The methanimine and hydrogen cyanide -- two ingredients that build life-forming amino acids -- were found in the galaxy Arp 220, some 250 million light-years from Earth.

The molecules were found by searching radio emissions at specific frequencies. Each chemical substance has a unique radio frequency and astronomers can use that to identify substances.

Robert Minchin, an Arecibo astronomer said methanimine and hydrogen cyanide, when combined with water, form glycine -- the simplest amino acid and a building block of life on Earth.

The astronomers, led by Christopher Salter, announced the discovery Friday in Austin, Texas, during a meeting of the American Astronomical Society.

The Arecibo Observatory is managed by Cornell University for the National Science Foundation.