Unit E Section 1.5

Question 1

To locate the position of an object in space, two questions must be answered:

Answer 1

• “How high in the sky is it”?

- “In which direction”?

Question 2

what is the first measurement for tracking things in the sky?

Answer 2

compass direction called the azimuth

Question 3

Different measurements for Azimuth for different directions?

Answer 3

north as 0° and going clockwise, the azimuth will tell you which direction to point

180° from 0° would have you pointing due south

270° would have you pointing west

Question 4

What is the second measurement?

Answer 4

shows how high the object is in the sky.

altitude

Question 5

Where does altitude range from?

Answer 5

The altitude ranges from 0 at the horizon to 90° straight up.

Question 6

What is Zenith?

Answer 6

Zenith refers to the highest point directly overhead.

Question 7

How is the motion of stars seen from Earth?

Answer 7

• Because they are at such enormous distances from Earth, the stars appear to stay in one place in the sky
• Only when viewed over extremely long periods of time can some stars be seen to move very slightly

Question 8

How is planetary motion seen from Earth?

Answer 8

a person needs to wait only a few days or weeks to see a planet change its position against the background of stars

Sometimes the planets seemed to speed up over time in their movements across the sky.

Other times they appeared to standstill

Question 9

What word does the word planet come from?

Answer 9

“Planet” comes from the ancient Greek word for

“wanderer.”

Question 10

What is ecliptic?

Answer 10

a great circle on the celestial sphere representing the sun’s apparent path during the year, so-called because lunar and solar eclipses can occur only when the moon crosses it.

Question 11

What is a celestial sphere?

Answer 11

The celestial sphere is the name given to the very large imaginary “sphere of the sky” surrounding Earth

Question 12

What is a celestial equator?

Answer 12

The celestial equator is the imaginary line around that sphere of sky directly above Earth’s equator

Question 13

What position of the Earth makes the solstice and equinox occur?

Answer 13

The ecliptic—the apparent path of the Sun through the sky during the year—crosses the celestial equator at the vernal (spring) and autumnal (fall) equinoxes.

The Sun’s most northerly position on the ecliptic marks the summer solstice. Its most southerly position marks the winter solstice.