it isn't unlike

I was thinking of putting together some astrophysics flash cards so I can add to what I already know by heart.

How many km in an AU (149,597,870.7km)

How many Earth circumferences in an AU  (Earth circumference: 40075km, 3732.9 in an AU)

How many AU in a light year (63241.1 AU in LY)

How many light years in a parsec. (3.262 LY in parsec)

Actual definitions of AU, Light Year and Parsec (AU - astronomical unit, average distance between Earth and Sun; Light Year - the distance light travels in a year; Parsec - One parsec corresponds to the distance at which the mean radius of the earth's orbit subtends an angle of one second of arc.)

Best understood age of the universe, of our solar system (13.8 billion years, 4.5 billion years)

Closest stars and most visible ones including: Alpha, Beta and Proxima Centauri, Sirius, Arcturus, Vega, Deneb, Altair

The four Galilean moons of Jupiter and for each one a few characteristics of each. (Io, Europa, Ganymede, Callisto) 

The top goldilocks zoned exo-planets as known presently, like the Trappist system.

What is known about Black Holes and Super Massive Black Holes

What is known and not known about dark matter and dark energy.

Rate of expansion of the universe (67.5 km per second per megaparsec)

Earth diameter, moon diameter, distance of moon from Earth at perihelion and aphelion of moon around Earth and Earth around Sun.

Star types, including what is the star type of our sun and of the star list above.