On Thursday, a team of researchers issued a report saying that the plumes of methane that surfaced on Mars in early 2003 had their origins in three specific regions in the planet’s northern hemisphere, where at that time, it was midsummer.

The scientists said that the gas had come out at a speed of 0.6 kilograms a second, while the plume contained 19,000 metric tons of methane.

The leader of the team of researchers, Michael J. Mumma of the NASA Goddard Space Flight Center in Greenbelt, Maryland, stated that the scientists' findings were the first definitive detection of methane on Mars and also the first definitive identification of the active areas that released the gas.

The team’s findings were published online Thursday by the journal Science, while Mumma revealed that several other papers looking into other time-frames of the observations were in the works.

At the time when the presence of methane was reported in 2004 by three teams of scientists, few explanations for the gas release seemed possible. The first of them was geothermal chemical reactions involving water and heat in volcanoes or underground hot springs, but this explanation was unlikely because volcanoes also release sulfur dioxide, among other gases, which was not present in Mars’ atmosphere.

Another possible cause for the plumes of methane appeared to have been a class of bacteria known as methanogens that give out methane as a waste product.

Dr. Mumma’s team used telescopes in Hawaii in order to observe the light reflected off the planet and reported that they had seen black lines in the spectrum corresponding to methane and to water vapor.

The areas that registered the densest wavelengths of light concentrations back in 2003 were Terra Sabae, Nili Fossae and Syrtis Major, the scientists having revealed that these regions’ surface mineralogy suggested that they had had flowing water somewhere in the very distant Martian past.