Video Transcript
Which of the following shows what
the solar system was before it began to form?
This question asks us to select the
picture that best represents scientists’ model of what the solar system looked like
before it began to form.
First, let’s look at option (A): a
large cloud of gas and dust in space. Scientists think that the solar
system formed from a large cloud of dust and gas called a nebula. The theory states that gravity
pulled the dust and gas particles in the cloud closer together so that the entire
cloud contracted, or got smaller. From there, the cloud heated
up. After that, objects slowly began to
form, including our Sun and then the planets around it.
By contrast, let’s look at option
(B): a large number of asteroids in space. The asteroids in our solar system
were probably formed alongside the planets after the cloud of dust and gas had
contracted. Today, there are a large number of
asteroids between Jupiter and Mars. One theory states that Jupiter was
so big that it prevented any other planets being formed between Mars and Jupiter, so
the dust and gas that settled there eventually formed rocklike formations we call
asteroids. This means that these asteroids
couldn’t have been around before the solar system began to form. So option (B) cannot be the correct
answer.
Therefore, we can conclude that the
correct answer is (A), a large cloud of dust and gas in space.
