Solar Probe Plus is part of NASA's Living With a Star program, a series of missions designed to gather critical information about the Sun and its effects on Earth, human activities, even other planetary systems.
We live in the extended atmosphere of the Sun, an active star. While sunlight enables and sustains life, the Sun's variability produces streams of low- and high-energy particles and radiation that can adversely affect life.
Under the protective shield of our magnetic field and atmosphere, Earth is an island in the solar system where life has developed and flourished. The fate of life on Earth is intimately connected to the way our planet responds to the Sun's variations. Understanding the changing Sun and its effects on life and society is a key area of study. Living With a Star addresses the effects of the Sun's highly variable radiation and particle emissions on Earth.
We're all familiar with changing weather on Earth, but how many of us know "weather" also occurs in space? Just as it drives weather on Earth, the Sun is responsible for disturbances in our space environment.
Besides emitting a continuous stream of plasma called the solar wind, the Sun periodically blasts out billions of tons of matter in what are called coronal mass ejections. These immense clouds of material, when directed toward Earth, can cause large magnetic storms in our magnetosphere and upper atmosphere.
The term "space weather" generally refers to conditions on the Sun, in the solar wind, and within Earth's magnetosphere and upper atmosphere that not only can influence the performance and reliability of technologies on the ground and in space, but can endanger human health or even life.
Living With a Star missions are addressing these crucial aspects of the relationship between Sun and Earth.
The missions include the Solar Dynamics Observatory, which is studying the solar atmosphere on small scales of space and time and in many wavelengths simultaneously; and the Van Allen Probes, which are providing unprecedented insight into the physical dynamics of Earth's radiation belts.