30.4.09
The Sun Approaching Solar Maximum
Helium gas caught in the sun's atmosphere may be responsible for the enormous solar explosions known as Coronal Mass Ejections (CMEs). Scientist from the Loas Alamos National Lab, used NASA's Wind spacecraft to make over 2.5 million measurements of the Sun over a decade of observation. It is believe that heliumgas builds up in the solar atmosphere, the corona. yet the solar wind, a constant stream of charged particles emanating from the sun isn't strong enough to completely eject the helium into space so it gradually accumulates until it is violently thrown off in a spectacular CME.
The Solar-Observing SOHO spacecraft.
The discovery of oscillations in the Sun provides a way to study the Sun's insides.
Image: SMM (IAC)
CMEs are some of the most violent and powerfull explosions on the Sun and, although they are not well understood, they seem to greatly affect solar wind speeds. Observations of these explosions show that the amounts of helium present in their ejections are around 5-10 times the abundances seen in the normal solar wind that is expelled continuously from the Sun.
But, scientist don't yet understand a most basic aspect of the solar wind: how exactly does material in the solar corona accelarate to the solar wind speeds of between 960,000 and 1.6 million kilometres per hour???
Scientists are also uncovering more about the very centre of the Sun after 30 years searching for elusive oscillations deep within the Sun. Now, new observations with the Global Oscillation at Low Frequency (GOLF) instrument in the Solar and Heliospheric Observatory (SOHO) may ahve detected the "telltale" ripples created by collisions between dense gas and gaseous material falling deeper into the Sun. These ripples, known as "g-modes", can tell us a great deal about the solar interior and the Sun's core. Also imprinted on these oscillations is information about the conditions in which the Sun formed and the rotation of the ancient cloud of gas that spawned it.
Below are series pix of the Sun's, from the Solar and Heliospheric Observatory (SOHO), Extreme Ultraviolet Imaging Telescope. Thanks to my great buddy, Ezza from space agency, for sharing this superb pics with me...
But, scientist don't yet understand a most basic aspect of the solar wind: how exactly does material in the solar corona accelarate to the solar wind speeds of between 960,000 and 1.6 million kilometres per hour???
Scientists are also uncovering more about the very centre of the Sun after 30 years searching for elusive oscillations deep within the Sun. Now, new observations with the Global Oscillation at Low Frequency (GOLF) instrument in the Solar and Heliospheric Observatory (SOHO) may ahve detected the "telltale" ripples created by collisions between dense gas and gaseous material falling deeper into the Sun. These ripples, known as "g-modes", can tell us a great deal about the solar interior and the Sun's core. Also imprinted on these oscillations is information about the conditions in which the Sun formed and the rotation of the ancient cloud of gas that spawned it.
Below are series pix of the Sun's, from the Solar and Heliospheric Observatory (SOHO), Extreme Ultraviolet Imaging Telescope. Thanks to my great buddy, Ezza from space agency, for sharing this superb pics with me...
The Sun in early 1990s
Image: SOHO - Extreme Ultraviolet Imaging Telescope
Image of the Sun in summer 2000
Image: SOHO - Extreme Ultraviolet Imaging Telescope
Image of the Sun in January 2009
Image: SOHO - Extreme Ultraviolet Imaging Telescope
The Sun's activities are so active...and will be more active within this few years. It is belive that the Sun will reach it solar activity in the year 2012, causing a huge magnetic storm in a history of mankind.
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