Life Cycle of Stars
What is a nebula?
A cloud of gas and dust where stars form.
What is a galaxy?
A collection of stars, gas and dust held by gravity.
What shape is a planet orbit?
Ellipse
What force keeps planets in orbit?
Gravity
What causes day and night ?
Earth rotation
What stage is the Sun currently in?
Main Sequence
What evidence supports Big Bang?
MB radiation
What does eccentricity measure?
How stretched an orbit is
Difference between terrestrial and Jovian planets?
Rocky inner vs gas giant outer planets.
What causes seasons?
Earth tilt and revolution
What event marks the explosive death of a massive star?
A Supernova
What does redshift tell scientists?
Universe is expanding; galaxies move away.
Where is Sun in ellipse?
At one focus
What is Kepler First Law?
Planets orbit in ellipses with Sun at one focus.
What happens during a solar eclipse?
Moon blocks Sun from Earth
What can remain after a supernova?
A neutron star or black hole
Why are galaxies important?
They help explain structure and expansion.
When does planet move fastest?
At perihelion
Why move faster closer to Sun?
Kepler 2nd Law.
Difference between rotation and revolution?
Rotation spins; revolution orbits.
A planet is shown at two locations in its orbit: Point A near perihelion and Point B near aphelion. At which point does the planet have the greatest kinetic energy, and how do Kepler's Laws explain this?
Point A (perihelion). The planet moves fastest when closest to the Sun because gravity is strongest there. Kepler's Second Law states that a planet sweeps out equal areas in equal times, requiring it to move faster near perihelion and slower near aphelion.
+ 100 extra points
What is the name of the point in a planet's orbit where it is closest to the Sun?
Perihelion
Which scientist developed the three laws of planetary motion that describe how planets orbit the Sun?
Whole name
Johannes Kepler
+50 points
A planet orbits the Sun in an elliptical path. According to Kepler's Second Law, if the planet is at perihelion and another identical planet is at aphelion, which planet has the greater orbital velocity and why?
The planet at perihelion has the greater orbital velocity because it is closer to the Sun and experiences a stronger gravitational pull. Kepler's Second Law states that planets sweep out equal areas in equal times, so they must move faster when closer to the Sun and slower when farther away.
Draw or identify the positions of the Sun, Earth, and Moon that would create a total lunar eclipse. Explain why the eclipse occurs.
Sun → Earth → Moon (Earth is between the Sun and Moon).
A total lunar eclipse occurs when Earth's shadow falls completely on the Moon, blocking direct sunlight from reaching it.