It is the so-called swept area per unit time that remains constant in an eliptical orbit. Picture a planet in an eliptical orbit around the sun. Draw a line from the sun to the location of the planet at any given instant of time. Draw another line from the sun to the location of the planet at, say, one week later. The two segments drawn and the path of the orbit make a geometric figure. It's like a "slice" of the elipse of the planet's orbit, and it has a given area. Got it? Pick another spot in the orbit of the planet and draw a line to it. Then draw another line to where it is one week later. Again, the two segments and the curve of the planet's orbit form a geometric "slice" of the elipse. Any "slices" (and there are an infinite number of geometric possibilities) of the elipse created by the week of elapsed time will have an equal swept area as described by the line segments drawn from the sun to the location of the planet at the beginning and end of that week. The last bit of information needed to tie this together is that the planet is moving more slowly when it is farther from the sun than it is when it's closer. The segments drawn to create the "one-week slice" when the planet is farther out will be longer, but the slower movement of the planet will make the "slice" a bit "narrower" than the one-week slice of the planet when it's closer in. Pick any starting point in an orbit and draw a segment. Pick any length of time, be it an hour, day, week, month, or whatever, and draw another segment. Using that same length of time, draw more segments and create more "slices" of the elipitical pie. They'll all have the same swept area.
Plants remain in orbit around the sun, like all other objects in the solar system, due to the gravitational force exerted by the sun. This force keeps them moving in a circular or elliptical path around the sun. The balance between the gravitational force of the sun and the plants' inertia keeps them in orbit.
Comets typically have elliptical orbits, which means their paths around the Sun are elongated and not perfectly circular. This is due to the gravitational influence of other celestial bodies, causing their orbits to be more elongated.
When dealing with the distances and times you are referencing they will eventually go back together. The time is in billions of years.The whole idea of expansion and shrinkage of the universe is in play here.
No, it is not. NO orbits of natural satellites are perfect circles. (And when NASA manages to achieve a perfectly circular orbit for an artificial satellite, it doesn't stay that way for very long!) All orbits are ellipses. The Earth's orbit is pretty close to circular; it's only about a 3% eccentricity. On January 4th (or thereabouts) when Earth is closest to the Sun, it's about 91 million miles away; on July 2nd (or about) when the Earth is most distant, it's a little over 94 million miles.
All the planets orbit in a perfect circle, so they always stay the same distance from the sun, except Pluto, which is why it is now a "Dwarf Planet".
Radial force in circular motion does not work because the acceleration needed to keep an object moving in a circle is provided by the centripetal force, directed towards the center of the circle. This centripetal force maintains the object's velocity and prevents it from moving in a straight line. Therefore, no additional radial force is required for the object to stay in orbit.
The planets orbit because of gravity and their momentum. They are constantly flying away from the sun, but at the same time are being pulled toward it by gravity. The end result is that they stay moving in a circular motion around the sun.
It means that an object remains in a stable orbit around a central object. For example the Earth stays in a stable near-circular orbit around the Sun although it is continuously moving at around 18 miles per second in a direction that is along the ecliptic and at right angles (approximately) to the direction of the Sun.
The "inertia" of the moving planet combines with the force of gravity between the planet and the Sun, causing the planet to move in an orbit around the Sun. "Inertia" is basically the tendency for a moving body to move in a straight line unless acted upon by a force (such as gravity).
Plants remain in orbit around the sun, like all other objects in the solar system, due to the gravitational force exerted by the sun. This force keeps them moving in a circular or elliptical path around the sun. The balance between the gravitational force of the sun and the plants' inertia keeps them in orbit.
The circular orbit velocity formula is v (GM/r), where v is the velocity, G is the gravitational constant, M is the mass of the central object, and r is the distance from the center. This formula is used in physics to calculate the velocity required for an object to stay in a circular orbit around a central mass, such as a planet or a star. It helps scientists understand the dynamics of celestial bodies and spacecraft in orbit.
Satellites stay in orbit due to a balance between their forward motion, which keeps them moving forward, and the gravitational pull of the Earth, which pulls them inward. This balance creates a circular path around the Earth called an orbit. If a satellite were to lose its forward motion or if the gravitational pull were to increase, it would fall back to Earth.
All natural orbits are ellipses. We can force an artificial satellite into a spherical orbit, but it won't STAY there without occasional adjustments. The "primary body" - in this case, the Sun - is at one of the two focuses (foci) of the orbit. If the focus is very close to the "center" of the ellipse, then the eccentricity of the orbit (how much it varies from a perfect circle) is close to zero.
A comet will stay in space until its orbit brings its withing the gravity well of another body.
Stay in orbit
That means that it is moving - that it doesn't stay in the same place.
Astronauts and satellites stay in orbit because they are moving fast enough horizontally that the force of gravity pulling them towards Earth is balanced by their forward momentum. This creates a state of continuous free fall around the planet, resulting in a stable orbit.