Earth Science and Astronomy Lecture Review

Vocabulary practice flashcards covering fundamental scientific concepts, planetary motions, celestial phenomena, atmospheric structure, and gravity based on lecture notes.

Observation

Directly perceiving something using senses (e.g., "The sky is blue.").

Inference

A conclusion drawn based on observations (e.g., "It is daytime because the sky is blue.").

Qualitative Observations

Descriptive data obtained through observation, such as color and texture.

Quantitative Observations

Numerical data obtained through observation, such as temperature and mass.

Independent Variable

The variable in an experiment that is changed (e.g., amount of sunlight).

Dependent Variable

The variable in an experiment that is measured (e.g., plant growth).

Controlled Variables

Constants kept the same throughout an experiment (e.g., type of plant, soil type).

Meteoroid

A small rock or particle in space.

Meteor

A meteoroid that enters Earth's atmosphere and produces a streak of light (a shooting star).

Meteorite

A meteoroid that survives its passage through Earth’s atmosphere and lands on the surface.

Cosmic Microwave Background Radiation

Remnant radiation that represents leftover heat from the early universe, serving as evidence supporting the Big Bang Theory.

Redshift of Galaxies

Observations showing that distant galaxies are moving away, indicating that the universe is expanding.

Polaris

The current North Star positioned directly above Earth's North Pole, serving as a navigation aid because it remains relatively fixed in the night sky.

Precession

The slow change or wobble of Earth's axis that causes the identity of the North Star to change over time.

Rotation

A planet spinning on its axis, taking $24\text{ hours}$ for Earth and $27.3\text{ days}$ for the Moon.

Revolution

A celestial body orbiting another body, taking $365.25\text{ days}$ for Earth around the Sun and $27.3\text{ days}$ for the Moon around Earth.

Kepler’s First Law (Law of Ellipses)

Planets move in elliptical orbits with the Sun located at one focus.

Kepler’s Second Law (Law of Equal Areas)

A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.

Kepler’s Third Law (Law of Harmonies)

The square of a planet's orbital period is proportional to the cube of the semi-major axis of its orbit.

Spring Tides

Tides that occur during full and new moons when gravitational forces of the Moon and Sun align, resulting in higher high tides and lower low tides.

Neap Tides

Tides that occur during the first and last quarters of the moon when the gravitational forces of the Moon and Sun are perpendicular, resulting in lower high tides and higher low tides.

Lunar Eclipse

An event where Earth blocks sunlight from reaching the Moon, causing the Moon to pass through Earth's shadow (umbra and penumbra).

Solar Eclipse

An event where the Moon blocks sunlight from reaching Earth, causing the shadow of the Moon (umbra and penumbra) to fall on Earth.

Reason for Seasons

The tilt of Earth's axis (approximately $23.5^\circ$), leading to varying angles and intensities of sunlight throughout the year despite a nearly circular orbit.

Density

Mass per unit volume; affects buoyancy such that lower density substances rise higher in a fluid (like the atmosphere).

Troposphere

The densest layer of Earth's atmosphere, where weather occurs.

Stratosphere

The atmospheric layer containing the ozone layer, which absorbs UV radiation.

Mesosphere

The atmospheric layer where meteors burn up.

Thermosphere

The atmospheric layer characterized by high temperatures and the occurrence of the aurora borealis.

Exosphere

The outermost atmospheric layer, where satellites orbit.

Nuclear Fusion

The process where hydrogen nuclei combine to form helium, releasing energy in the form of heat and light and powering stars.

Gravitational Force Formula

$F = \frac{G m_1 m_2}{r^2}$, where $F$ is the force of gravity, $m_1$ and $m_2$ are masses, $r$ is the distance between centers, and $G$ is the gravitational constant.

Insolation

Incoming solar radiation at a given location.

Umbra and Penumbra

The shadow regions cast during lunar and solar eclipses.