Video Transcript
Approximately how long did it take
for the Sun and the planets to form once the cloud of gas and dust they were formed
from started to collapse? (A) Thousands of years, (B) tens of
thousands of years, (C) several million years, (D) several billion years.
This question is asking us how long
scientists estimate our solar system took to form. Our solar system began as a cloud
of dust and gas called a nebula. Gravity caused the cloud to
contract and heat up. And then eventually the Sun and
then the planets were formed. When we consider such a large-scale
phenomenon, we have to realize it didn’t just happen overnight. It would’ve taken a very, very long
time for the solar system to fully form. We can rule out options (A) and (B)
because even tens of thousands of years isn’t long enough.
However, it didn’t take quite as
long as several billion years. The universe itself is around 14
billion years old. As there are lots of solar systems
in the universe, it must take less than several billion years for a solar system to
form. So, we can also rule out option
(D).
From a cloudy, dusty nebula, it
would’ve taken several million years for our planets and star to form the solar
system we know today. Therefore, the answer is (C),
several million years.
