'Building blocks of life' found on Mars

The sediments, analysed by the SAM instrument on Curiosity, come from just below the surface, where they have been shielded from most of the UV radiation that would break down organic molecules exposed on the surface.

But National Aeronautics and Space Administration scientists emphasized there could be nonbiological explanations for both discoveries made by the Curiosity rover at a site called Gale crater, leaving the issue of Martian life a tantalizing but unanswered question.

The super exciting part is that the method used to detect these chemicals indicates they're not floating around in the rock all alone, but are smaller pieces of organic chemistry that's been torn off even bigger, more complicated materials.

Scientists hope to further the search for signs of life on Mars with the European and Russian rover, ExoMars, scheduled to land in 2021. What do we stand to gain from these missions anyway?

The space agency has not divulged specific information about what it may have found, leaving many to wonder what intriguing details will be learned about the red planet. For present life, some scientists say we should look below the surface, in soils or in caves, where there might be liquid water still flowing and organic compounds around. Maybe there are subsurface Martian bacteria eating that methane, Tanya Harrison, director of research for Arizona State University's Space Technology and Science ("NewSpace") Initiative, told Gizmodo.

Nasa is now revealing the latest findings of its Curiosity Rover at a press conference.

What they claimed they had discovered was a fossilised micro-organism in a Martian meteorite, which they argued was evidence that there has once been life on the Red Planet. That leaves open the possibility that microorganisms once populated our planetary neighbour and still might. The 2020 rover will include an advanced spectrometer to scan for organic molecules.

Although there is not enough information to know whether the carbon molecules were created by biological or non-biological processes, it is possible that they could be a source of methane, Dr Eigenbrode said. The organic molecules and volatiles, comparable to samples of sedimentary rock rich in organics on Earth, included thiopene, methylthiophenes methanethiol and dimethylsulfide. And the high amount of sulfur in the samples is most likely how they've lasted so long, the researchers said. This mudstone gradually formed billions of years ago from silt that accumulated at the bottom of the ancient lake.

The latest data shows huge swings in the level of methane in the atmosphere as the seasons change, and new types of organic molecules capable of preserving life just beneath its surface.

NASA's Mars Atmosphere and Volatile Evolution Mission (MAVEN) spacecraft effectively ruled out cosmic origins following its analysis of the dust left after a close encounter with the comet Siding Spring in 2014. For example, scientists want to know if it has "Mars quakes".

Knowing that these molecules and compounds were present, then, gives new strength to the idea that life originated or existed on Mars and that more work by the Martian rovers can uncover the past. This is also when life was evolving on our own planet.

The press conference is set to kick off at 2 p.m. EDT today, and while NASA obviously hasn't revealed exactly what it has in store, there's a few things we do know.