Italian scientists are hoping to extract Galileo's DNA to determine how the astronomer forged groundbreaking theories on the universe while gradually becoming blind.

Scientists at Florence's Institute and Museum of the History of Science want to exhume the body of 17th Century astronomer Galileo Galilei to find out exactly what he could see through his telescope.

The Italian astronomer championed the heliocentric view of the universe - that earth orbited the sun - first proposed by his Polish predecessor Nicolaus Copernicus.

In 1609, he discovered spots on the Sun, craters and peaks on the surface of the Moon and satellites orbiting Jupiter, thereby confirming Copernicus's theory that planets orbit the Sun rather than the Earth.

Galileo was also known to have a degenerative eye disease that eventually left him blind before his death in 1642.

Institute director, Paolo Galluzzi, hopes the Galileo's DNA will reveal what caused him to become blind.

"If we succeed, thanks to DNA, in understanding how this disease distorted his sight, it could bring about important discoveries for the history of science," Galluzzi says.

"We could explain certain mistakes that Galileo made: why he described the planet Saturn as having 'lateral ears' rather than having seen it encircled by rings for example."

In an effort to recreate what Galileo saw, the scientific team has made an exact replica of his telescope.

They now want DNA proof of what ophthalmologists have said was a genetic eye disease and thereby more fully understand the conditions under which he made observations that revolutionised our understanding of the cosmos.

It will take the team one year to raise the 300,000 euros (A$590,000) needed to finance the project and clear administrative hurdles to open Galileo's tomb in Florence's Santa Croce Basilica, says Galluzzi.

The United Nations has proclaimed 2009 the International Year of Astronomy, marking the 400th anniversary of Galileo's observations.
Remote possibility

Dr Jeremy Austin of the Australian Centre for Ancient DNA at the University of Adelaide believes the method of Galileo's burial will make it difficult to find useful DNA.

"If you put a human corpse in a coffin and seal it inside a slab of granite, which appears what happened to Galileo's body, there is going to be a huge amount of purification and decomposition," he says.

Austin says another challenge for the Italian researchers will be finding nuclear DNA from Galileo's body, which contains the genes responsible for blindness.

"In a lot of cells there is way more mitochondrial DNA than there is DNA in the nucleus," he says. "Therefore mitochondrial DNA survives a lot longer in old and ancient specimens because there are more copies."

"The chances of getting the genes [responsible for eyesight] - of which there are two copies per cell related to eyesight - is very difficult."

by:abc science