What's the Matter?
This force of attraction between all matter is one of the four fundamental forces of nature. (double or nothing: name all four fundamental forces)
What is gravity?
(What are gravity, electromagnetism, strong force, and weak force?)
This is the name for the current prevailing idea for the formation of the Moon.
What is the Giant Impact Hypothesis?
This is the third brightest object in the sky after the Sun and Moon.
What is Venus?
This is another name for the power emitted by a star.
What is luminosity?
If a star is massive enough, it may collapse quickly enough to rebound into this violent explosion.
What is a supernova?
This is the name for the process by which small masses clump together into larger masses due to gravity.
What is accretion?
This is the name for the region of space affected by Earth's magnetic field.
What is the magnetosphere?
All of the inner planets have similar internal structure, with metal-rich cores and outer layers made of these materials.
What are silicates?
While measurements of its radius have a large error range, this star has the biggest upper estimate of size of any known star.
What is Stephenson 2-18?
This is the first element for which additional fusion no longer produces a net energy output, and whose buildup in a star's core means the star's death is imminent.
What is iron?
Electrons are approximately this many times less massive than protons.
What is one thousand?
Surrounding Earth are two charge-trapping radiation belts named for this astrophysicist.
Who is (James) Van Allen?
This is the controversial hypothesis that life is spread throughout the universe by traveling astronomical bodies, and therefore did not originate on Earth.
What is panspermia?
What is the convection zone?
This hypothetical astronomical body is allowed for by Einstein's Theory of Relativity, but has never been observed in reality.
What is a white hole? (Alternative answer: What is a primordial black hole?)
Protons, neutrons, and electrons all belong to this category of quantum particles. (hint: the answer is not "subatomic")
What are fermions?
This is the technical term for lunar soil, the coating of dust from impacts on the surface of the Moon.
What is regolith?
Each body within the asteroid belt is on average this distance away from its closest neighbor.
What is one million kilometers?
One of the most important tools in astronomy is this luminosity vs. temperature chart, used to classify stars graphically.
What is a Hertzsprung-Russell diagram?
The phenomenon of degeneracy pressure is explained by the exclusion principle, a quantum law discovered by this physicist.
Who is Wolfgang Pauli?
This is the original name for the SI base unit of mass, which was renamed the kilogram in order to avoid associations with the French nobility.
What is the grave?
Earth's magnetic axis is tilted by approximately this many degrees with respect to Earth's rotational axis.
What is eleven?
Pluto was discovered by American Clyde Tombaugh, who is the great uncle of this Dodgers legend, who just last night became only the 20th pitcher ever to strike out 3,000 batters.
Who is Clayton Kershaw?
The heliopause is the heliosphere's outermost boundary. This is the name of the layer of the heliosphere just before the heliopause.
What is the heliosheath?
This is the name of the process wherein extreme temperatures and pressures crush protons and electrons together into neutrons, which is necessary to form a neutron star.
What is electron capture?