"Q" is for Quasar. A quasar is short for quasi-stellar object. Now, I suppose you will want to know what that is. OK, in most young galaxies there is a highly energetic core that may be powered by a huge black hole. These objects emit exceptionally large amounts of energy.
"R" is for Regolith. Regolith refers to that powdery stuff that covers the surface of celestial bodies like here on earth, and the moon, asteroids, and lots of others. Here on earth we call it soil or dirt.
"S" is for Singularity. Singularity is an area wherein space and time are infinitely distorted. That would be a very, very strange place to be, if you could survive being there.
"T" is for Type II Supernova. It is the explosion of a massive star that occurs when its core runs out of fuel. These explosions leave behind a neutron star or a black star.
"U" just has to be for Universe, which is all that exists. . . maybe.
"V" is for the Van Allen radiation belt. The magnetic field of the earth traps protons, Ions, and electrons. These particles form a protective layer and that layer is called the Van Allen radiation belt.
"W" is for White Dwarf. A white dwarf is the dense remains of an intermediate mass star like the sun that has collapsed and is the same size as earth. As sun like stars burn off most of their fuel supply, they don't have enough eternal pressure to offset its gravity and they collapse and explode.
"X" is for X-ray. We all know what X-rays are but do you know what an X ray star is? It is a bright object emitting x-rays as a primary component of its radiation.
"Y" is for yellow dwarf. A yellow dwarf is a star at its stable point in its transformation. Ordinary stars, including our sun are yellow dwarfs.
"Z" is for zodiac. The zodiac is an imaginary belt across the sky. Some people believe that which ever zodiac sign you were born under affects their lives.
OK folks, that finishes up my space alphabet. Wasn't sure that this old man was able to finish that long list, but I did. Now, some of you may think I am slowing up, but that is not all true. Yes, I am at the age where I walk slow but drive fast. Now, you all have a great day, you hear?