How do scientists estimate how old the solar system is?
A) They measure the speeds and distances of galaxies, and calculate the time it took for them to travel that distance.
B) They make a guess: no one really knows how old the solar system is.
C) They look up the answer in a book.
D) They measure how fast the Sun is losing energy, and how much energy it has to lose.
E) They measure the abundances of radioactive elements in meteorites, and use their half-lives to calculate the age.
Question 2
What would be the consequence(s) of more frequent collisions between planets and asteroids?
A) Earth and other planets would have more large craters.
B) We would observe more meteor showers.
C) We would find more Martian meteorites on Earth.
D) A and B
E) A and C
Divisions of the nervous system
The respiratory system
Conducting system of the heart.
What Happens to Incoming Solar Radiation?
Muscular system
Complement System