orbit

Pluralorbits

Formsorbits, orbiting, orbited

1. 1
   circling pathnouncountable

   The curved path that an object such as a planet, moon or spacecraft follows around a star, planet or other body, usually repeating in a regular cycle; also, any curving path around a point.

   The space telescope was sent into a wide orbit around a Lagrange point, far beyond the Moon.

   The comet's long, stretched orbit carries it far past Neptune before it swings back toward the Sun.

   UsageSay an orbit around or of something, often with an adjective: a wide orbit, a low orbit.

   Similarpath, course, trajectory

   Note

   Behind the word is Latin orbita, a course or track, even an impression or mark: the Latin named the trail rather than the traveler. In astronomy that trail is usually an ellipse, traced again and again on a regular period, not a perfect circle.

2. 2
   verbtransitive or intransitive

   To move in a circle or curving path around another object or position, as a planet does around a star.

   The space station orbits the planet roughly every ninety minutes.

   Astronomers have found several planets that orbit two stars at once.

   UsageTakes its object directly: orbits the Sun. Orbit around is also common, though the around adds nothing.

   Similarcircle

3. 3
   noununcountable

   The condition of circling another body or point along a curved path.

   After two failed attempts, the company finally got its satellite into orbit.

   The old weather satellite will drop out of orbit and burn up in the atmosphere next year.

   UsageUsually no article: in orbit, into orbit, out of orbit, also in low Earth orbit. A names one particular path: into a stable orbit.

4. 4
   area of activitynounfigurativelycountableusually singular

   The field over which someone or something has influence or control, or within which they are active or interested.

   Several of the senator's former aides remain firmly within her political orbit.

   The once-independent newspaper has slowly drifted into the orbit of a large media group.

   UsageUsually with into, within or out of: fall into the orbit of a stronger state, within her orbit.

   Similarsphere, realm, domain

   Note

   The pull of a larger body is the picture: countries come into the orbit of a stronger state, an aide stays inside a leader's orbit, a reformed railway cannot escape the orbit of government. A daily orbit is gentler, only the round of places someone passes through, like the shop where she buys cigarettes and lottery tickets.

5. 5
   one full tripnouncountable

   A single complete trip around the body that something circles, ending where it began.

   Each orbit of the Sun takes Earth just over 365 days.

   After sixteen orbits, the capsule fired its engines and headed home.

   UsageGoes with numbers and verbs like make and complete: sixteen orbits, one orbit of the Earth.

   Similarrevolution, circuit, lap

6. 6
   eye socketnouncountable

   The bone-walled socket in a vertebrate's skull in which the eyeball sits.

   The CT scan revealed a fracture of the floor of the left orbit.

   Owls have huge eyes, and unlike most birds, their orbits face forward rather than to the sides.

   UsageMostly a medical word, used on scans and in anatomy. In everyday talk people say eye socket.

   Similarsocket

   Note

   The hollow is walled by several skull bones and holds more than the eyeball: the muscles that turn it, fat, nerves and blood vessels. The adjective is orbital, so a break in one of those walls is an orbital fracture.

7. 7
   electron pathnouncountable

   In atomic models such as Bohr's, a definite path along which an electron is pictured as moving around the nucleus.

   Textbook diagrams often show each electron's orbit as a neat circle around the nucleus.

   An electron that absorbs a photon can jump to a higher orbit, then fall back and give off light.

   UsageModern physics uses orbital, the region where an electron is likely to be; orbit belongs to older models, school lessons and popular writing.

   Note

   Electrons got orbits from the early planetary model of the atom, which pictured them as tiny planets on fixed paths. Quantum physics gives an electron no definite path, only a region where it is likely to be found, and calls that region an orbital.

8. 8
   set circlingverbtransitive

   To set a satellite or other object circling a planet, moon or other body, typically by launching it.

   The Soviet Union was the first nation to orbit an artificial satellite, in 1957.

   The startup plans to orbit dozens of small imaging satellites over the next two years.

   UsageThe satellite is the object: a rocket orbits a satellite. Mostly spaceflight writing; everyday speech says put into orbit or launch.

   Similarlaunch

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