Sternberg is part of the Alpha program for gifted high school students in Israel and is in Australia to talk about her discovery.
Antibiotics are usually used to treat anthrax, but certain bacteria are building resistance.
Sternberg has been looking at bacteria-killing viruses called phages, and she found one that can kill anthrax.
"It was wonderful, I was really, really happy. I was literally jumping up and down, it was amazing," she said.
"Anthrax is a very dangerous disease. It could cause death within a week or less."
It's a significant discovery and a remarkable one for someone of her age.
Sternberg addressed Year 11 students at Emanuel College in Sydney on Tuesday - and has a new fan in the shool's principal.
"When you see people like Sarit and the work she's doing to solve some of the problems the world has, it gives me great hope for the next generation," Emanuel School Principal Anne Hastings said.
As well as studying at high school, Sternberg does scientific research at the Hebrew University of Jerusalem two days a week.
Professor Menahem Ben-Sasson is also in Australia to talk about the university's work and the Alpha program.
"Israel is a start-up nation," Professor Ben-Sasson said.
"And we are the start-up, of the start-up nation."
Sternberg, who will soon head back to Israel to continue studying, says her age is often a scientific advantage.
"Knowing almost nothing, we don't go through whatever everyone else did," she said.
"We go through new ways and new things. I think that's wonderful, I think that's great."