Star Life & Death
The stage of stellar life that represents the longest and most stable period for most stars.
What is the Main Sequence?
The universally accepted approximate age of the universe.
What is 13.8 billion years?
The collective name for the first four planets, characterized by being rocky, dense, and small.
What are the Terrestrial Planets?
The mechanism of heat transfer that moves energy from the Sun’s interior to its surface via circulating currents of hot gas.
What is Convection?
The celestial object that is made of billions of stars, gas, and dust held together by gravity.
What is a Galaxy?
The type of star that is extremely cool (low surface temperature) and extremely luminous, often found in the top-right of the H-R diagram.
What is a Red Giant or Red Supergiant?
This piece of evidence shows that galaxies are moving away from us, supporting the expanding universe model.
What is Redshift?
The specific oval shape of all planetary orbits, defined by two foci.
What is an Ellipse?
The process that generates the immense energy released by stars.
What is Nuclear Fusion (specifically, the fusion of Hydrogen into Helium)?
A small, icy body that forms a noticeable tail when it nears the Sun, unlike its rocky counterpart.
What is a Comet (as opposed to an Asteroid)?
The two opposing forces that are in balance during most of a star's life.
What are Gravity (inward) and Nuclear Fusion/Radiation Pressure (outward)?
Uniform, faint, leftover thermal energy that is found throughout the universe.
What is Cosmic Microwave Background Radiation (CMBR)?
The planet in our solar system that has the longest period of revolution (orbit around the Sun).
What is Neptune?
The relationship between the wavelength and frequency of electromagnetic radiation.
What is an inverse relationship (as wavelength increases, frequency decreases)?
The orbital property that measures how elongated or stretched a planet’s elliptical orbit is.
What is Eccentricity?
The type of relationship between a star’s mass and its lifespan.
What is an inverse relationship (higher mass = shorter lifespan)?
The two primary elements that were created and distributed in the immediate aftermath of the Big Bang
What are Hydrogen and Helium?
Describe the relationship between a planet's average orbital speed and its distance from the Sun.
What is an inverse relationship (as distance increases, orbital speed decreases)?
All stars with the highest mass and shortest lifespans have this surface color.
What is Blue (or Blue-White)?
The primary difference between Terrestrial (inner) and Jovian (outer) planets, based on their material and density.
What is the Terrestrial planets are rocky/metallic and have high density, while Jovian planets are gaseous and have low density?
What happens to a star’s diameter when it exhausts hydrogen in its core and moves into the giant phase?
What is increases (expands), causing the star's surface temperature to decrease and its luminosity to increase?
The proportion of the two simplest elements that is observed in the universe that strongly supports the Big Bang Theory.
What is the 3:1 ratio of Hydrogen to Helium? Or (about 75% to 25%)
Describe two ways the diameter, mass, and density of Jovian planets compare to those of Terrestrial planets.
What are larger diameter, greater mass, and lower density (or less dense)?
Describe the difference in the amount of energy produced in nuclear reactions as compared to chemical reactions.
What is Nuclear reactions produce exponentially more energy (or vastly greater energy) than chemical reactions?
Describe the difference between a star and a stellar gas cloud (nebula) that relates to energy generation.
What is a Star is undergoing nuclear fusion while a Stellar Gas Cloud is not (or a gas cloud is the raw material for a star)?