Bowie learned he would be grandfather days before death

Marking one month since Bowie's death, his son, film director Duncan Jones, said Wednesday that he had revealed the news to his father in the form of a Christmas card.

"Due in June. Circle of life. Love you, granddad," Jones wrote on Twitter as he posted the drawing of an in utero fetus.

Bowie died on January 10 from a battle with liver cancer that he had disclosed to few outsiders -- two days after his 69th birthday and the release of his final album, "Blackstar."

Jones, the son of the music icon and his former wife Angie Bowie, is married to the photographer Rodene Ronquillo. The rocker also has a teenage daughter, Lexi, from his marriage to Somali-born supermodel Iman.

Bowie, who was born in London but lived his final years in New York, was one of the most influential artists in rock history and also had a wide impact on theater and fashion.

Bowie pioneered glam rock early in his career and went on to pursue soul, electronica, disco and jazz. READ: New York declares 'David Bowie Day' as final play ends