Chapter 5, Exercise 1 , page 93( Ho Hai Nam , 09ece)

 

Solar Wind Theory Confirmed

The solar wind is like any gust on Earth: It carries along a raft of different particles that can interact with each other. Now scientists have shown that a few of the positively charged protons that float like dust in the solar wind transform into hydrogen atoms on the trip to Earth by scavenging an electron. This is the first detection of the predicted flux of hydrogen atoms, which may one day provide early warning of approaching solar storms.

The space between Earth and the sun may look empty, but it's not. The solar wind of charged particles and magnetic fields blows through a fog of primordial dust and neutrally charged atoms created in nearby stars or the uppermost reaches of Earth's atmosphere. Theorists had predicted that about one in 10,000 of the solar wind's protons would snatch an electron from a passing neutral atom to become a neutral hydrogen atom itself. But proof had to wait for a satellite sensitive enough to separate the faint neutral hydrogen breeze from the other particles in the solar wind. Last year the wait ended, when NASA launched the Imager for Magnetopause to Aurora Global Exploration spacecraft, which carries the Low Energy Neutral Atom (LENA) imager.

Now, new results verify the estimated the strength of the neutral hydrogen wind. "The exact number depends on how hard the solar wind is blowing," says LENA team member Thomas Moore of Goddard Space Flight Center in Greenbelt, Maryland, but the team figures that indeed about one in 10,000 protons becomes a hydrogen atom en route to Earth. They report the results in the 15 March issue of Geophysical Research Letters.

Through many years, the solar storm has brought much damage to electrical devices and affect human’s health on earth. It costs tons of money to fix the situation. There has never been an exact way to predict its coming. But, now the Scientists has discovered a new way to provide early warning of an approaching solar storm. The key for this discovery is very simple:  It based on the amount of hydrogen atom outside earth atmosphere.

        In basic, a solar wind is similar to any gust on earth: it carries bunches of different particles that can interact with each other, one of these particles is positively-charges proton. We all know that an ordinary atom consists nucleus (including positive protons and sometimes neutron) and negative electrons and these particles tend to attract each others to form a new atom. There are many particles and neutral atom float freely outer space. Scientists had predicted that about one in 10,000 of the solar wind's protons would snatch an electron from a passing neutral atom to become a neutral hydrogen atom itself   

        So, by counting these amount of neutral hydrogen atom, the scientists now can estimate the strength of the solar wind is blowing, thus , providing early warning of an approaching solar storm.