2nd Six Weeks Science Test Review

Vocabulary practice flashcards covering astronomy, stellar evolution, the H-R diagram, ocean tides, thermal convection, and meteorology.

Milky Way

The spiral galaxy in which our solar system is located.

The three primary shapes that galaxies take in space:

spiral, elliptical, and irregular.

Sagittarius A*

The supermassive black hole located at the central core of our galaxy.

The Sun

A yellow, medium-sized main sequence star located in the arms of the Milky Way galaxy rather than at its center.

Life Cycle of Our Sun

The sequential evolutionary stages of a medium-sized star: Nebula $\rightarrow$ Protostar $\rightarrow$ Main Sequence $\rightarrow$ Red Giant $\rightarrow$ White Dwarf $\rightarrow$ Black Dwarf.

Nebula

A cloud of gas and dust in space that serves as a "stellar nursery" where new stars are born.

Hertzsprung-Russell (H-R) Diagram

An astronomical chart used to classify stars based on two main categories: luminosity and temperature.

Kelvin ($K$)

The temperature scale used to measure stellar surface temperatures on the H-R diagram, where values increase from right to left.

Main Sequence

The prominent diagonal band on the H-R diagram that contains approximately $90\%$ of all stars.

Red Giants

Cool, high-luminosity stars that belong to the spectral classes $K$, $M$, and $G$.

Low Mass Star

A star with a mass of $0.8$ to $8$ solar masses that expands into a red giant, releases a planetary nebula, and leaves behind a white dwarf that cools into a black dwarf.

High Mass Star

A star with a mass of $8$ to $150$ solar masses that expands into a red supergiant and explodes as a supernova, ultimately ending as a neutron star or a black hole.

White Dwarf

A small, dense, hot, and dim stellar remnant characterized on the H-R diagram by high temperature (e.g., $15{,}000\,K$) and low luminosity (e.g., $0.01$).

Spring Tide

A tide characterized by the greatest tidal range, occurring when the Earth, Moon, and Sun align during New Moon and Full Moon phases.

Neap Tide

A tide characterized by the least tidal difference, occurring when the Moon is at a right angle to the Sun during the First Quarter and Last Quarter phases.

Equator

The region of the Earth that receives the most direct amount of sunlight throughout the year.

Global Ocean Currents

Circulating patterns in which warm currents flow away from the equator along the east coasts of continents, while cold currents flow toward the equator along the west coasts of continents.

Convection

A thermal fluid process where hotter, less dense fluids or air rise, while colder, denser fluids or air sink.

Differential Heating of Land and Water

The principle that land heats up and cools down significantly faster than water ("Land always wins").

Sea Breeze

A daytime coastal breeze that blows from the ocean toward the land, driven by warmer air rising over the heated land and cooler, denser marine air moving inland to replace it.

High-Pressure System ($H$)

A weather system that typically brings clear skies, cooler air, and dry weather conditions (located near Seattle and Dallas on the review map).

Low-Pressure System ($L$)

A weather system associated with rising air, cloud formation, and precipitation (located near Minneapolis on the review map).

Weather Front

A boundary separating two different air masses where weather changes and precipitation frequently occur.

Hurricane

A severe rotating tropical storm that forms over warm ocean water as thermal energy creates large low-pressure areas, rotating counter-clockwise in the Northern Hemisphere.