to maneuver and reorient itself. The course of

11502-399: The fastest heliocentric recession speed of any spacecraft. As Voyager 1 headed for interstellar space, its instruments continued to study the Solar System. Jet Propulsion Laboratory scientists used the plasma wave experiments aboard Voyager 1 and 2 to look for the heliopause , the boundary at which the solar wind transitions into the interstellar medium . As of 2013 , the probe

11644-531: The first such amateur tracking of Voyager 1 . It was confirmed on December 13, 2010, that Voyager 1 had passed the reach of the radial outward flow of the solar wind , as measured by the Low Energy Charged Particle device. It is suspected that solar wind at this distance turns sideways because of interstellar wind pushing against the heliosphere. Since June 2010, detection of solar wind had been consistently at zero, providing conclusive evidence of

11786-638: The growth and decomposition of biomass into soil . Earth's mechanically rigid outer layer of Earth's crust and upper mantle , the lithosphere , is divided into tectonic plates . These plates are rigid segments that move relative to each other at one of three boundaries types: at convergent boundaries , two plates come together; at divergent boundaries , two plates are pulled apart; and at transform boundaries , two plates slide past one another laterally. Along these plate boundaries, earthquakes, volcanic activity , mountain-building , and oceanic trench formation can occur. The tectonic plates ride on top of

11928-404: The heat in Earth is lost through plate tectonics, by mantle upwelling associated with mid-ocean ridges . The final major mode of heat loss is through conduction through the lithosphere, the majority of which occurs under the oceans. The gravity of Earth is the acceleration that is imparted to objects due to the distribution of mass within Earth. Near Earth's surface, gravitational acceleration

12070-527: The heliopause had been crossed was an indirect measurement of an 80-fold increase in electron density, based on the frequency of plasma oscillations observed beginning on April 9, 2013, triggered by a solar outburst that had occurred in March 2012 (electron density is expected to be two orders of magnitude higher outside the heliopause than within). Weaker sets of oscillations measured in October and November 2012 provided additional data. An indirect measurement

12212-406: The land surface is taken by the four continental landmasses , which are (in descending order): Africa-Eurasia , America (landmass) , Antarctica , and Australia (landmass) . These landmasses are further broken down and grouped into the continents . The terrain of the land surface varies greatly and consists of mountains, deserts , plains , plateaus , and other landforms . The elevation of

12354-508: The land surface varies from a low point of −418 m (−1,371 ft) at the Dead Sea , to a maximum altitude of 8,848 m (29,029 ft) at the top of Mount Everest . The mean height of land above sea level is about 797 m (2,615 ft). Land can be covered by surface water , snow, ice, artificial structures or vegetation. Most of Earth's land hosts vegetation, but considerable amounts of land are ice sheets (10%, not including

12496-427: The last criterion for officially declaring that Voyager 1 had crossed the boundary, the expected change in magnetic field direction (from that of the Sun to that of the interstellar field beyond), had not been observed (the field had changed direction by only 2 degrees), which suggested to some that the nature of the edge of the heliosphere had been misjudged. On December 3, 2012, Voyager project scientist Ed Stone of

12638-399: The lithosphere, which is divided into independently moving tectonic plates. Beneath the lithosphere is the asthenosphere , a relatively low-viscosity layer on which the lithosphere rides. Important changes in crystal structure within the mantle occur at 410 and 660 km (250 and 410 mi) below the surface, spanning a transition zone that separates the upper and lower mantle. Beneath

12780-410: The loss of oxygen in the atmosphere, making current animal life impossible. Due to the increased luminosity, Earth's mean temperature may reach 100 °C (212 °F) in 1.5 billion years, and all ocean water will evaporate and be lost to space, which may trigger a runaway greenhouse effect , within an estimated 1.6 to 3 billion years. Even if the Sun were stable, a fraction of the water in

