SPACE

1. Space Basics

   1. What is the astronomical basis for a year? Month? Week? Day? 

A day is the amount of time it takes the Earth to spin once on its axis (24 hours). A month is based on the length of time it takes the moon to orbit the Earth once (about 29.5 days). A week does not have an astronomical basis, and comes from the Torah. 

2. What is the reason for having a leap year? How about a Jewish leap year?

A year is really 365.25 days, so every four years we add an extra day to make up for the lost quarter-days. A Jewish leap year adds an extra month 7 times in 19 years to synchronize the lunar and solar calendars (since the Jewish calendar follows lunar months). 

3. What is gravity?

It is one of the four fundamental forces and is a force of attraction between large bodies. 

4. How do we know that the Earth is round? Give at least 3 pieces of evidence.

1. Ships disappear bottom-first over the horizon.

2. Changing star patterns as you travel from the northern to the southern hemisphere. 

3. Earth’s curved/circular shadow on the moon.

5. What is a light year? How is it different from an astronomical unit (AU)?

A light year is the distance that light travels in one year. The speed of light is 300,000 km/s, so a light year is roughly 9.5 trillion kilometers! An astronomical unit is the average distance between the Earth and the sun. It is equal to 150,000,000 kilometers.

6. What is a constellation? How many are there? Give an example. 

A constellation is a pattern of stars in the night sky. There are 88 total constellations (12 of these make up the zodiac). An example is ursa major or libra. 

7. What is the “north star”? Why is it useful? 

The north star (officially named Polaris) is a star that is directly aligned with the north pole so it appears to not move in the night sky. You can use it to find North. 

2. Earth and Solar System

   1. What causes Earth’s seasons? 

Earth’s 23.5° tilt is the cause of the seasons. When the Northern Hemisphere tilts towards the sun, it receives more heat and sunlight, causing summer. When the Southern Hemisphere is tilted towards the sun, it is summer in the South and winter in the North. 

2. What causes the tides? 

The tides are caused by the moon’s gravity pulling on the Earth’s bodies of water. The sun’s gravity also has an effect on Earth’s tides! 

3. What is an eclipse? What is the difference between a lunar and solar one? 

A lunar eclipse is when Earth gets between the sun and moon, blocking the sun’s light from hitting the moon and making the moon appear dark. A solar eclipse is when the moon gets between the Earth and the sun, blocking the sun’s light from hitting the Earth, and making the sun appear dark. 

4. What are the 8 planets of the solar system? Which planets are “inner” and which are “outer”? Which planets are gaseous and which are terrestrial? 

Inner/terrestrial planets: Mercury, Venus, Earth and Mars  

Outer/gaseous planets: Jupiter, Saturn, Uranus and Neptune

5. What is a dwarf planet? Give an example. 

A planet that is smaller and has not “cleared its orbit”. Pluto is an example.

6. What is the difference between the Kuiper Belt and the Oort Cloud? 

Kuiper Belt refers to the region of the Solar System beyond Neptune. It contains dwarf planets, comets, and dust. The Oort Cloud is the outer limit of the Solar System. It is believed to be composed mostly of ice comets. 

7. State two differences between comets and asteroids. 

Comets are chunks of dust, ice and rock coming from the outer reaches of the Solar System. They have an eccentric orbit around the sun. Comets have a tail (atmosphere). Asteroids are rocky pieces of space debris orbiting the sun. They do not have tails. Most are in the Asteroid Belt between Mars and Jupiter.

8. What is the difference between a meteoroid, meteor, and meteorite? 

A meteoroid is a relatively small space rock that broke off from some other celestial object. A meteor is a meteoroid that burns up in Earth’s atmosphere. A meteorite is one that is large enough to survive the trip through the atmosphere and land on Earth. 

9. What is the sun primarily made up of and how does it work?

The sun is made mostly of hydrogen gas and works through the nuclear fusion of hydrogen atoms into helium atoms. 

10. What is the aurora borealis? 

Also known as the Northern Lights, it is a result of charged solar particles colliding with the Earth and being attracted to the magnetic poles.  

11. What are three things that can happen to a star at the end of its life cycle?

Supernova (explode into a nebula of dust and gas), white dwarf (cooling off slowly), or black hole (so large that it implodes). 

3. Exploring Space 

   1. What was the name of the first satellite? When was it launched?

Sputnik, launched in 1957

2. Who was the first person in space? Who was the first person on the moon? 

Yuri Gagarin was the first person in space and Neil Armstrong was the first person on the moon.

3. What is Canada’s major contribution to the International Space Station? 

The Canadarm (a crane-like mechanical arm)

4. How might humans make Mars habitable for human life? What is this process called?

Through the process of terraformation. This is when a planet is slowly made habitable over many decades or even centuries. In the case of Mars, it would have to be warmed up (probably by introducing or releasing its greenhouse gases), water and lifeforms added - starting with microbes and progressing to bigger and bigger organisms. 

5. How wide is the observable universe? 

About 93 billion light years. 

6. Only 4% of the universe is made up of visible matter. What is the rest made up of? 

The rest is made up of dark matter and dark energy.