Grade 9 Science - Unit E (Space Exploration)

Which model of planetary motion has the planet earth as being in the center the center of the universe?

Geocentric model.

Who came up with the geocentric model of planetary motion.

Aristotle.

Which planetary motion model suggested that the sun was at the center and the planets (including earth) along with their moons, circled around it?

Heliocentric model.

An azimuth of 180 degrees would put the object in the:

South.

The average distance from Earth to the Sun is about 150 000 000 km. Astronomers refer to this distance as what kind of other unit?

Astronomical unit.

Two planets with orbits closer to the Sun than Earth are

Mercury and Venus.

One of the measurements used to locate objects in the sky is compass direction. The compass direction measured clockwise from north is called

Azimuth.

The height of an object above the horizon is referred to as its

Altitude.

When an object in the sky has reached its highest point overhead, we say it has reached its

Zenith.

In the northern hemisphere, the longest day of the year is June 21. It is known as the summer

Solstice.

A grouping of stars in the night sky which form an apparent pattern is called a

Constellation.

The ____________________ model of the solar system places the Sun at the center of the orbiting planets.

Heliocentric.

A example of a natural satellite is...

Asteroids revolving around the sun.

Objects designed and built by humans to orbit Earth are called

Satellites.

What sort of waves exhibit the Doppler effect?

Light, water and sound waves.

The shift in position that "seems" to occur when observing the same object from a different perspective/position is called

Parallax or triangulation

A blue shifted star is headed ____________the earth.

Towards.

A red shifted star is heading ____________ from the earth.

Away.

Parallax

The apparent movement of closer objects due to the viewer's change in position.

When astronomers use a spectroscope, the resulting spectra have black lines present. These black lines indicate the

Elements in the star.

If a star's spectra are shifted to the red end of the spectrum, this means the star is moving

Away from Earth.

The technique for measuring distances based on the geometry of a triangle is called

Triangulation.

There is a difference between the sound of a siren of an emergency vehicle as it approaches you and the sound of the siren when the vehicle is moving away from you. This change in pitch is referred to as

Doppler shift

"Space junk" is

Any debris which falls off spacecraft and dead satellites.