1. Unit E – Space Exploration
Lesson 4-3: (Sec 1.4 and 1.5)
Our Solar Neighbourhood and
Describing the Position of Objects in Space

2. A. Protoplanet Hypothesis
model for explaining the
birth of solar systems: 1.
cloud of gas and dust begins swirling 2.
>90% of material gathers in centre, forming sun 3.
remaining material clumps together into planets and moons

3. B. The Sun surface temperature = 5500C core temperature =
15,000,000C (15 million degrees)
emitted by sun are called
charged particles
solar wind
Earth is protected from by its
solar wind
magnetic field

4. C. The Planets inner “terrestrial” planets are smaller and rockier
Mercury
Venus
Earth
Mars

5. outer “Jovian” planets are large and gaseous
Jupiter
Saturn
Uranus
Neptune

6. was the
Pluto
farthest planet until 2003
there is now a
tenth planet with its own moon

7. D. Asteroids and Comets
asteroids are between a few metres and a few hundred metres in size
found in the asteroid belt between Mars and Jupiter
Gaspra

8. comets are made of dust, rock and ice and move around the sun in elliptical paths
when comets come close to the sun, gases are released by the heat, forming very long tails (millions of km)
Halley’s
Comet
Hale-Bopp
Comet
Shoemaker-Levy Comet

9. E. Meteoroids, Meteors, Meteorites
meteoroids are pieces of rock floating through space
meteors are meteoroids that get pulled into the atmosphere…they glow brightly because of the heat of friction

10. meteorites are meteors that have hit the Earth’s surface

11. Describing the Position of Objects in Space
1.5
Describing the Position of Objects in Space

12. A. Positions of Objects
to locate an object in space, two measurements need to be taken: 1.
azimuth –
compass direction in degrees from North
eg) 0 = North, 180 = South 2.
altitude –
how high up in the sky
eg) 0 = horizon, 90 = straight up
an is called the
altitude of 90
zenith

13. zenith

14. B. Motion of Objects other stars appear to be
motionless…they move only slightly over long periods of time
planets change positions
in very short periods of time
the through the sky is called the
path the sun follows
during the year
ecliptic

16. Assignment
Worksheet 4