Cosmology
This cosmological model states that the universe expanded rapidly from a hot, dense singularity approximately 13.8 billion years ago.
What is the Big Bang Theory?
The core process that powers active stars by fusing Hydrogen nuclei into Helium.
What is Nuclear Fusion?
Also known as the Habitable Zone, this is the region around a host star where liquid water can stably exist on a planet's surface.
What is the Goldilocks Zone?
Earth's seasons are caused by its revolution around the Sun and this constant tilt angle relative to its orbital plane.
What is 23.5 degrees?
This term describes a heavier, bolder contour line labeled with a specific numerical elevation.
What is an Index Contour?
Discovered as uniform low-energy radiation across space, this acts as the leftover thermal "afterglow" of the early universe.
What is Cosmic Microwave Background (CMB) radiation?
This state of balance occurs when outward radiation pressure from nuclear fusion equals the inward pull of gravity.
What is Hydrostatic Equilibrium?
According to the Nebular Hypothesis, this process occurs when dust grains stick together via electrostatic and gravitational forces to form planetesimals.
What is Accretion?
This type of eclipse occurs when the Earth passes directly between the Sun and the Moon, casting a shadow on the Moon.
What is a Lunar Eclipse?
On a topographic map, contour lines spaced close together indicate this type of terrain slope.
What is a steep slope?
According to Big Bang predictions, the early universe was composed of approximately 75% Hydrogen and 25% of THIS element.
What is Helium?
Approximately 90% of all stars, including our Sun, sit in this diagonal band on the Hertzsprung-Russell (H-R) diagram while actively fusing Hydrogen.
What is the Main Sequence?
Temperatures outside of this critical boundary allowed volatile ice compounds to condense, leading to the formation of gas giants.
What is the Frost Line?
A Solar Eclipse can only occur during this specific phase of the Moon.
What is a New Moon?
According to the Stream V-Rule, when contour lines cross a river, the "V" shape points in this direction relative to water flow.
What is upstream (or toward higher elevation/opposite direction of flow)?
Named after a famous law, this phenomenon occurs when light from distant galaxies shifts toward longer wavelengths as they move away from us.
What is Redshift (or Hubble's Law)?
Unlike average stars that end as White Dwarfs, high-mass stars end their expansion phase in a violent explosive event known as this.
What is a Supernova?
Planetary life relies on a molten metallic core to generate this protective shield against solar winds and cosmic radiation.
What is a Magnetosphere?
During an eclipse, this term refers to the dark, central cone of shadow where light is completely blocked.
What is the Umbra?
Closed contour loops containing specific marks represent this terrain feature.
What is a depression?
This effect explains how light wavelengths compress into a "blueshift" when an object moves toward an observer and stretch out into a "redshift" when moving away.
What is the Doppler Effect?
If a high-mass star's core remnant exceeds this mass threshold following a supernova, it will collapse into a Black Hole rather than a Neutron Star.
What is 3 Solar Masses (3M)?
Inner terrestrial planets are primarily composed of silicates and these materials because only they could condense at high temperatures inside the Frost Line.
What are Metals?
Occurring around March 21 and September 23, these events happen when Earth's axis is perpendicular to solar rays, resulting in equal 12-hour days and nights.
What are Equinoxes (Vernal and Autumnal Equinoxes)?
This current NASA-led lunar initiative aims to establish a sustainable human presence on the Moon and prepare for deep-space missions.
What is the Artemis Program?