astrology

*What is Electromagnetic Radiation?*

A form of energy emitted and absorbed by charged particles that exhibits wave-like behavior.

*What does electromagnetic radiation include?*

Includes various types of waves:

- Visible light

- Radio waves

- X-rays

- Gamma rays

*How fast does electromagnetic radiation travel?*

Travels at the speed of light (~ 3 x 10^8 m/s).

*What is the relationship between frequency and wavelength?*

Classifies electromagnetic radiation based on:

- *Wavelength:* Distance between wave crests

- *Frequency:* Number of waves passing a point per second

*What types of telescopes are there?*

Two main types:

- *Refracting telescopes*

- *Reflecting telescopes*

*What are refracting telescopes used for?*

Use lenses to bend light and focus it at a single point.

*What are reflecting telescopes used for?*

Use mirrors to focus light, enabling larger objectives and clearer images.

*What is the Hubble Space Telescope?*

Launched in 1990, it observes in near-UV, visible, and IR wavelengths, providing clear images beyond Earth's atmosphere.

*What advantages does the Hubble Space Telescope have over land-based telescopes?*

- No atmospheric interference

- Can observe a broader range of wavelengths

- Provides clearer, more accurate images

*Why is the albedo of the Moon so low?*

Moon's albedo is low because the Moon's surface is covered with regolith, which does not reflect much light.

*Distinguish between highlands and maria.*

- *Highlands:* Heavily cratered, light-colored, mountainous areas

- *Maria:* Smooth, dark areas formed by lava that filled large craters

*What are other features commonly seen on the Moon?*

- *Ejecta:* Material blasted out during impacts

- *Rays:* Lines of ejecta radiating outward from craters

- *Rilles:* Valley-like structures, possibly from collapsed lava tubes

*What is the Moon composed of?*

Primarily silicates (silicon and oxygen).

*Is the Moon tectonically active?*

Yes, moonquakes occur due to tidal dynamics, meteorite impacts, and thermal contraction.

*Discuss the three formation theories of the Moon.*

- *Formation Theory:* Moon formed from debris after a collision with Earth.

- *Fission Theory:* A piece of Earth spun off and became the Moon.

- *Capture Theory:* Moon was captured by Earth's gravity from elsewhere in space.

*Why did Americans and Russians visit the Moon?*

- *Technological demonstration*

- Asserted dominance in space exploration

*Distinguish between rotation and revolution.*

- *Rotation:* Spinning of an object on its axis

- *Revolution:* Movement of one object around another (orbital movement)

*What is synchronous rotation?*

When an object's rotational period matches its orbital period, like the Moon.

*Define eccentricity.*

Eccentricity is the measure of how elliptical (oval) an orbit is.

*How are apogee and perigee, aphelion and perihelion related to eccentricity?*

- *Apogee & Perigee:* Applied to objects orbiting Earth.

- *Aphelion & Perihelion:* Applied to objects orbiting the Sun.

- Eccentricity increases as the distance between apogee/perigee or aphelion/perihelion increases, making the orbit more elongated.

*Know the phases of the Moon.*

- *New Moon*

- *Waxing Crescent*

- *First Quarter*

- *Waxing Gibbous*

- *Full Moon*

- *Waning Gibbous*

- *Third Quarter*

- *Waning Crescent*

*Distinguish between solar and lunar eclipses.*

- *Solar Eclipse:* Moon blocks the Sun, causing darkness on Earth.

- *Lunar Eclipse:* Earth blocks the Sun's light from reaching the Moon, causing a reddish appearance.

*How are gravity and tides related?*

- The gravitational pull from the Moon and the Sun causes Earth's oceans to bulge, creating high and low tides.

*How are gravity and orbits related?*

- Gravity pulls objects toward larger bodies, while their forward motion keeps them in a continuous orbital path.

*Geocentric vs. heliocentric: what's it all about?*

- *Geocentric Model (Ptolemy):* Earth is at the center of the solar system.

- *Heliocentric Model (Copernicus & Galileo):* Sun is at the center of the solar system.

*What causes the seasons on Earth?*

The tilt of Earth's axis (25.3 degrees) relative to its orbital plane causes the seasons.

*What is precession?*

Precession is the gradual wobble of Earth's rotational axis due to gravitational forces from the Sun and Moon.

*What is the equation for eccentricity?*

*Eccentricity = (distance between foci) / (length of major axis).*

*Who was Milankovitch and what does he have to do with Earth's motions?*

Milutin Milankovitch proposed that changes in Earth's orbital shape, axial tilt, and precession influence long-term climate patterns and ice ages.

*Describe the steps involved in the formation of the solar system.*

1. Collapsing Interstellar cloud

- Stars + planets form from interstellar clouds (nebulae) which are made of hydrogen and helium gas

2. Collapse accelerates

3. Matter condenses

Rotating disk around the young sun caused temperatures to vary causing matter to condense into different elements and compounds

4. Planetesimals (Mini Planets)

Colliding particles that merged after the matter condensed and can merge and collide to become planets through collisions.

