The image you see below is a star called LL Ori. The photo shows the star moving through the Orion Nebula, and the bow shaped line you see is actually the shockwave the sun creates due in part to its speed. Scientists have long believed all stars create this bow shock, but for our own sun that no longer seems to be the case.
The Interstellar Boundary Explorer satellite in orbit around Earth is used to measure the speed of interstellar particles that enter our solar system. Using data gathered by that satellite scientists have created a computer model that shows our sun is moving at about 52,000 miles an hour. That number is about 7000 mph slower than previously believed. The discovery that our sun is slower than previously believed has led scientists to consider that our sun may not have a bow shock.
The scientists say that the new finding indicates the Helio sphere surrounding our solar system may be stronger than previously believed. The bow shock has always been believed to be a major structural component of our galaxy that has to do with the control of high-energy cosmic ray influx into our solar system. One scientists says that he was "literally shocked" to discover the bow shock was missing from our solar system.
"All the solar system models and theories included a bow shock," said study leader David McComas of the Southwest Research Institute in San Antonio, Texas.
"Having learned for nearly three decades about it, I was literally shocked when we found it was missing."
[via National Geographic]