Space science focuses on problems such as what the universe (including our own solar system) is made of, and how old everything is in space. It also looks closer to home—for example, studying how the moon affects Earth as it revolves around us (think: tides and eclipses).
The following practice questions may look intimidating, but if you stay calm and concentrate on what they're really asking, you should find the answers in no time.
Practice questionsThe first question refers to the following passage based on information on the NASA website.
The seasons on Earth are caused by the tilt of the Earth as it rotates on its axis and revolves around the Sun. The 23.5 degree tilt of the Earth's axis results in changes of the angle of incident sunlight. A common misconception is that the seasons are caused by the distance between the Earth and Sun. In fact, summer in the Northern Hemisphere occurs at aphelion, the farthest distance between the Earth and Sun, and follows summer solstice when incident sunlight is most concentrated along the Tropic of Cancer, 23 degrees 26 minutes 22 seconds.
- The point at which the Earth and Sun are farthest apart is called the
A. solstice B. aphelion C. axis D. Tropic of Cancer
The second question refers to the following table, which is adapted from Hands-On General Science Activities with Real-Life Applications, by Pam Walker and Elaine Wood (John Wiley & Sons, Inc.).
- If you were an aeronautical engineer planning a journey to Mars, why would you prefer to go to a space station on the moon and then launch the rocket to Mars instead of going directly from Earth to Mars?
A. Lower gravity on the moon means you need less fuel for the launch. B. You have more space to take off and land on the moon. C. No atmosphere means an easier takeoff. D. The moon is closer to Earth than Mars.
Answers and explanations
- The correct answer is Choice (B).
The passage states, "summer in the Northern Hemisphere occurs at aphelion, the farthest distance between the Earth and Sun … " This question requires you to find a detail in a dense passage, so practice close reading, which is careful and thorough reading of a text.
- The correct answer is Choice (A).
Lower gravity on the moon means you need less fuel for the launch. The less fuel you need to launch, the less you have to carry. The gravity on the moon is less than that on Earth, so you need less force and less fuel to break free of gravity.