12922-456: The lowercase when it is preceded by "the", such as "the atmosphere of the earth". It almost always appears in lowercase in colloquial expressions such as "what on earth are you doing?" The name Terra / ˈ t ɛr ə / occasionally is used in scientific writing and especially in science fiction to distinguish humanity's inhabited planet from others, while in poetry Tellus / ˈ t ɛ l ə s / has been used to denote personification of

13064-497: The magnetosphere. During magnetic storms and substorms , charged particles can be deflected from the outer magnetosphere and especially the magnetotail, directed along field lines into Earth's ionosphere , where atmospheric atoms can be excited and ionized, causing an aurora . Earth's rotation period relative to the Sun—its mean solar day—is 86,400 seconds of mean solar time ( 86,400.0025 SI seconds ). Because Earth's solar day

13206-409: The magnetosphere; solar wind pressure compresses the day-side of the magnetosphere, to about 10 Earth radii, and extends the night-side magnetosphere into a long tail. Because the velocity of the solar wind is greater than the speed at which waves propagate through the solar wind, a supersonic bow shock precedes the day-side magnetosphere within the solar wind. Charged particles are contained within

13348-478: The magnetosphere; the plasmasphere is defined by low-energy particles that essentially follow magnetic field lines as Earth rotates. The ring current is defined by medium-energy particles that drift relative to the geomagnetic field, but with paths that are still dominated by the magnetic field, and the Van Allen radiation belts are formed by high-energy particles whose motion is essentially random, but contained in

13490-417: The mantle, an extremely low viscosity liquid outer core lies above a solid inner core . Earth's inner core may be rotating at a slightly higher angular velocity than the remainder of the planet, advancing by 0.1–0.5° per year, although both somewhat higher and much lower rates have also been proposed. The radius of the inner core is about one-fifth of that of Earth. The density increases with depth. Among

13632-600: The mantle. Due to this recycling, most of the ocean floor is less than 100 Ma old. The oldest oceanic crust is located in the Western Pacific and is estimated to be 200 Ma old. By comparison, the oldest dated continental crust is 4,030 Ma , although zircons have been found preserved as clasts within Eoarchean sedimentary rocks that give ages up to 4,400 Ma , indicating that at least some continental crust existed at that time. The seven major plates are

13774-548: The modern oceans will descend to the mantle , due to reduced steam venting from mid-ocean ridges. The Sun will evolve to become a red giant in about 5 billion years . Models predict that the Sun will expand to roughly 1  AU (150 million km; 93 million mi), about 250 times its present radius. Earth's fate is less clear. As a red giant, the Sun will lose roughly 30% of its mass, so, without tidal effects, Earth will move to an orbit 1.7 AU (250 million km; 160 million mi) from

13916-399: The mother of Thor . Historically, "Earth" has been written in lowercase. Beginning with the use of Early Middle English , its definite sense as "the globe" was expressed as "the earth". By the era of Early Modern English , capitalization of nouns began to prevail , and the earth was also written the Earth , particularly when referenced along with other heavenly bodies. More recently,

14058-424: The name is sometimes simply given as Earth , by analogy with the names of the other planets , though "earth" and forms with "the earth" remain common. House styles now vary: Oxford spelling recognizes the lowercase form as the more common, with the capitalized form an acceptable variant. Another convention capitalizes "Earth" when appearing as a name, such as a description of the "Earth's atmosphere", but employs

14200-412: The new region was interstellar space or an unknown region of the Solar System. At that time, the former alternative was officially confirmed. In 2013 Voyager 1 was exiting the Solar System at a speed of about 3.6 AU (330 million mi; 540 million km) per year, which is 61,602 km/h, 4.83 times the diameter of Earth (12,742 km) per hour; whereas Voyager 2 is going slower, leaving

14342-425: The newly forming Sun had only 70% of its current luminosity . By 3.5 Ga , Earth's magnetic field was established, which helped prevent the atmosphere from being stripped away by the solar wind . As the molten outer layer of Earth cooled it formed the first solid crust , which is thought to have been mafic in composition. The first continental crust , which was more felsic in composition, formed by

