A team at Michigan University has based its findings on observations made using an innovative microwave detector which they've developed at Space Physics Research Laboratory in the varsity.
Prof Chris Ruf, who led the team, said that the bolts were dry lightning. "What we saw on Mars was a series of huge and sudden electrical discharges caused by a large dust storm. Clearly, there's no rain associated with electrical discharges on Mars. However, the implied possibilities are exciting," he said.
Electric activity in Martian dust storms has important implications for Mars science, according to the astronomers.
"It affects atmospheric chemistry, habitability and preparations for human exploration. It might have implications for the origin of life even as suggested by experiments in the 1950s," said Prof Nilton Renno, a team member.
In fact, using the kurtosis detector, the astronomers took measurements of microwave emissions from Mars for almost five hours a day for 12 days between 22nd May and 16th June, 2006.
On 8th June, 2006 both an unusual pattern of non-thermal radiation and an intense Martian dust storm occurred, the only time non-thermal radiation was detected. Non-thermal radiation would suggest the presence of lightning.
The team reviewed the data to determine the strength, duration and frequency of the non-thermal activity, as well as the possibility of other sources.
But each test led to the conclusion that the dust storm likely caused dry lightning. This work confirms soil measurements from the Viking landers 30 years ago, and it challenges 2006 experiments that suggested otherwise.
Data from the Viking landers raised the possibility that Martian dust storms might be electrically active like Earth's thunderstorms and thus, might be a source of reactive chemistry. But the hypothesis was untestable.
In 2006, using theoretical modeling, laboratory experiments and field studies on Earth, a group of planetary scientists suggested there's no direct evidence that lightning occurred on Mars. This new research refutes those findings.
"Mars continues to amaze us. Every new look at the planet gives us new insights," said team member Michael Sanders, a Manager of the exploration systems and technology office at Jet Propulsion Laboratory. The findings are to be published in an upcoming issue of 'Geophysical Research Letters' journal. (BJ-01/07)
