HAPPY Spring Equinox!!!

A) How many hours of daylight is there everywhere on Earth when it is the equinox?

B) During the winter solstice how many hours of daylight is there at the North pole?

C) During the winter solstice how many hours of daylight is there at the South pole?

A) 12 hoursB) 0 hoursC) 24 hours

3. One of the consequences of Kepler’s third law is that

a. Jupiter takes longer to orbit the Sun than does the Earth.

b. planets near the Sun take longer to go once around the Sun.

c. to every action there is an equal and opposite reaction.

d. all objects fall at the same rate.

e. the moon’s orbit is inclined with respect to the Earth’s orbit about the Sun.

4. Kepler's law of equal areas says in effect that

a. planets move at a steady pace about the Sun.

b. the more remote planets (whose orbits sweep out larger areas) must orbit faster, to sweep out the whole area in a similar time.

c. planets more slower as they near the Sun.

d. planets move faster as they near the Sun.

5. List 3 of Galileo’s important observations.

• Features on the Moon

• Disk-shaped planets

• Saturn is not round

• Sunspots

• The moons of Jupiter

• The phases of Venus

Who proved Kepler right, mathematically?

Newton

The moon goes through phases becausea. the Earth's shadow falls on different parts

of the moon at different times.b. the moon is somewhat flattened and disk-

like, and appears more or less round depending on the precise angle from which we see it.

c. sunlight reflected from the Earth lights up the full moon but is less effective when the moon is lower in the sky, at which time we see crescents.

d. we see only part of the lit-up face of the moon depending on its position relative to us and the Sun.

The moon goes through phases becausea. the Earth's shadow falls on different parts

of the moon at different times.b. the moon is somewhat flattened and disk-

like, and appears more or less round depending on the precise angle from which we see it.

c. sunlight reflected from the Earth lights up the full moon but is less effective when the moon is lower in the sky, at which time we see crescents.

d. we see only part of the lit-up face of the moon depending on its position relative to us and the Sun.

Waxing Cresent

Waxing Gibbous

T/F We only see one side of the moon.

True

WHY?

What two conditions must be met in order for a solar eclipse to occur?

a. The moon must be full and cross the plane of the Earth’s orbit.

b. The moon must be full and not cross the plane of the Earth’s orbit.

c. The moon must be new and not cross the plane of the Earth’s orbit

d. The moon must be new and cross the plane of the Earth’s orbit.

What two conditions must be met in order for a solar eclipse to occur?

a. The moon must be full and cross the plane of the Earth’s orbit.

b. The moon must be full and not cross the plane of the Earth’s orbit.

c. The moon must be new and not cross the plane of the Earth’s orbit

d. The moon must be new and cross the plane of the Earth’s orbit.

How did Ptolomey account for retrograde motion?

How did Copernicus and how do people now account for retrograde motion?

With what planets will we on Earth see retrograde motion?

Ptolomey used epicycles

Ptolomey used epicycles Planets further away from the sun

then us.

Where is this on Earth? How many hours was the shutter left open?

Near the Pole 12 hours

What if you were at the equator

When is the Earth closest to the sun, summer or winter (for the Northern hemisphere)?

Winter

Explain why our days in the Northern hemisphere are getting longer right now.

Summer Solstice Equinox

Winter Solstice

Put the following scientists in the correct order from oldest to most recent.

Einstein, Copernicus, Tycho Brahe, Ptolomy, Pythagoreus, Newton, Galileo and Kepler

Pythagoreus Ptolomy Copernicus Tycho Brahe Kepler Galileo Newton Einstein

From studying the “wobble” of stars scientists are able to determine the mass of the planet. They know the mass of the star based on its luminosity (brightness). The mass of a B class star is 3.0 x 1031 kg and the mass the planet is 2.0 x 1027 kg. Based on the orbits the gravitational force was calculated to be 9.0 x 1025N. What is the distance from this planet to its star?

2.1 x 1011 m

What is the escape velocity for a rocket launched on Earth? The mass of Earth is 5.98 x 1024 kg and the radius is 6.38 x 106 m.

11,200 m/s

What would a person weigh on Jupiter if she has a mass of 50kg? The mass of Jupiter is 1.9 x 1027kg and the radius is 7.15 x 107m.

1240 N

So what is the acceleration due to gravity on Jupiter?

25 m/s2

What is the difference between fission and fusion?

Fission is when a nucleus splits in two.

Fusion is when nuclei join together

In general…. What type of stars can become

black holes or neutron stars. What type of stars become white

dwarfs.

High mass stars Low mass stars.

1. What does this graph tell astrophyicists?

2. What is the period of orbit for this planet in seconds?

3. What is the mass of this planet? (Ursae Magoris has a mass of 2 X 1030)

That there is a planet orbiting this star.

94,608,000 sec. 2.9 X 1027 kg