14484-586: The ocean may have covered Earth completely. The world ocean is commonly divided into the Pacific Ocean, Atlantic Ocean, Indian Ocean, Antarctic or Southern Ocean , and Arctic Ocean, from largest to smallest. The ocean covers Earth's oceanic crust , with the shelf seas covering the shelves of the continental crust to a lesser extent. The oceanic crust forms large oceanic basins with features like abyssal plains , seamounts , submarine volcanoes , oceanic trenches , submarine canyons , oceanic plateaus , and

14626-648: The oceanic plates, with the Cocos Plate advancing at a rate of 75 mm/a (3.0 in/year) and the Pacific Plate moving 52–69 mm/a (2.0–2.7 in/year). At the other extreme, the slowest-moving plate is the South American Plate, progressing at a typical rate of 10.6 mm/a (0.42 in/year). Earth's interior, like that of the other terrestrial planets, is divided into layers by their chemical or physical ( rheological ) properties. The outer layer

14768-581: The orbit of maximum axial tilt toward or away from the Sun—and the equinoxes , when Earth's rotational axis is aligned with its orbital axis. In the Northern Hemisphere, winter solstice currently occurs around 21 December; summer solstice is near 21 June, spring equinox is around 20 March and autumnal equinox is about 22 or 23 September. In the Southern Hemisphere, the situation is reversed, with

14910-625: The ozone layer, life colonized Earth's surface. Among the earliest fossil evidence for life is microbial mat fossils found in 3.48 billion-year-old sandstone in Western Australia , biogenic graphite found in 3.7 billion-year-old metasedimentary rocks in Western Greenland , and remains of biotic material found in 4.1 billion-year-old rocks in Western Australia. The earliest direct evidence of life on Earth

15052-469: The partial melting of this mafic crust. The presence of grains of the mineral zircon of Hadean age in Eoarchean sedimentary rocks suggests that at least some felsic crust existed as early as 4.4 Ga , only 140  Ma after Earth's formation. There are two main models of how this initial small volume of continental crust evolved to reach its current abundance: (1) a relatively steady growth up to

15194-501: The past 66 Mys , and several million years ago, an African ape species gained the ability to stand upright. This facilitated tool use and encouraged communication that provided the nutrition and stimulation needed for a larger brain, which led to the evolution of humans . The development of agriculture , and then civilization , led to humans having an influence on Earth and the nature and quantity of other life forms that continues to this day. Earth's expected long-term future

15336-541: The planet influenced by the planet's strong magnetic field . Sulfur , oxygen , and sodium , apparently erupted by Io's volcanoes and sputtered off the surface by the impact of high-energy particles, were detected at the outer edge of the magnetosphere of Jupiter . The two Voyager space probes made a number of important discoveries about Jupiter, its satellites, its radiation belts, and its never-before-seen planetary rings . The gravitational assist trajectories at Jupiter were successfully carried out by both Voyagers, and

15478-478: The planet's environment . Humanity's current impact on Earth's climate and biosphere is unsustainable , threatening the livelihood of humans and many other forms of life, and causing widespread extinctions . The Modern English word Earth developed, via Middle English , from an Old English noun most often spelled eorðe . It has cognates in every Germanic language , and their ancestral root has been reconstructed as * erþō . In its earliest attestation,

15620-421: The polar Northern and Southern hemispheres; or by longitude into the continental Eastern and Western hemispheres. Most of Earth's surface is ocean water: 70.8% or 361 million km (139 million sq mi). This vast pool of salty water is often called the world ocean , and makes Earth with its dynamic hydrosphere a water world or ocean world . Indeed, in Earth's early history

15762-490: The present day, which is supported by the radiometric dating of continental crust globally and (2) an initial rapid growth in the volume of continental crust during the Archean , forming the bulk of the continental crust that now exists, which is supported by isotopic evidence from hafnium in zircons and neodymium in sedimentary rocks. The two models and the data that support them can be reconciled by large-scale recycling of

