Vocabulary Challenge
This verb means to strike or bump into one another with force, much like the material that formed our sun.
What is collide?
According to the 2006 definition, a planet must orbit around this specific body in our solar system.
What is the sun?
Before they were solid objects, the sun and planets were all part of a big cloud of these two things.
What are gas and dust?
This is the specific name given to planets found circling stars outside of our own solar system.
What are exoplanets?
This is the primary reason why scientists sometimes argue over whether a gassy object is a "tiny star" or a "big planet".
What is how it was formed (from a cloud or around a star)?
In science, this noun refers to an amount of something that has no particular form, such as a "mass of stuff".
What is mass?
To be a planet, an object must be big enough for gravity to force it into this specific shape.
What is a sphere (or spherical)?
This force is responsible for collecting material in the center of a cloud to create a star.
What is gravity?
This type of "star" forms from a gas cloud but isn't big enough to give off light or make lots of energy.
What is a brown dwarf?
True or False: Scientists have found an object that is redder and younger than most brown dwarfs.
What is True?
This term describes a new thing being created or coming together, like a friendship or a planet.
What is form?
A planet must have enough gravity to have "cleared away" these from near its orbit.
What are any other objects of a similar size?
This is the name of the "cosmic cloud" mentioned in the text where stars and planets form.
What is Sharpless 2-106?
Some scientists believe an object is only a planet if it formed around one of these.
What is a star?
Some scientists argue that a gassy object can only be called a planet if it was created in this specific location.
What is around a star?
When gravity makes one object come toward another, it is said to do this.
What is attract?
This is the year scientists finally agreed upon a formal definition for what a planet actually is.
What is 2006?
Planets in our solar system formed from this type of material that swirled around the forming sun.
What is [leftover] stuff?
Of the planets mentioned in the text, this one is described specifically as a "big sphere of gas".
What is Jupiter?
This is the alternative theory for how a "planet" might end up in the middle of nowhere if it didn't form there originally.
What is it got flung off into space?
If a choir decides to "sing together," they are using this vocabulary word to describe how they started their group.
What is form?
The 2006 definition is currently limited because it is mostly focused on the planets found inside this specific area.
What is our own solar system?
While the sun was forming, this was happening to the "leftover stuff" as it swirled around the center.
What is colliding and collecting together?
Although they are big compared to most planets, brown dwarfs are not big enough to produce these two things like a "bright star" does.
What are energy and light?
According to the text, if a gassy object just forms from a cloud of gas without a star, some scientists label it as this instead of a planet.
What is a not-quite-star?