5.Gas giant planets form

JUPITER FORMSSS (through the merging of icy planetesimals)

Saturn and other gas giants came after because jupiter collected so much aura that it became the largest gas giant

6. Terrestrial planets form

After the gas giants the inner planets were formed near the young sun and were made of materials that wouldn't vaporize by being close to the sun

ROCKY and DENSE

7. Debris

Material that remained after the formation of the planets and satellites

Some became comets (icy)

Some became asteroids (Rocky)

*What are Kepler's three laws?*

- *First Law:* Orbits are elliptical.

- *Second Law:* Planets sweep equal areas in equal times.

- *Third Law:* p² = a³ (orbital period in Earth years squared equals semi-major axis in AU cubed).

*What is retrograde motion?*

Retrograde motion occurs when a planet appears to move backward due to Earth overtaking slower-moving outer planets.

*How are the characteristics of the inner planets similar?*

- All are rocky, have small sizes, and are close to the Sun.

- High density.

*How are the inner planets different from each other?*

- *Mercury:* Extreme temperature variation.

- *Venus:* Hottest and brightest.

- *Earth:* Supports life with liquid water.

- *Mars:* Known for its red surface and volcanoes.

*What occurs on Earth that occurs on no other planets?*

- Tectonic activity and liquid water.

*How are the gas giant planets similar to each other?*

- Large size, primarily gas composition, multiple moons, rings, and a core.

*What is a unique difference for each outer planet?*

- *Jupiter:* Great Red Spot

- *Saturn:* Prominent rings

- *Uranus:* Extreme axial tilt

- *Neptune:* Distinctive clouds and rings

*How do moons and rings form?*

- Moons form from debris, often through collision.

- Rings are formed from smaller debris or leftover material.

*How are gas giants similar to the Sun?*

- Both are made of gas, have large sizes, strong gravity, and have a central core surrounded by layers.

*How do dwarf planets differ from planets?*

- Dwarf planets orbit the Sun but are too small to clear their orbits of other debris.

*How many dwarf planets are there?*

- Five officially recognized dwarf planets: Pluto, Eris, Haumea, Makemake, Ceres.

*How do asteroids, meteoroids, meteors, and meteorites differ?*

- *Asteroids:* Rocky bodies in space.

- *Meteoroids:* Smaller fragments of asteroids.

- *Meteors:* Meteoroids entering Earth's atmosphere.

- *Meteorites:* Meteoroids that land on Earth.

*Where is the Kuiper Belt?*

- Located beyond Neptune's orbit, between 30-55 AU from the Sun. Contains icy bodies and dwarf planets.

*Describe a comet in terms of structure, orbit, and appearance.*

- Comets have a nucleus, coma, and tail.

- Elliptical orbit with a bright tail when near the Sun.

*Where is the Oort Cloud?*

- Around 2,000-100,000 AU from the Sun, it contains icy bodies and is the origin of long-period comets.

*What are the layers of the Sun?*

- Core

- Radiative Zone

- Convective Zone

- Photosphere

- Chromosphere

- Corona

*Which layer of the Sun can we see?*

- We can see the *photosphere* (visible layer).

*Can we see any other layers of the Sun?*

- The *chromosphere and corona* can be seen during a solar eclipse.

*What surface features are found on the Sun?*

- *Sunspots:* Cooler areas of magnetic activity.

- *Solar prominences:* Large eruptions of gas.

- *Solar flares:* Explosive bursts of energy.

*What is the solar wind?*

- A stream of charged particles (mainly electrons and protons) flowing from the Sun's corona into space.

*How is energy produced in the Sun?*

- Through nuclear fusion in the core, where hydrogen atoms fuse to form helium, releasing energy.

*What are the three types of spectra?*

- *Continuous spectrum:* All colors of light.

- *Emission spectrum:* Light emitted by hot gases.

- *Absorption spectrum:* Light absorbed by cooler gases.

*Which type of spectrum does the Sun show?*

- The Sun shows an *absorption spectrum*.

*What is the composition of the Sun?*

- 74% hydrogen, 24% helium, and 2% heavier elements.

*How do we know the composition of the Sun?*

- Through *spectroscopy*, analyzing light emitted from the Sun to identify its chemical elements.

*What are the theories of formation of the solar system, Earth, and Moon?*

- *Solar system:* Formed from a collapsing interstellar cloud.

- *Earth:* Formed as a rocky planet.

- *Moon:* Formed through impact, fission, or capture theories.

Longer wavelength (e.g., radio waves) means what frequency

lower frequency.

Shorter wavelength (e.g., gamma rays) means what frequency

higher frequency