What is ERG project?
In order to reveal the development of space storms and their effects that cause large flux enhancement of the radiation belts, it is essential to observe geospace comprehensively by various observations, so that the ERG project consists of remote sensing from ground-network observations and simulation/integrated analysis in addition to detailed in-situ observation by Arase.
What are the main questions we want to answer?
- The region of outer space near the Earth, known as geospace, is highly variable with time due to interaction between supersonic plasma flow from the Sun (solar wind) and the Earth’s magnetic field. Aurora that is caused by precipitations of electrons and ions into the upper atmosphere is an attractive process occurred in geospace. Faster solar wind speed and intense interplanetary magnetic field result from variations in the solar atmosphere cause a space storm that is a major disturbance of geospace.
- Space weather can impact our way of life as we become increasingly dependent on spacebased infrastructure. Extreme space weather can disable satellites, cause power grid failures, and disrupt GPS services.
- To better understand its role in our space environment. It will unravel the fundamental physics of space, which is dominated by complex electromagnetic interactions unlike what we experience day-to-day on Earth. By studying this space environment close to home, we can better understand the nature of space throughout the universe.
- The Sun continually streams out a solar wind consisting of charged particles, or plasma, travelling at high speeds throughout interplanetary space, as known as the solar wind.
- The planetary magnetosphere is the outermost magnetic barrier for prevention from the solar wind plasma penetrating into the planetary atmosphere,
- The Van Allen radiation belts are two donut-shaped regions encircling Earth where high-energy particles are trapped by Earth’s magnetic field. Sometimes after a solar storm, the number of particles can increase dramatically, and their speeds can become close to the speed of light. This can be extremely dangerous for our technology in this region as well as for astronauts working there. Other times after similar space weather events, the particles decrease in number and speed, and sometimes conditions seem to stay the same.
- The term "magnetic storm," meaning a world-wide magnetic disturbance caused by a disturbance of a solar wind.
- Since space radiation (high energy charged particle) in geospace causes malfunction of on-board computers of satellite and anomaly through surface and deep di-electric charging and causes exposure of astronauts, study of the radiation belts is one of the most important subjects of space weather research to understand and forecast variations of the space environment.
Scientists and engineers from many universities and organizations have come together as a team to make this mission a success. More information can be found about the spacecraft, the instruments, and the teams of people that work on the mission on the websites.