Friday, 21 September, 2018

NASA Solves The Mystery Of Jupiter's Lightning

An artist's impression of the lightning storms on Jupiter. Pic NASA  JPL Image An artist's impression of the lightning storms on Jupiter. Pic NASA JPL
Theresa Hayes | 09 June, 2018, 11:59

Artist's concept of lightning in Jupiter's northern hemisphere. Now, after nearly four decades, thanks to findings collected by NASA's Juno spacecraft, astronomers might have received their long-awaited answers.

Since 1979, when the NASA's Voyager 1 spacecraft flew past Jupiter, scientists were in wonder about the origin of Jupiter's lightning, Jovian lightning. That encounter confirmed the existence of the lightning, which had been theorized for years. "Jupiter lightning distribution is inside out relative to Earth", said Dr Brown.

Scientists also measured similar rates of lightning on Jupiter as seen in storms on Earth. In some ways, it is actually the polar opposite. At the point when NASA sent its Voyager 1 rocket on its outing through our Solar System, its flyby of Jupiter uncovered that Jupiter does surely have lightning, however it wasn't delivering similar sorts of radio flags that researchers know about from lightning here on Earth. "Many theories were offered up to explain it, but no one theory could ever get traction as the answer".

Now, for the first time, Brown's team has detected atmospheric radio signals from lightning - called sferics - in the megahertz range, and it's thanks to Juno's suite of new and highly sensitive instruments.

Earth's equator receives much more sunshine than Jupiter's, since its much closer to the Sun, and the warm moist air there is more likely to rise through convection.

"They were recorded in the megahertz as well as gigahertz range, which is what you can find with terrestrial lightning emissions".

"We think the reason we are the only ones who can see it is because Juno is flying closer to the lighting than ever before, and we are searching at a radio frequency that passes easily through Jupiter's ionosphere", she added.

As for why lightning only seems to occur at high latitudes in Jupiter's atmosphere, Brown said it all comes down to the planet's average distance from the Sun, 779 million kilometres (484 million miles). "You can ask anybody who lives in the tropics - this doesn't hold true for our planet", says Brown. On Jupiter, these bolts of lightning flash frequently across the giant's poles, but never over the equator. And unlike Earth, the majority of its heat is derived from within.

The findings could further get elaborated as Juno continues its work around Jupiter. It brought to light many new facts associated with the huge gas world including- the red spot's depth, the 3D imagery of gas underneath the surface of the planet, and the functionality of Jupiter's auroras. The rays that do make it the gas giant, scientists believe, contribute to a stable upper atmosphere that traps warm air rising from the planet itself. Most of the energy in Jupiter's atmosphere is derived from its solid core.

"Lightning on Jupiter can be as frequent as on Earth", stated Ivana Kolmasova from the Czech Academy of Sciences and the leading author of one of the recent studies. The set of over 1,600 signals, was also produced with data gathered from Juno. In another paper related to the findings from Juno, the researchers noted that the spacecraft's Waves instrument detected six times more lightning than Voyager, with as many as four lightning strikes per second, just like the rate observed on Earth.

Juno's Principle investigator from the South West Research Institute, Scott Bolton, revealed in an email that the orbits are longer than expected and that is why the spacecraft needs more time to collect planned scientific measurements.