NASA's Solar Dynamics Observatory (SDO) has observed 'surfer'' waves just the size of the United States rolling through the atmosphere of the Sun.
The finding may hold clues as to how energy moves through Sun's atmosphere, known as the corona, and help solve an enduring mystery of why the corona is thousands of times hotter than originally expected.
"One of the biggest questions about the solar corona is the heating mechanism," said solar physicist Leon Ofman of NASA''s Goddard Space Flight Center, Greenbelt, Md. and Catholic University, Washington.
"The corona is a thousand times hotter than the sun''s visible surface, but what heats it up is not well-understood. People have suggested that waves like this might cause turbulence which cause heating, but now we have direct evidence of Kelvin-Helmholtz waves," he added.
Ofman and his colleague Barbara Thompson spotted these waves in images taken on April 8, 2010. These were some of the first images caught on camera by the SDO, a solar telescope with outstanding resolution.
"The waves we''re seeing in these images are so small," said Thompson. "But they''re only the size of the United States," she said.
Kelvin-Helmholtz instabilities usually occur when two fluids of different densities or different speeds flow by each other. In the case of the solar atmosphere, which is made of a very hot and electrically charged gas called plasma, the two flows come from an expanse of plasma erupting off the sun''s surface as it passes by plasma that is not erupting.
To confirm this description, the team developed a computer model to see what takes place in the region. Their model showed that these conditions could indeed lead to giant surfing waves rolling through the corona.
Ofman said that despite the fact that Kelvin-Helmholtz instabilities have been spotted in other places, there was no guarantee they''d be spotted in the sun''s corona, which is permeated with magnetic fields.
Seeing the big waves suggests they can cascade down to smaller forms of turbulence too.
Scientists believe that the friction created by turbulence – the simple rolling of material over and around itself – could help add heating energy to the corona.
The team''s results appeared online in Astrophysical Journal Letters on May 19, 2011 and will be published in the journal on June 10.
For first time ever, researchers grow working brain circuitry in a lab setting from stem cells
Current virtual assistants have been described as a step into an era of controlling computers by speaking instead of typing or tapping screens.
Saturn has more than 60 moons, and Cassini has made new discoveries on some of them, which may have conditions suitable for a form of life.
Facebook is looking at creating "silent-speech interfaces" based on sensors that could be worn, and made in quantity.
The arbitration court in Moscow approved the deal which lasts for six years and nine months, Russian news agencies said.
The security improvement was described as being part of a broader effort to rid the leading social network of hoaxes, misinformation and fake news by verifying people's identities.
Last year, Musk announced that Tesla plans to build a new pickup truck, an urban bus, and launch a sharing system of self-driving cars.
Plunging the Cassini spacecraft down over Saturn's moon Enceladus , the space agency was able to capture samples of water plumes erupting from the surface.
Enceladus likely contains environments similar to Earth
Facebook chief Mark Zuckerberg has sought to deflect criticism that the huge social network may have been used to fuel the spread of misinformation that affected the 2016 US presidential race.
The inexpensive technique, which can have broad applications in monitoring and protecting aquatic life, was conducted in the East River, which is actually an inlet, and the Hudson River last year.
The skin sensors currently used to monitor vital signs in babies born prematurely generate false alarms in up to 90 percent of cases, mainly set off by the baby's movement.
Social media platform says government summons for user’s identity was withdrawn
Social media company reveals lengthy list of tips to improve its users’ ability to spot hoaxes
The proceedings, against Apple Pty Limited and its US-based parent Apple Inc, were brought on behalf of 275 consumers.
Late last year, the company reported its first quarterly profit in more than three years, but then slipped back into unprofitability in the following quarter.