Space Objects & the Chelyabinsk Event
Gravity & Forces
Orbits & Motion
Ellipses & Collisions
Energy in Orbit & Orbital Changes
100

A rock from space that is still traveling through Earth's atmosphere is called this.

What is a meteor?

100

This law gives us the equation Fg = G(m₁m₂)/d².

What is Newton's Law of Universal Gravitation?

100

The time it takes an object to complete one full orbit.

What is the period?

100

The shape of all planetary orbits.

What is an ellipse?

100

In an elliptical orbit, an object moves fastest at this point.

What is perihelion?

200

A rock from space that has landed on Earth's surface is called this.

What is a meteorite?

200

In the gravitation equation, increasing this variable causes gravitational force to increase.

What is mass?

200

For a stable orbit, an object must have exactly the right amount of this — too little and it falls in, too much and it escapes.

What is velocity?

200

The Sun's location within a planetary orbit.

What is a focus?

200

As an orbiting object moves away from the Sun and slows down, kinetic energy is transferred into this.

What is the gravitational field?

300

The Chelyabinsk meteor came from this region of the solar system before being redirected toward Earth.

What is the asteroid belt?

300

In the gravitation equation, increasing this variable causes gravitational force to decrease.

What is distance?

300

Compared to planets close to the Sun, planets farther away orbit at this relative speed.

What is slower?

300

The longest radius of an ellipse, used to describe orbit size.

What is the semimajor axis?

300

Energy is conserved in an orbital system. This means the total energy can never be this.

What is created or destroyed?

400

When the Chelyabinsk meteor entered the atmosphere, it broke apart and released energy. Name two forms that energy took.

What are light, heat, and sound? (any two)

400

If the distance between two objects doubles, the gravitational force becomes this fraction of its original value.

What is one-fourth?

400

Kepler's Third Law states that T²/a³ has this value for all objects orbiting the same body.

What is constant?

400

An eccentricity of 0.95 describes an orbit that is this shape compared to one with eccentricity of 0.01.

What is more elongated?

400

Our two-body orbit models failed to predict the Chelyabinsk meteor's original orbit. This is because real orbital systems contain this.

What is more than two bodies?

500

Scientists believe the Chelyabinsk meteor's orbit was changed by two types of interactions. One was a collision — what was the other?

What is gravitational perturbation?

500

The gravitational force Earth exerts on the Moon and the force the Moon exerts on Earth are related in this way.

What is equal?

500

An object orbiting far from the Sun has a longer period than one orbiting close in. This is because the gravitational force acting on it is this.

What is weaker?

500

Two objects whose orbits cross are not guaranteed to collide. This is the missing condition they also need.

What is being at the same location at the same time?

500

A small spacecraft hovering near an asteroid can slowly change the asteroid's orbit using only this force — no collision needed.

What is gravity?

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