What Were the Major Findings of the Yohkoh Spacecraft?

Active Region Transient Brightenings

• One of the first discoveries from the Yohkoh spacecraft was that active regions of the sun are not static, but contain flarelike brightening. This is known as active region transient brightening, ARTB. These brightenings are not as intense as flares and are classified as nonthermal, as they produce much less heat when compared to flares. It was found that how often the ARTBs occur is correlated to the amount of X-ray flux in the area and this X-ray flux can be measured using telescopes rather than radio data.

Coronal Mass Eruptions

• A coronal mass eruption occurs when electrically-charged gas erupts from the part of the sun known as the corona. Up to 10 billion tons of gas is released into space. These can be described as a type of space storm and can be very destructive. These gas particles disrupt the magnetic field of the earth and cause satellite malfunctions and power blackouts. The Yohkoh spacecraft identified an S-shape structure, called a sigmoid, that occurs on the surface of the sun before the coronal mass eruption occurs. This early notice can be used by NASA, power companies and telecommunications to take steps to prevent damage or problems.

Solar Flares

• The Yohkoh mission determined the causes of solar flares. These flares occur due to a sudden release of magnetic energy. These particles hit the surface of the sun and cause solar material to surge outwards of the surface, at very high velocities. This was a huge revelation for how the sun works and has set the basis for many new missions and experiments. This is an important discovery in the field of solar physics.

Solar Winds

• Along with observations and sampling done by the Ulysses spacecraft, another major finding of the Yohkoh involved solar winds. Solar wind changes due to explosions on the sun's surface; this also affects the magnetic energy of the sun, earth and space. The spacecraft managed to produce models on solar wind and how to find weak spots in space that may be affected by solar winds, which also correlate to weak magnetic areas. Therefore, additional spacecraft are testing these weak areas to determine the effectiveness of the model.