The detection of lightning on Mars will enrich astrophysics with precious knowledge // Photo: universemagazine.com
Researchers have studied more than 108,000 records of the previously lost American orbiting probe “Maven” and for the first time received proof that there are lightning bolts on Mars. The results of their observations the scientists have shared with readers of the journal Science.
Contrary to popular belief
Whistling atmospherics, also called whistlers, come from lightning strikes and travel along the planet’s magnetic field lines. Their sound is much like the whistling produced by some birds. Such signals are recorded when observing Earth, Jupiter, Saturn, and Neptune, planets that have strong global magnetic fields.
Mars does not have a global magnetic field, and therefore scientists have not previously been able to detect traces of lightning there. Although experiments in laboratory conditions and computer modeling showed that lightning discharges can occur in the conditions of existence on the planet dust storms. For example, as on Earth during dust whirlwinds or volcanic eruptions.
If the atmosphere is in the right state, this process generates electrical discharges. Despite the absence of a global magnetic field, localized magnetic areas in the crust remain on the surface of Mars. They are stronger in the southern hemisphere of the planet than in the northern hemisphere. Waves from electrical discharges during storms can travel along these lines. This observation allowed to refute the established opinion that lightning on Mars can not be.
A cherished signal
In a huge data set, the research team managed to find only one matching wave in the ionosphere of Mars. The signal lasts only 0.4 seconds at a frequency below 110 Hz. The scientists confirmed that the radio wave could have traveled from the planet’s surface to the space probe, but have not yet established the location and cause of the discharge. By its characteristics, the signal is completely identical to radio waves emanating from lightning on Earth.
Lightning happens, but rarely
The authors of the study concluded that lightning discharges on Mars occur, but the special properties of the atmosphere prevent the appearance of radio waves. Electric discharges are quite rare and weak, and there are no prerequisites for their intensification.
The obtained data allow scientists to take a new look at the climate of the “red planet”. Henceforth it will be possible to more thoroughly plan new missions to Mars, and also serve as an excellent example of the fact that many previously obtained in the study of the atmospheres of other planets knowledge unreasonably taken as axiomatic truths.
