The Sun is the Star of the Show
Sorry Brian (Cox) you’ve been usurped as star… by an actual star.
Beneath the searing hot raging atmosphere of our Sun lies a turbulent surface, holding mysteries we are yet to comprehend. But, over the next few years we might start finding out some answers to how the lifeblood of our solar system works.
While winter has definitely hit, the rains in Australia are nothing compared to those on the Sun where it rains searing hot plasma. Raindrops the size of countries hurtle to the surface at 200,000 km/h.
There are even violent tornadoes reaching from the surface far into the atmosphere.
It might be these tornadoes which are the reason for one of the biggest mysteries of the Sun. Normally, the further you move from a heat source, the cooler it is – as you might know from a hot light or candle.
However on the Sun, the Corona is around 300 times hotter than the surface, a paradox that has intrigued scientists for years. One potential explanation for this might be those solar tornadoes, could they transport heat upwards into the upper reaches of the atmosphere?
Image Credit: ABC Television
Julia (Zemiro) travelled to NASA’s Goddard Space Flight Center to see one of NASA’s most ambitious missions, which could find the answers to some of these mysteries.
The Parker Solar Probe will orbit ridiculously close to the Sun, at its closest 6 million kilometres – close by Sun standards and closer than any probe before. In its 7 years above the surface, it will investigate the magnetic field of the Sun, teasing out what causes the charged particles and magnetic fields to dance and twist. This will hopefully give us insight into why the corona is so much hotter than the surface, and what causes the solar wind and its acceleration to monumental speeds as it leaves the sun.
Our Sun is big, but small
We might think our Sun is big, but Brian (Cox) blew our minds with how truly small it is.
While 100 Earths would fit across its diameter and it would need 1 million Earths to fill its volume, our Sun is a mere pipsqueak next to the largest star we know of.
By sheer physical size, UY Scuti is the giant of the cosmos. It might only be 30 times the Sun’s mass, but its diameter is 1700 times that of our Sun – around 2.4 billion kilometres across. While Julia held a tiny model Sun between her fingers, a scale model UY Scuti would have filled the telescope dome.
Closer to home is another red giant star – Betelgeuse in the constellation of Orion. But even that is only half the size of UY Scuti. However, Betelgeuse’s size is famously variable, fluctuating between 550 to 920 times our Sun’s diameter.
Our Sun isn’t the smallest though. While it might not compete with the red giants of Betelgeuse and UY Scuti, it isn’t the little kid on the block. The smallest stars are neutron stars, the leftover remnants of a star which has died and exploded in a supernova.
Neutron stars are incredibly dense, pulled together by huge gravitational forces, and are typically about the size of a city – about 30km across.