Gravitational Force
This invisible force pulls objects toward each other and keeps us grounded on Earth.
What is gravity?
This force keeps an object moving in a circle and always points toward the center of the circle.
What is centripetal force?
This massive object at the center of our solar system exerts the strongest gravitational pull.
What is the Sun?
Comets are often called "dirty snowballs" because they are made of this combination of materials.
What are ice, dust, and rock?
Our solar system formed about this many billion years ago from a giant cloud of gas and dust.
What is 4.6 billion years ago?
This famous scientist developed the Universal Law of Gravitation.
Who is Issac Newton?
This property of an object resists changes in its motion and causes it to move in a straight line unless acted on by a force.
What is inertia?
Planets stay in orbit around the Sun due to the balance between their forward motion and this force.
What is gravitational pull?
This part of a comet becomes visible as it gets close to the Sun and begins to heat up.
What is the tail?
This force caused the gas and dust in the solar nebula to collapse and form the Sun at the center.
What is gravity?
The gravitational force between two objects depends on their mass and this other factor.
What is the distance between them?
This planet’s gravity provides the centripetal force that keeps the Moon in orbit.
What is Earth?
This planet has the strongest gravitational force of all the planets in the solar system.
What is Jupiter?
The path that a comet travels around the Sun is usually shaped like this.
What is an ellipse or elliptical?
This process caused heavier elements to sink to the center of forming planets, creating layers like the core and crust.
What is differentiation?
This term describes the force that pulls all objects toward the center of the Earth, and it's why dropped objects fall.
What is weight?
This happens to the direction of an object’s velocity in circular motion, even if its speed stays the same.
What is it constantly changes?
Gravity is responsible for this natural motion of Earth that gives us a year.
What is Earth’s revolution around the Sun?
Most comets come from one of these two distant regions of our solar system: the Kuiper Belt or this cloud.
What is the Oort Cloud?)
These small rocky bodies were the building blocks of the planets during the early solar system.
What are planetesimals?
This is why the moon orbits the Earth instead of floating away into space.
What is Earth's gravitational pull?
When you swing a ball on a string in a circle, this object is providing the centripetal force.
What is the string?
These icy objects from the outer solar system follow long, elliptical orbits due to the Sun’s gravity.
What are comets?
A comet’s tail always points in this direction, regardless of its travel path.
What is away from the Sun?
Scientists believe a Mars-sized object collided with early Earth, leading to the formation of this.
What is the Moon?