orbit
Definition
In physics, an orbit is a curved path that an object follows around another object in space under the influence of gravity. The object that is being orbited is called the central body. The object that is doing the orbiting is called the satellite.
The shape of an orbit is always elliptical. This means that it is like an oval, with one end being closer to the central body than the other. The closer the satellite is to the central body, the faster it travels.
The force of gravity keeps an object in orbit. Gravity is the force that attracts two objects towards each other. The more massive an object is the stronger its gravitational pull. The Sun is very massive, so it has a strong gravitational pull on the Earth. This is why the Earth orbits the Sun.
The speed of an object in orbit is determined by its distance from the central body. The closer the object is to the central body, the faster it travels. This is because the force of gravity is stronger closer to the central body.
The period of an orbit is the time it takes for an object to complete one full orbit around the central body. The period of an orbit is determined by the distance from the central body and the speed of the object. The further away the object is from the central body, the longer the period of the orbit.
How can the word be used?
The speed of an object in orbit depends on its distance from the object it is orbiting.
Different forms of the word
Noun: The path of an object around another object in space.
Verb: To travel around another object in space.
Etymology
The word "orbit" comes from the Latin word "orbita," which means "wheel track" or "rut." The Latin word "orbita" is also the source of the French word "orbite" and the Italian word "orbita.".
The word "orbit" was first used in English in the 16th century. It was used to refer to the path of an object around another object in space.
Question
What might orbit something?
AQA Science Exam Question and Answer
Question:
Explain the concept of an orbit in space and how gravitational forces influence orbital motion. Provide an example to support your explanation.
Answer:
An orbit in space refers to the curved path followed by an object around a celestial body, such as a planet orbiting a star or a moon orbiting a planet. Gravitational forces play a fundamental role in determining the motion of objects in orbit. According to Newton's law of universal gravitation, every object with mass attracts other objects with a force proportional to their masses and inversely proportional to the square of the distance between them.
In the context of orbital motion, this gravitational force acts as a centripetal force, pulling the orbiting object towards the centre of the celestial body it's orbiting. The object's velocity is such that the gravitational force and the centripetal force balance, allowing it to maintain a stable orbit. If the object's velocity is too low, it will fall towards the celestial body, while excessive velocity could cause it to escape the gravitational pull and move away.
For instance, the International Space Station (ISS) orbits Earth due to the gravitational pull between Earth and the ISS. The ISS's speed is carefully controlled to ensure it maintains a stable orbit, neither falling back to Earth nor drifting away. This delicate balance between gravitational attraction and the object's velocity is what keeps objects like the ISS in orbit around a celestial body.