Orion is located 1,500 light-years away and is the nearest region of massive star-formation to Earth. Located at the center of the Orion Nebula is a group of four young, massive stars; they are collectively referred to as the "Trapezium" because of the shape they make. The Trapezium is surrounded by a halo of 1,000 faint, low-mass stars similar to the Sun.
Like all massive stars, those in the Trapezium are radiating a stream of energetic X-rays called a stellar wind. However, the wind from the Trapezium is millions of times denser and more energetic than the flow from our own Sun.
When these powerful winds collide with the dense cloud of dust and gas surrounding the stars, they produce shock waves that erode and shape the clouds. Similar to how winds on Earth can sculpt sand dunes in a desert, stellar winds from the Trapezium are carving out a relatively dust and gas free cavity.
Image : NASA ESA M. Robberto STScl and HST Orion Treasury Project Team