All 5 building blocks of DNA, RNA found in meteorites from Canada, U.S., Australia

A fresh examination of meteorites that landed in the United States, Canada and Australia is bolstering the notion that early in Earth's history, such objects may have delivered chemical ingredients vital for the advent of life.

Scientists had previously detected on these meteorites three of the five chemical components needed to form DNA, the molecule that carries genetic instructions in living organisms, and RNA, the molecule crucial for controlling the actions of genes. Researchers said on Tuesday they have now identified the final two after fine-tuning the way they analyzed the meteorites.

Unlike in previous work, the methods used this time were more sensitive and did not use strong acids or hot liquid to extract the five components, known as nucleobases, according to astrochemist Yasuhiro Oba of Hokkaido University's Institute of Low Temperature Science in Japan, lead author of the study published in the journal Nature Communications.