sphere articles
What is the actual geometric shape of Earth?
Approximately what percentage of Earth's surface is covered by water?
Roughly how long ago did the genesis of Earth occur?
Which hypothesis explains the formation of the Moon and the final stages of Earth’s differentiation?
What process established Earth's layered interior structure?
In terms of average density, how does Earth rank among the planets in the Solar System?
What is the physical state of the outer core and what crucial feature does it generate?
What are the two most abundant gases composing Earth's atmosphere?
What astronomical feature is the direct cause of the seasons experienced on Earth?
What vital role does plate tectonics play in stabilizing Earth's long-term climate?
What condition must a plane satisfy to create a great circle when intersecting a sphere?
How does the radius of a great circle compare to the radius of the sphere it lies upon?
What do lines of longitude, such as meridians on Earth, represent geometrically?
If two points chosen on a sphere are antipodal, how many great circles can pass through both?
Which terrestrial example is cited as the most famous great circle on Earth?
What geometric feature distinguishes a great circle from any other circle drawn on a sphere?
What is the term for the shortest path between two points along the surface of a sphere?
How many unique great circles are defined by two distinct, non-antipodal points on a sphere?
What are most lines of latitude, such as the Tropic of Cancer, classified as geometrically on Earth?
In the mathematical definition of a great circle plane ($ax + by + cz = 0$), what does the vector $(a, b, c)$ represent?
What causes a flight path between distant cities to appear as a wide, curved arc on a flat Mercator projection map?
What is the typical stellar population size of a globular cluster?
How ancient are globular clusters generally considered to be?
How do globular clusters contrast visually and structurally with open clusters?
What frequent dynamic event characterizes the extremely dense core of a globular cluster?
What specific type of star can evolve as a result of the high-density environment in a cluster core?
In a large spiral galaxy like the Milky Way, where are globular clusters predominantly situated?
Compared to open clusters, what is characteristic of the orbital paths of globular clusters around a galaxy's center?
What is the approximate typical diameter spanned by a globular cluster containing up to ten million stars?
What real-world factor often prevents a globular cluster from being a *perfectly* spherical shape?