Boron, a relatively rare chemical element, has been detected on Mars for the first time. It's a sign there may have been life on the Red Planet.

A paper published in the Geophysical Research Letters on Tuesday links the presence of boron to the possible presence of ribonucleic acid on the unforgiving dust world at one time or another. This acid, better known as RNA, is an essential to building block of life.

RNA is the middleman in between DNA and the production of proteins necessary for cell function. The genetic information of an organism is stored in DNA and translated into RNA via a process called transcription.

Scientists analyzed the data from ChemCam, an instrument aboard NASA's Curiosity rover on Mars that fires lasers to excite the electrons in the chemical elements in Martian soil and rock. This causes light to be emitted at particular frequencies depending on the types of elements present in the sample.

Borates – a class of molecules containing boron – were discovered by the rover in veins of calcium sulfate minerals left over from the groundwater in the Gale Crater.

Patrick Gasda, lead author of the paper and a postdoctoral researcher at Los Alamos National Laboratory, said: "Because borates may play an important role in making RNA – one of the building blocks of life – finding boron on Mars further opens the possibility that life could have once arisen on the planet.

"Borates are one possible bridge from simple organic molecules to RNA. Without RNA, you have no life. The presence of boron tells us that, if organics were present on Mars, these chemical reactions could have occurred."

RNA is unstable. It contains ribose, a simple sugar that degrades easily in water. But the addition of boron in water creates borates that can react with the ribose, keeping it stable enough to form RNA. The detected borates are estimated to be 3.8 billion years old – younger than the formation of life on Earth. "Essentially, this tells us that the conditions from which life could have potentially grown may have existed on ancient Mars, independent from Earth," said Gasda.

The pH levels of the groundwater are thought to range from neutral to alkaline at a temperature between 0‑60°C (32‑140°F), increasing the chances of habitability.

The discovery of boron joins a long list of mounting evidence that the conditions on Mars might have been, once upon a time, promising for microbial life. A series of minerals in Martian clay point to liquid water in the form of a lake in the Gale Crater.

There has been no concrete confirmation that life does or did exist on Mars. But as scientists keep finding possibilities of extraterrestrial life on the Red Planet, it'll remain an interest to space agencies.

NASA, the European Space Agency, and Russia's Roscosmos State Corporation for Space Activities have expressed interest in manned missions to Mars in the 2030s. ®