Pluto is best described as a ____.
What is a Kuiper Belt Object?
Within a stellar system, stars and planets orbit a common ____.
What is a center of mass?
The layer of the Sun that we see with our eyes.
What is the photosphere?
The location within the Milky Way where most star formation occurs.
What are the spiral arms?
We infer the existence of ____ due to its observed influence on regular matter.
What is dark matter?
Comets display these when they are within 5 AU from the Sun.
What are tails?
The larger the decrease in a star's brightness as a planet transits in front of its star, the larger the ____ of the planet.
What is radius?
A star that is destined to die in a supernova explosion.
What is a high-mass star?
You observe the periodic brightening and dimming of a Cepheid variable star in another galaxy. From this, you can calculate this galaxy's ____.
What is distance?
Astronomers studying white dwarf supernovae in the 1990s were surprised to learn that the expansion rate of the Universe was ____.
What is accelerating?
A temporary high-pressure storm on Neptune.
What is a Great Dark Spot?
The method which seeks to detect planets by measuring small changes in the positions of stars in the sky.
What is astrometry?
The location of red giants on the HR Diagram.
What is the upper right?
The spiral arms of the Milky Way (and other spiral galaxies) are regions of higher ____ which can cause incoming nebulae to compress and form new stars.
What is density?
This is revealed when mapping the sky positions and distances to galaxy groups and clusters
What is large-scale structure?
The most abundant gas in Titan's atmosphere.
What is Nitrogen?
The transit method allows you to measure the radius of a planet, whereas the Doppler method allows you to measure the ____ of a planet.
What is mass?
Stars form most easily in clouds that are ____ and ____.
What are cold and dense?
Protogalactic clouds with a high gas density allow for more rapid star formation, and will likely produce ____ galaxies.
What are elliptical galaxies?
Dark matter is "dark" because it does not interact with or emit ____.
What is electromagnetic radiation?
In order to form a ring system, a planet requires many ____ in relatively nearby orbits.
What are moonlets?
The best explanation for the orbital location of Hot Jupiters.
What is migration?
According to general relativity, time runs ____ around a black hole.
What is slower?
We find that more massive ____ correspond to more massive galactic bulges.
What are supermassive black holes?
We cannot describe this era of the Big Bang because we lack a theory that combines quantum mechanics and general relativity.
What is the Planck Era?