15904-584: The probe is in interstellar space. In 2017, the Voyager team successfully fired the spacecraft's trajectory correction maneuver (TCM) thrusters for the first time since 1980, enabling the mission to be extended by two to three years. Voyager 1 ' s extended mission is expected to continue to return scientific data until at least 2025, with a maximum lifespan of until 2030. Its radioisotope thermoelectric generators (RTGs) may supply enough electric power to return engineering data until 2036. A 1960s proposal for

16046-614: The probe reached the correct trajectory. Jupiter was in a more favorable position vis-à-vis Earth during the launch of Voyager 1 than during the launch of Voyager 2 . Voyager 1 's initial orbit had an aphelion of 8.9 AU (830 million mi), just a little short of Saturn's orbit of 9.5 AU (880 million mi). Voyager 2 ' s initial orbit had an aphelion of 6.2 AU (580 million mi), well short of Saturn's orbit. Voyager 1 began photographing Jupiter in January 1979. Its closest approach to Jupiter

16188-455: The probe's radio antenna pointed toward Earth . Collectively, these instruments are part of the Attitude and Articulation Control Subsystem (AACS), along with redundant units of most instruments and eight backup thrusters. The spacecraft also included 11 scientific instruments to study celestial objects such as planets as it travels through space. The radio communication system of Voyager 1

16330-462: The probe's radio signal were used to determine the atmosphere's composition, density, and pressure. Titan's mass was also measured by observing its effect on the probe's trajectory. The thick haze prevented any visual observation of the surface, but the measurement of the atmosphere's composition, temperature, and pressure led to speculation that lakes of liquid hydrocarbons could exist on the surface. Because observations of Titan were considered vital,

16472-493: The rates of mantle convection and plate tectonics, and allowing the production of uncommon igneous rocks such as komatiites that are rarely formed today. The mean heat loss from Earth is 87 mW m , for a global heat loss of 4.42 × 10  W . A portion of the core's thermal energy is transported toward the crust by mantle plumes , a form of convection consisting of upwellings of higher-temperature rock. These plumes can produce hotspots and flood basalts . More of

16614-515: The shape of an ellipsoid , bulging at its Equator ; its diameter is 43 kilometres (27 mi) longer there than at its poles . Earth's shape also has local topographic variations; the largest local variations, like the Mariana Trench (10,925 metres or 35,843 feet below local sea level), shortens Earth's average radius by 0.17% and Mount Everest (8,848 metres or 29,029 feet above local sea level) lengthens it by 0.14%. Since Earth's surface

16756-479: The space industry also helps other industries, such as telecommunications and materials engineering, by creating new job opportunities. Environmentally, using reusable rockets helps reduce space debris. By reusing rockets, space agencies can produce less waste and lessen the impact of space missions on the environment. This approach supports cleaner space exploration and a more sustainable future. In summary, technological advances in space exploration positively affect

16898-504: The spacecraft was not changed. It rotated 70 degrees counterclockwise with respect to Earth to detect the solar wind. This was the first time the spacecraft had done any major maneuvering since the Family Portrait photograph of the planets was taken in 1990. After the first roll the spacecraft had no problem in reorienting itself with Alpha Centauri , Voyager 1 's guide star, and it resumed sending transmissions back to Earth. Voyager 1

17040-522: The spacecraft was traveling in the direction of that star, it would take 73,775 years to reach it. ( Voyager 1 is heading in the direction of the constellation Ophiuchus .) In late 2012, researchers reported that particle data from the spacecraft suggested that the probe had passed through the heliopause. Measurements from the spacecraft revealed a steady rise since May in collisions with high energy particles (above 70 MeV), which are thought to be cosmic rays emanating from supernova explosions far beyond

17182-421: The spacecraft, so it would now be complex to get them working again. Earth-side software and computers for reading the images are also no longer available. On February 17, 1998, Voyager 1 reached a distance of 69 AU (6.4 billion mi; 10.3 billion km) from the Sun and overtook Pioneer 10 as the most distant spacecraft from Earth. Traveling at about 17 km/s (11 mi/s), it has

