 What is the Sun? A celestial object described by ancients as having one scorched the face of the Earth when it was ignited? The Sun is the giver, the taker, the essential light in the heavens, but do we understand the gigantic furnace in the celestial abode? The Earth is a Eden and we are protected here as long as things stay quiet in our cosmic neighbourhood, but the threat from something capable of damaging our world is all around us, wait till you hear this. Solar Dynamics Observatory is now in its 10th year of solar observations, 10 years of spectacular firsts, observing suspiciously the things our eyes are forbidden to view directly. The Sun may be a prevalent object, essential to our existence, but that still doesn't mean we know what it is, just because we think we do. To understand the Sun's solar cycle is the key to our existence, and the SDO's long data record is particularly useful for studying the Sun's regular activity cycles, which swings between high and low activity every 11 years. During the high points in the cycle, solar activity like solar flares and coronal mass ejections are more common, and all those scientists' understanding of this cycle has improved in the decades and centuries past. SDO's data is helping uncover even more detail such as the dark area capping the northern polar region of the Sun, and that dark area is what's known as a coronal hole, a magnetically open area of the Sun from which high-speed solar winds escape into space, and these high-speed solar wind streams can spark magnificent auroral displays on Earth when they collide with our planet's magnetic field. These images show the Sun in 211 angstrom light, an extreme wavelength of ultraviolet light, and this type of light is invisible to our eyes and is absorbed by Earth's atmosphere, so it can only be seen by instruments in space. Visible here on the lower right of the Sun is a prominence, with its bright arcs traced out by charged particles spiraling along the Sun's magnetic field lines. Coronal loops are often found over sunspots and active regions, which are areas of intense and complex magnetic fields in the Sun, captured in 304 angstroms, an extreme ultraviolet wavelength. The bright flash shown here on the Sun's upper right is a powerful X-class solar flare, and as you can imagine, X-class flares are the most powerful type of solar flares, and these extreme bursts of light and energy can disrupt the part of Earth's atmosphere where GPS and radio signals travel, captured here in 334 angstroms. This view highlights the many active regions dotting the Sun's surface, and active regions are areas of intense and complex magnetic fields on the Sun, linked to sunspots that are prone to erupting with solar flares or explosions of material called coronal mass ejections, and a burst of material ejecting from the Sun is what's known as a coronal mass ejection, and these eruptions of magnetized solar materials can create spaceware effects on Earth when they collide with our planet's magnetosphere or magnetic environment including aurora, satellite disruptions and when extreme, power outages. Evolving coronal loops dance across the limin' disk of the Sun, and just days after these images were taken, the Sun unleashed a powerful X-class solar flare. This type of light shows a cluster of sunspots near the centre of the Sun. Sunspots appear dark because they are relatively cool compared to surrounding materials. A consequence of the way their extremely dense magnetic field prevents heated material from rising to the solar surface. Where it is here is a burst of plasma from the lower right of the Sun, which happened in conjunction with a mid-level solar flare. Do we understand our star? At least we are beginning to develop an understanding, and who knows perhaps the Sun's energy could be harnessed in ways that could see us sail the cosmos. But what do you guys think about this? Comments below, and thank you for watching.