The ice is a critical target for science and exploration: it affects modern geomorphology, is expected to preserve a record of climate history, influences the planet's habitability, and may be a potential resource for future exploration.
The discovery is particularly exciting for future human exploration of the planet previously renowned for its dry arid landscape.
Researchers broke the news in a journal report published Thursday, revealing the ice sheets they found just below the surface extend about 300 feet down and could explain much about the planet's past climate.
Although ice has always been known to exist on Mars, a better understanding of its depth and location could be vital to future human explorers, said the report in the U.S. journal Science.
The research, using images from a Nasa spacecraft now orbiting the Red Planet, found that there are eight sites that appear to have huge ice deposits on steep slopes.
'Here we have what we think is nearly pure water ice buried just below the surface.
The ice sheets deposits were found at the geological formations with latitudes of around 55 degrees to 58 degrees located in the southern and northern hemisphere. "You don't see a high-tech solution", Byrne added.
"Astronauts could essentially just go there with a bucket and a shovel and get all the water they need", Byrne said. "It's also much closer to places humans would probably land as opposed to the polar caps, which are very inhospitable".
Researchers believe the ice formed relatively recently, because the sites appear smooth on the surface, unpocked by craters that would be formed by celestial debris smashing into the planet over time.
A radar instrument on the MRO previously detected signatures of thick, buried ice across the planet's belly, however, this latest study indicates a greater prevalence of Martian ice.
Mars likely held vast amounts of water in its ancient past, but most of it escaped into space.
In 2016, a NASA study said ice may yield more water per scoop than minerals, which means the H20 could be more hard to access.
Colin Dundas, a geologist at the US Geological Survey in Flagstaff, Arizona, and his co-authors studied the image and discovered the steep cliffs that appeared to be pure ice.