17324-453: The stagnation region is located approximately 113 AU from the Sun. NASA announced in June 2012 that the probe was detecting changes in the environment that were suspected to correlate with arrival at the heliopause . Voyager 1 had reported a marked increase in its detection of charged particles from interstellar space, which are normally deflected by the solar winds within the heliosphere from

17466-408: The summer and winter solstices exchanged and the spring and autumnal equinox dates swapped. Voyager 1 elapsed Voyager 1 is a space probe launched by NASA on September 5, 1977, as part of the Voyager program to study the outer Solar System and the interstellar space beyond the Sun's heliosphere . It was launched 16 days after its twin, Voyager 2 . It communicates through

17608-419: The surface of the Moon was the Soviet probe Luna 2 , which made a hard landing on September 14, 1959. The far side of the Moon was first photographed on October 7, 1959, by the Soviet probe Luna 3 .s On December 24, 1968, the crew of Apollo 8 , Frank Borman , James Lovell and William Anders , became the first human beings to enter lunar orbit and see the far side of the Moon in person. Humans first landed on

17750-505: The time of launch, with the remainder being dissipated as waste heat. The power output of the RTGs declines over time due to the 87.7-year half-life of the fuel and degradation of the thermocouples, but they will continue to support some of its operations until at least 2025. Unlike Voyager's other instruments, the operation of the cameras for visible light is not autonomous, but is controlled by an imaging parameter table contained in one of

17892-464: The trajectory chosen for Voyager 1 was designed around the optimum Titan flyby, which took it below the south pole of Saturn and out of the plane of the ecliptic , ending its planetary science mission. Had Voyager 1 failed or been unable to observe Titan, Voyager 2 's trajectory would have been altered to incorporate the Titan flyby, precluding any visit to Uranus and Neptune. The trajectory Voyager 1

18034-548: The two spacecraft went on to visit Saturn and its system of moons and rings. Voyager 1 encountered Saturn in November 1980, with the closest approach on November 12, 1980, when the space probe came within 124,000 kilometres (77,000 mi) of Saturn's cloud-tops. The space probe's cameras detected complex structures in the rings of Saturn , and its remote sensing instruments studied the atmospheres of Saturn and its giant moon Titan . Voyager 1 found that about seven percent of

18176-452: The vastly larger region of space populated by bodies that orbit the Sun. The craft is presently less than one-seventh the distance to the aphelion of Sedna , and it has not yet entered the Oort cloud , the source region of long-period comets , regarded by astronomers as the outermost zone of the Solar System. In October 2020, astronomers reported a significant unexpected increase in density in

18318-463: The volume of Saturn's upper atmosphere is helium (compared with 11 percent of Jupiter's atmosphere), while almost all the rest is hydrogen . Since Saturn's internal helium abundance was expected to be the same as Jupiter's and the Sun's, the lower abundance of helium in the upper atmosphere may imply that the heavier helium may be slowly sinking through Saturn's hydrogen; that might explain the excess heat that Saturn radiates over energy it receives from

18460-456: The word eorðe was used to translate the many senses of Latin terra and Greek γῆ gē : the ground, its soil , dry land, the human world, the surface of the world (including the sea), and the globe itself. As with Roman Terra /Tellūs and Greek Gaia , Earth may have been a personified goddess in Germanic paganism : late Norse mythology included Jörð ("Earth"), a giantess often given as

18602-598: The year. This causes the seasonal change in climate, with summer in the Northern Hemisphere occurring when the Tropic of Cancer is facing the Sun, and in the Southern Hemisphere when the Tropic of Capricorn faces the Sun. In each instance, winter occurs simultaneously in the opposite hemisphere. During the summer, the day lasts longer, and the Sun climbs higher in the sky. In winter, the climate becomes cooler and

18744-446: Was at a distance of 121 AU. The apparent magnitude of the Sun from the spacecraft was −16.3 (about 30 times brighter than the full Moon). The spacecraft was traveling at 17.043 km/s (10.590 mi/s) relative to the Sun. At this rate, it would need about 17,565 years at this speed to travel a single light-year . To compare, Proxima Centauri , the closest star to the Sun, is about 4.2 light-years ( 2.65 × 10  AU ) distant. If

