Astronomy Flashcards
What causes the seasons?
Earth’s tilted axis.
The Earth’s tilt is 23.5 degrees. When the Northern Hemisphere is angled toward the sun, it is summer, hence the Southern hemisphere is angled away from the sun causing winter. Similarly, when the Northern hemisphere is tilted away from the sun, it is winter. Thus, the Southern hempishere has winter.
What does Earth’s rotation cause?
Day and night cycle.
How long is a day on Earth?
24 hours
How long is the Earth’s rotation around the Sun?
365.25 days
What causes tides?
The moon’s gravitational pull.
The moon’s gravitational pull generates tidal force which causes the Earth’s ocean water to rise on the side closest to the moon and the side farthest from the moon.
What is a solar eclipse?
An eclipse where the Sun is blocked by the moon, causing complete darkness.
Partial: Moon passes between Sun and Earth, but not in a exactly straight line. Only a part of the Sun will appear covered.
Total: Sun, Earth, and moon in an exactly straight line, covering the entire Sun.
Annular: The moon does not appear large enough to cover the entire Sun, leaving a thin rim around the moon.
What phase is the moon during a solar eclipse?
New moon
What is a lunar eclipse?
An eclipse where the moon is blocked by the Earth, causing a darkened moon.
Partial:
Total: When the moon moves completely behind Earth.
Prenumbral:
What phase is the moon during a lunar eclipse?
Full moon
What keeps moons and planets in orbit?
The Sun’s gravity pulls the planets in orbit around it.
What do the inner planets have in common?
All of the inner planets are solid, dense and rocky planets (terrestrial). None of the inner planets have rings.
Why are Venus and Earth alike?
Earth and Venus are similar in size, mass, density, and volume. Both planets formed around the same time.
What keeps the atmosphere around planets?
Gravitational force generated by the planet itself. Gravity pulls gas molecules in the atmosphere toward the planet’s surface.
What is unique about Uranus?
Uranus is the only planet whose equator is almost at a right angle to its orbit. It has a tilt of 97.77 degrees, which causes the most extreme seasons in the solar system.
How are dwarf planets different from classical planets?
Dwarf planets don’t have enough gravitational force needed to pull in all of the material found in their orbits.
What will our Sun become at the end of its life? What type of star is the Sun? How does it produce energy?
The Sun will turn will turn into a white dwarf at the end of its life. The Sun is a yellow dwarf star. It produces energy by nuclear fusion.
What is nuclear fusion?
A process where two atomic nuclei combine to form a heavier nucleus while releasing a large amount of energy.
What is a solar prominence?
Solar prominences are large, circular structures on the edge of the solar disk. Prominences are huge, stretching out for thousands of kilometers.
What is a solar flare?
A solar flare is a massive explosion on the sun. A solar flare happens when energy stored in the Sun’s magnetic field is quickly released. When a solar flare happens, a burst of radiation is produced, causing a sudden intense brightening of a region on the Sun.
What is the Milky Way?
The Milky Way galaxy is a collection of gas, dust, planets, and stars. This galaxy includes our solar system.
What is the difference between the 3 different types of galaxies?
Spiral galaxies have both young and old stars. Spiral in shape.
Elliptical galaxies have old stars. Egg-shaped.
Irregular galaxies generally have young stars. Not a specific shape.
What color are the hottest stars?
Blue stars.
What color are the coolest stars?
Red stars
Describe the lifecycle of stars.
After the fuel inside a star is finished, all stars become red giants. Next, depending on how massive the star is, the star will either stop glowing and turn into a white dwarf, or will explode into a sueprnova
