# Are helium, hydrogen, and hot air balloons technically in orbit around the planet, even though they're not actually in space?

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• 4 weeks ago

No, because they aren't in free fall. A falling object is technically in orbit but its path is interrupted by the surface of the planet.

• 4 weeks ago

No, wrong motion to qualify as orbiting.

They are in buoyancy equilibrium.

• Jim
Lv 7
4 weeks ago

No.

Orbits are elliptical motions around a planet following Newton or Einstein's equations.

Balloons and gases simply float.

• D g
Lv 7
1 month ago

A helium balloon has to have enough air pressure below  the balloon to push it up

• 1 month ago

No. An object in orbit is in free fall and has the right horizontal velocity so that its centrifugal force equals the Earth's gravitational force. That is 17,500 miles per hr for low earth orbit.

• 1 month ago

No, because they are within the atmosphere. Which moves with the planet's surface.

• 1 month ago

Not quite. While from a fixed point the balloon would go around the earth as it spins, the balloon is being kept up by buoyancy. For an object to be in orbit, it must stay up by moving fast enough sideways to counteract the acceleration of gravity.

Also, because the balloon is not in orbit, but being held up by a physical force, you would not feel weightless. In a spacecraft, you only feel weightless because you and your spacecraft are moving / falling at the same rate around the planet. Think of it in the same way as how a formation of skydivers appear to be weightless relative to one another, they can only move around because of the atmosphere rushing around them. In space, this would be replaced by maneuvering thrusters.

• 1 month ago

No... an orbit is defined as the curved path of a celestial object or spacecraft around a star, planet, or moon, especially a periodic elliptical revolution.

A balloon wouldn't have periodic revolution, and can't be considered a spacecraft or celestial object.

• jehen
Lv 7
1 month ago

No.  Being in orbit means traveling around the earth at a speed that precisely counteracts the pull of gravity.  That's why something in orbit is weightless, the force of the gravity and the centrifugal force from the orbital speed cancel each other out and the body stays aloft.  Balloons are aloft by way of bouncy - being lighter than air.  But they are not in orbit, and if aboard the baloon there would be no weightlessness to experience.

• Anonymous
1 month ago

No. They are aloft because of their buoyancy. When something is in orbit, it's not because of buoyancy. Instead, it's because it's moving fast enough that the curvature of the Earth is falling away beneath it at the same rate of speed as it is falling into Earth's gravity well.

If you drop a ball. It falls to Earth. If you throw a ball, it also drops to Earth, but it travels some lateral distance before it does. The line of flight is parallel to the ground but because of gravity, the line of flight curves towards Earth until it finally intersects with Earth and the ball lands. So if you threw a ball hard enough that as it moves laterally along that line of flight that's parallel to the ground, the curve of the Earth drops away beneath it at the same speed that gravity is pulling it down, it would be in orbit and never land, if not for friction from air. That's what orbit is, an equilibrium point between moving laterally and downwardly such that an object in motion neither lands nor escapes.