18886-524: Was designed to be used up to and beyond the limits of the Solar System . It has a 3.7-metre (12 ft) diameter high-gain Cassegrain antenna to send and receive radio waves via the three Deep Space Network stations on the Earth. The spacecraft normally transmits data to Earth over Deep Space Network Channel 18, using a frequency of either 2.3 GHz or 8.4 GHz, while signals from Earth to Voyager are transmitted at 2.1 GHz. When Voyager 1

19028-403: Was expected to be the last barrier before the spacecraft exited the Solar System completely and entered interstellar space. In March 2013, it was announced that Voyager 1 might have become the first spacecraft to enter interstellar space, having detected a marked change in the plasma environment on August 25, 2012. However, until September 12, 2013, it was still an open question as to whether

19170-427: Was expected to enter interstellar space "at any time". Voyager 2 was still detecting outward flow of solar wind at that point but it was estimated that in the following months or years it would experience the same conditions as Voyager 1 . The spacecraft was reported at 12.44° declination and 17.163 hours right ascension, and at an ecliptic latitude of 34.9° (the ecliptic latitude changes very slowly), placing it in

19312-411: Was followed by Apollo 12 , 14 , 15 , 16 , and 17 . Apollo 13 had a failure of the Apollo service module , but passed the far side of the Moon at an altitude of 254 kilometers (158 miles; 137 nautical miles) above the lunar surface, and 400,171 km (248,655 mi) from Earth, marking the record for the farthest humans traveled from Earth in 1970. The first robotic lunar rover to land on

19454-521: Was launched into would not have allowed it to continue on to Uranus and Neptune, but could have been altered to avoid a Titan flyby and travel from Saturn to Pluto , arriving in 1986. On February 14, 1990, Voyager 1 took the first " family portrait " of the Solar System as seen from outside, which includes the image of planet Earth known as Pale Blue Dot . Soon afterward, its cameras were deactivated to conserve energy and computer resources for other equipment. The camera software has been removed from

19596-496: Was moving with a relative velocity to the Sun of about 61,197 kilometres per hour (38,026 mph). With the velocity the probe is currently maintaining, Voyager 1 is traveling about 523 million km (325 million mi) per year, or about one light-year per 18,000 years. Scientists at the Johns Hopkins University Applied Physics Laboratory believe that Voyager 1 entered

19738-403: Was on March 5, 1979, at a distance of about 349,000 kilometres (217,000 miles) from the planet's center. Because of the greater photographic resolution allowed by a closer approach, most observations of the moons, rings, magnetic fields, and the radiation belt environment of the Jovian system were made during the 48-hour period that bracketed the closest approach. Voyager 1 finished photographing

19880-647: Was planned as Mariner 11 of the Mariner program . Due to budget cuts, the mission was reduced to a flyby of Jupiter and Saturn and renamed the Mariner Jupiter-Saturn probes. The name was changed to Voyager when the probe designs began to differ substantially from Mariner missions. Voyager 1 was built by the Jet Propulsion Laboratory (JPL). It has 16 hydrazine thrusters, three-axis stabilization gyroscopes , and referencing instruments to keep

20022-413: Was required because Voyager 1 's plasma spectrometer had stopped working in 1980. In September 2013, NASA released recordings of audio transductions of these plasma waves, the first to be measured in interstellar space. While Voyager 1 is commonly spoken of as having left the Solar System simultaneously with having left the heliosphere, the two are not the same. The Solar System is usually defined as

20164-507: Was the Soviet Union , formerly known as the "Union of Soviet Socialist Republics" (USSR). The USSR sent the Sputnik 1 satellite on October 4, 1957. It weighed about 83 kg (183 lb), and is believed to have orbited around the globe. Analysis of the radio signals was used to gather information about the electron density of the ionosphere , while temperature and pressure data was encoded in

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