A heliocentric orbit (also called circumsolar orbit) is an

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

around the

barycenter In astronomy, the barycenter (or barycentre; ) is the center of mass of two or more bodies that orbit one another and is the point about which the bodies orbit. A barycenter is a dynamical point, not a physical object. It is an important con ...

of the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Sola ...

, which is usually located within or very near the surface of the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

. All

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

comet A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...

s, and

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

s in the Solar System, and the Sun itself are in such orbits, as are many artificial probes and pieces of

debris Debris (, ) is rubble, wreckage, ruins, litter and discarded waste, garbage/refuse/trash, scattered remains of something destroyed, or, as in geology, large rock fragments left by a melting glacier, etc. Depending on context, ''debris'' can ref ...

. The moons of planets in the Solar System, by contrast, are not in heliocentric orbits, as they orbit their respective planet (although the Moon has a convex orbit around the Sun). The barycenter of the Solar System, while always very near the Sun, moves through space as time passes, depending on where other large bodies in the Solar System, such as

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...

and other large

gas planet A gas giant is a giant planet composed mainly of hydrogen and helium. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" was originally synonymous with "giant planet". However, in the 1990s, it became known that Uranu ...

s, are located at that time. A similar phenomenon allows the detection of

exoplanets An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detec ...

by way of the radial-velocity method. The ''helio-'' prefix is derived from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

word "ἥλιος", meaning "Sun", and also

Helios In ancient Greek religion and Greek mythology, mythology, Helios (; ; Homeric Greek: ) is the god who personification, personifies the Sun. His name is also Latinized as Helius, and he is often given the epithets Hyperion ("the one above") an ...

, the

personification Personification is the representation of a thing or abstraction as a person, often as an embodiment or incarnation. In the arts, many things are commonly personified, including: places, especially cities, National personification, countries, an ...

of the Sun in

Greek mythology Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories conc ...

. The first spacecraft to be put in a heliocentric orbit was

Luna 1 ''Luna 1'', also known as ''Mechta'' ( , ''Literal translation, lit.'': ''Dream''), ''E-1 No.4'' and ''First Lunar Rover'', was the first spacecraft to reach the vicinity of Earth's Moon, the first spacecraft to leave Earth's orbit, and the fi ...

in 1959. An incorrectly timed upper-stage burn caused it to miss its planned impact on the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

Trans-Mars injection

A ''trans-Mars injection (TMI)'' is a heliocentric orbit in which a propulsive maneuver is used to set a

spacecraft A spacecraft is a vehicle that is designed spaceflight, to fly and operate in outer space. Spacecraft are used for a variety of purposes, including Telecommunications, communications, Earth observation satellite, Earth observation, Weather s ...

on a

trajectory A trajectory or flight path is the path that an object with mass in motion follows through space as a function of time. In classical mechanics, a trajectory is defined by Hamiltonian mechanics via canonical coordinates; hence, a complete tra ...

, also known as Mars transfer orbit, which will place it as far as

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

orbit. Every two years,

low-energy transfer A low-energy transfer, or low-energy trajectory, is a route in space that allows spacecraft to change orbits using significantly less fuel than traditional transfers. These routes work in the Earth–Moon system and also in other systems, such as ...

windows open up, which allow movement between the two planets with the lowest possible

energy Energy () is the physical quantity, quantitative physical property, property that is transferred to a physical body, body or to a physical system, recognizable in the performance of Work (thermodynamics), work and in the form of heat and l ...

requirements. Transfer injections can place spacecraft into either a

Hohmann transfer orbit In astronautics, the Hohmann transfer orbit () is an orbital maneuver used to transfer a spacecraft between two orbits of different altitudes around a central body. For example, a Hohmann transfer could be used to raise a satellite's orbit fro ...

bi-elliptic transfer In astronautics and aerospace engineering, the bi-elliptic transfer is an orbital maneuver that moves a spacecraft from one orbit to another and may, in certain situations, require less delta-v than a Hohmann transfer maneuver. The bi-ellip ...

orbit. Trans-Mars injections can be either a single maneuver burn, such as that used by the

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

MAVEN MAVEN is a NASA spacecraft orbiting Mars to study the loss of that planet's atmospheric gases to space, providing insight into the history of the planet's climate and water. The name is an acronym for "Mars Atmosphere and Volatile Evolution" w ...

orbiter in 2013, or a series of perigee kicks, such as that used by the

ISRO The Indian Space Research Organisation (ISRO ) is India's national space agency, headquartered in Bengaluru, Karnataka. It serves as the principal research and development arm of the Department of Space (DoS), overseen by the Prime Minister o ...

Mars Orbiter Mission Mars Orbiter Mission (MOM), unofficially known as ''Mangalyaan'' (Sanskrit: 'Mars', 'Craft, Vehicle'), is a space probe orbiting Mars since 24 September 2014. It was launched on 5 November 2013 by the Indian Space Research Organisation (ISRO ...

in 2013.Orbiter successfully placed in Mars Transfer Trajectory

References

{{Portal bar, Physics, Astronomy, Stars, Spaceflight, Outer space, Solar System, Science Orbits Astrodynamics Spacecraft propulsion Orbital maneuvers Exploration of Mars

Trans-Mars injection

See also

References