Alex St. George, age 16, of Dodge City. Kan., for his question

WHO DISCOVERED THE MAFFEI GALAXIES?

The Maffei galaxies, often called Maffei 1 and Maffei 2, are two large star systems. They probably belong to the group of galaxies that includes the earth's galaxy, the Milky Way. They were discovered in 1968 by an Italian astronomer Paolo Maffei, for whom they were named.

The galaxies remained unknown for such a long time because they are hidden by dense clouds of cosmic dust and gas in the earth's galaxy. Maffei photographed them through a telescope by using film sensitive to infrared rays, the invisible heat rays given off by the galaxies. Infrared rays, unlike light rays. can penetrate dust clouds.

In 1971, astronomers at several California observatories determined the approximate size and shape of the Maffei galaxies.

The Maffei galaxies are less than 12 million light years from earth. A light year is the distance that light travels in a year. It equals about 6 trillion miles.

Each of the Maffei galaxies measures from 50,000 to 100,000 light years in diameter. Maffei 1, the brighter of the two systems, may consist of as many as 100 billion stars. Maffei 2 has only about 10 billion stars.