What is it in the solar wind that causes the aurora in the Earth’s atmosphere?
Protons and electrons.
Why are the globular clusters good places to watch for type II supernova explosions?
Globular clusters tend to contain many stars in the 10-30 solar mass range.
Globular clusters frequently collide with each other to produce type II supernovas.
Globular clusters are not good places to watch for type II supernovas because these clusters are typically too old to harbor such massive stars.
Globular clusters contain many white dwarf stars in binary pairs, and these can explode as type II supernovae.
What are the primary ingredients of a comet?
Methane, ammonia, carbon monoxide, titanium.
Hydrogen, silicon, carbon, oxygen, and mercury.
Iron, nickel, sodium, silicon, nitrous oxide.
Water, dust, alcohol, ammonia, carbon dioxide, and amino acids.
Cosmologists refer to “the decoupling event.” What do they mean by that?
The rapid expansion of space just after the first fraction of a second of the Big Bang.
The time when protons and neutrons first formed.
The formation of the first stars prior to the formation of galaxies.
The time when radiation had cooled enough to allow neutral atoms to form.
According to Einstein, which of these best explains a black hole?
The curvature of spacetime near a large mass is so severe that even light is too slow to reach escape velocity.
A massive star is sucking in everything near it.
A tiny object has ripped the fabric of space and connected one part of the Universe to another.
The opposite of a big bang.
Suppose an object radiates in the visible range of light. We also see steady pulses of intense radio and visible light with a time interval of 0.15 seconds between pulses. Occasionally we detect powerful bursts of X-rays from the object. Choose the best theory.
A pulsar with an accretion disk from a visible star, and the orbit plane is oriented so that we see no eclipsing.
A quasar at the center of interacting galaxies, which in turn are orbiting each other very quickly.
A black hole-visible star binary pair with short orbital period.
A supermassive black hole.
If our solar system were half-way from the center to the edge of a giant elliptical galaxy, how would our night sky look different?
We would see pretty much the same kind of night sky as we see now.
We would see no hazy band of “milky way” and we would see dust clouds all around the sky, with fewer stars.
We would see a much wider band of hazy light like the “milky way” and we would see a lot fewer stars.
We would see no hazy “milky way” arcing across the sky, but we would see more stars overall, and very few or no dust clouds at all.