The Ring Nebula (image below) is a planetary nebula that currently has a radius of 0.4 pc and an expansion velocity of 250 km/s.Approximately how long ago did its parent star die and eject its outer layers? 
Definitions:
New Deal
During the 1930s, President Franklin D. Roosevelt introduced a variety of programs, public works, monetary reforms, and regulations in the United States, all aimed at mitigating the effects of the Great Depression.
Federal Housing
Refers to government programs aimed at ensuring Americans have access to affordable housing, often through subsidies or public housing projects.
Balanced Power
A situation in international relations where power is distributed among various nations so that no single nation can dominate or interfere significantly with others.
Supreme Court
The highest federal court in the United States, consisting of nine Justices and having ultimate jurisdiction over all federal court cases and state court cases involving issues of federal law or the Constitution.
Q5: A red photon has a wavelength of
Q7: Why are auroras visible mostly at the
Q12: Define cloud cannibalism.Where is it observed in
Q19: Examine the figure below.By studying how the
Q21: Speculation involves delaying production until orders are
Q24: During the main-sequence evolution of a massive
Q27: Uranus and Neptune do not have bands
Q27: Which of the following is NOT true
Q31: Does the wavelength of a wave change
Q37: What is the evidence that galaxies form