Comprehensive Review of Solar System, Stars, and Cosmology Concepts

Venus

A planet similar in size to Earth but with a very different atmosphere and surface conditions, primarily composed of carbon dioxide, leading to a runaway greenhouse effect.

Mars

A smaller planet with a similar atmospheric composition to Venus, featuring large surface features such as mountains and impact craters, and evidence of past water.

Runaway Greenhouse Effect

A process where a planet's atmosphere traps heat, leading to extremely high surface temperatures, as seen on Venus.

Olympus Mons

The largest volcano in the solar system located on Mars, whose eruption history can be estimated through crater counting.

Giant Planets

Jupiter, Saturn, Uranus, and Neptune, which are primarily composed of hydrogen and helium and have no solid surfaces.

Gas Giants

Planets like Jupiter and Saturn that are primarily made of gases and have strong magnetic fields.

Ice Giants

Planets like Uranus and Neptune that contain significant amounts of water, ammonia, and methane in their composition.

Magnetosphere

The region around a planet dominated by its magnetic field, which can cause auroras.

Cryovolcanism

Volcanic activity that involves the eruption of volatile substances like water, ammonia, or methane, rather than molten rock.

Enceladus

A moon of Saturn known for its cryovolcanic activity that contributes material to Saturn's E-ring.

Titan

Saturn's largest moon, notable for having a dense atmosphere and surface lakes of methane and ethane.

Pluto

A dwarf planet in the Kuiper Belt, known for its small size and multiple moons.

Kuiper Belt

A region of the solar system beyond Neptune, containing many icy bodies and remnants from the solar system's formation.

Comet

An icy body that, when passing close to the sun, develops a tail and coma due to sublimation of its ices.

Meteor Shower

A celestial event where numerous meteors are observed to radiate from one point in the night sky, often caused by Earth passing through debris left by comets.

Exoplanets

Planets that orbit stars outside our solar system, detected through various methods such as transit and Doppler shift.

Habitable Zone

The region around a star where conditions may be suitable for life as we know it, typically where liquid water can exist.

Drake Equation

A formula used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy.

Luminosity

The total amount of energy emitted by a star per unit time, often measured in watts.

Brightness

The amount of light received from a star as observed from Earth, which can be affected by distance and the star's luminosity.

Spectroscopy

A technique used to analyze the light spectrum emitted or absorbed by objects, providing information about their composition and properties.

HR Diagram

A graphical representation of stars plotted according to their luminosity and temperature, showing the relationship between stellar evolution stages.

Type 1 Supernova

A supernova that occurs in binary systems when a white dwarf accumulates matter from its companion star, leading to a thermonuclear explosion.

Type 2 Supernova

A supernova resulting from the gravitational collapse of a massive star after it has exhausted its nuclear fuel.

North Star

Also known as Polaris, it is used for navigation as it is located nearly directly above the North Pole.

Celestial Sphere

An imaginary sphere surrounding Earth, onto which all celestial bodies can be projected for observational purposes.

Equatorial Coordinate System

A system for locating celestial objects based on their right ascension (RA) and declination (DEC) relative to the celestial equator.

What is the altitude-azimuth coordinate system?

A celestial coordinate system that specifies the position of objects in the sky using altitude (angle above the horizon) and azimuth (angle along the horizon from the north).

What is diurnal variation of the night sky?

The apparent motion of stars and celestial objects across the sky due to the Earth's rotation, including the visibility of circumpolar stars that never set below the horizon.

What is a meridian diagram?

A sketch that represents the local sky, showing the celestial poles, celestial equator, and the apparent motion of stars as viewed from a specific location on Earth.

Why do we see certain constellations only at certain times of the year?

Constellations are visible at different times of the year due to the Earth's orbit around the Sun, which changes our perspective of the night sky.

What are the solstice and equinox dates related to?

They are related to the right ascension (RA) and declination (DEC) of the Sun, marking the changing seasons.

How does the tilt of the Earth's rotational axis cause seasons?

The tilt causes different parts of the Earth to receive varying amounts of sunlight throughout the year, leading to seasonal changes.

What is the reason we see the same side of the Moon?

The Moon's orbital period is equal to its rotational period, resulting in synchronous rotation.

What causes the phases of the Moon?

Phases are caused by the changing geometry of the Sun, Moon, and Earth, affecting how much of the Moon's illuminated hemisphere we can see.

What phase of the Moon causes a solar eclipse?

A solar eclipse occurs during the new moon phase when the Moon is positioned between the Earth and the Sun.

What phase of the Moon causes a lunar eclipse?

A lunar eclipse occurs during the full moon phase when the Earth is positioned between the Sun and the Moon.

What are the two regions of a shadow during an eclipse?

The two regions are the umbra (the fully shaded inner region) and the penumbra (the partially shaded outer region).

What are the three types of solar eclipses?

The three types are partial, total, and annular solar eclipses, which differ based on the alignment and distances of the Earth, Moon, and Sun.

What is the significance of the line of nodes in lunar eclipses?

The line of nodes indicates where the Moon's orbit intersects the Earth's orbital plane, determining when eclipses can occur.

What arguments did the Greeks use to show that the Earth was a sphere?

They observed the circular shadow of the Earth on the Moon during a lunar eclipse and noted that ships disappear hull-first over the horizon.

What is the Ptolemaic model of the solar system?

A geocentric model where the Earth is at the center, and all celestial bodies, including the Sun and planets, orbit around it.

What was the purpose of epicycles in the geocentric model?

Epicycles were used to explain the retrograde motion of planets by adding smaller circular orbits to the main circular orbits.

What was Copernicus's contribution to astronomy?

He proposed a heliocentric model of the solar system, placing the Sun at the center and explaining planetary motion more elegantly than the geocentric model.

How did Tycho Brahe contribute to astronomy?

He made detailed and accurate observations of celestial bodies without a telescope, challenging the notion of perfect heavens.

What are Kepler's three laws of planetary motion?

1) Planets move in elliptical orbits with the Sun at one focus, 2) A line connecting a planet to the Sun sweeps out equal areas in equal times, 3) The square of a planet's orbital period is proportional to the cube of its average distance from the Sun.

What is Newton's law of universal gravitation?

It states that every mass attracts every other mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

What is the greenhouse effect?

The warming of a planet's surface due to the trapping of heat by its atmosphere, primarily caused by greenhouse gases.

What is the solar wind?

A stream of charged particles released from the upper atmosphere of the Sun, consisting mainly of electrons and protons.

What is the solar cycle?

An approximately 11-year cycle during which solar activity, including sunspots and solar flares, varies in intensity.

What are the four basic geological processes on a planet?

Impact cratering, tectonics, volcanism, and erosion.

What is the current theory for the formation of the Moon?

The Giant Impact Hypothesis suggests the Moon formed from debris ejected after a Mars-sized body collided with the early Earth.