Origins of the sun's swirling jets revealed - NASA scientists bare all secrets!

Image courtesy: NASA’s Goddard Space Flight Center/Joy Ng, producer

New Delhi: The sun is another world unto itself. Mighty, mystifying and strong, the biggest star in the solar system is as important for the sustenance of life as its wrath is devastating.

NASA's team of scientists have been working tirelessly toward understanding the enigma that is the sun.

Time and again, the US space agency has released videos and images of the luminous body spewing solar material and oozing plasma on its surface, which makes one wonder what other secrets the gigantic ball of fire may be holding.

The sun also emits spicules – wild jets of solar material – bursting from its surface, amounting to 10 million at a pace of 60 miles per second.

The spicules, the origins of which is NASA's latest discovery, can reach lengths of 6,000 miles before collapsing.

Despite their grass-like abundance, scientists didn’t understand how they form. Now, for the first time, a computer simulation — so detailed it took a full year to run — shows how spicules form, helping scientists understand how spicules can break free of the sun’s surface and surge upward so quickly.

The results of this NASA-funded study were published in Science on June 22, 2017 — a special time of the year for the IRIS mission, which celebrates its fourth anniversary in space on June 26.

According to NASA, this work relied upon high-cadence observations from NASA’s Interface Region Imaging Spectrograph, or IRIS, and the Swedish 1-meter Solar Telescope in La Palma, in the Canary Islands. Together, the spacecraft and telescope peer into the lower layers of the sun’s atmosphere, known as the interface region, where spicules form.

In a video released by the US space agency, the origins of the dynamic jets are explained in detail. Have a look!

“Numerical models and observations go hand in hand in our research,” said Bart De Pontieu, an author of the study and IRIS science lead at Lockheed Martin Solar and Astrophysics Laboratory, in Palo Alto, California. “We compare observations and models to figure out how well our models are performing, and to improve the models when we see major discrepancies,” NASA reported.

Since spicules are transient, forming and collapsing over the course of just five to 10 minutes, the tenuous structures are difficult to study from Earth, making it a thorny problem for scientists who want to understand how solar material and energy move through and away from the sun.

The key, the scientists realized, was neutral particles. They were inspired by Earth’s own ionosphere, a region of the upper atmosphere where interactions between neutral and charged particles are responsible for many dynamic processes.

The research team knew that in cooler regions of the sun, such as the interface region, not all gas particles are electrically charged. Some particles are neutral, and neutral particles aren’t subject to magnetic fields like charged particles are. Scientists had based previous models on a fully ionized plasma in order to simplify the problem. Indeed, including the necessary neutral particles was very computationally expensive, and the final model took roughly a year to run on the Pleiades supercomputer located at NASA’s Ames Research Center in Silicon Valley, and which supports hundreds of science and engineering projects for NASA missions, the space agency explained.

With the new model, the simulations at last matched observations from IRIS and the Swedish Solar Telescope; spicules occurred naturally and frequently. The 10 years of work that went into developing this numerical model earned scientists Mats Carlsson and Viggo H. Hansteen, both authors of the study from the University of Oslo in Norway, the 2017 Arctowski Medal from the National Academy of Sciences. Martínez-Sykora led the expansion of the model to include the effects of neutral particles.

“This is a major advance in our understanding of what processes can energize the solar atmosphere, and lays the foundation for investigations with even more detail to determine how big of a role spicules play,” said Adrian Daw, IRIS mission scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “A very nice result on the eve of our launch anniversary.”