Pat MeNaughton, age 14, of Los Angeles, Calif., for the questions

What is a meganarsac?

The prefix mago means a thousand, so a magaparsec is a thousand parsecs. The parsec is an astronomical unit used to measure the distances of the stars. The par comes from parallax and the sec comes from second. The parallax is the angle which tells us the distance of a star and the second is a fraction of an arc. A star with a parallax of one second is at a distance of one parsec.

In plain figures a parsec is equal to 19.2 million, million miles. It is also equal to 3,26 light years, The light year is the distance light travels in one year, speeding along at about 186,000 miles a second. It is equal to about 5.88 million, million miles. Our Galaxy is about 100 thousand light years or 30,000 parsecs wade, A megaparsea, a thousand parsecs, would take us one 30th of the distance across our Galaxy.