Heliophysics is a term to describe the study of the Sun, its atmosphere or the heliosphere, and the planets within it as a system
. As a result, it encompasses the study of planetary atmospheres and their magnetic environment, or magnetospheres. These environments are important in the study of space weather.
As a society dependent on technology, both in everyday life, and as part of our economic growth, space weather becomes increasingly important. Changes in space weather, either by solar events
or geomagnetic events, can disrupt and even damage power grids and satellite communications. Space weather events can also generate x-rays and gamma-rays, as well as particle radiations, that can jeopardize the lives of astronauts living and working in space.
This visualization tours the regions of near-Earth orbit; the Earth's magnetosphere, sometimes called geospace; the region between the Earth and the Sun; and finally out beyond Pluto, where Voyager 1 and 2 are exploring the boundary between the Sun and the rest of our Milky Way galaxy. Along the way, we see these regions patrolled by a fleet of satellites that make up NASA's Heliophysics Observatory Telescopes. Many of these spacecraft do not take images in the conventional sense but record fields, particle energies and fluxes in situ
. Many of these missions are operated in conjunction with international partners, such as the European Space Agency (ESA) and the Japanese Space Agency (JAXA).
The Earth and distances are to scale. Larger objects are used to represent the satellites and other planets for clarity.
Here are the spacecraft featured in this movie:
- Hinode: Observes the Sun in multiple wavelengths up to x-rays. SVS page
- RHESSI : Observes the Sun in x-rays and gamma-rays. SVS page
- TRACE: Observes the Sun in visible and ultraviolet wavelengths. SVS page
- TIMED: Studies the upper layers (40-110 miles up) of the Earth's atmosphere.
- FAST: Measures particles and fields in regions where aurora form.
- CINDI: Measures interactions of neutral and charged particles in the ionosphere.
- AIM: Images and measures noctilucent clouds. SVS page
- Geotail: Conducts measurements of electrons and ions in the Earth's magnetotail.
- Cluster: This is a group of four satellites which fly in formation to measure how particles and fields in the magnetosphere vary in space and time. SVS page
- THEMIS: This is a fleet of five satellites to study how magnetospheric instabilities produce substorms. SVS page
The L1 point is a Lagrange Point
, a point between the Earth and the Sun where the gravitational pull is approximately equal. Spacecraft can orbit this location for continuous coverage of the Sun.
- SOHO: Studies the Sun with cameras and a multitude of other instruments. SVS page
- ACE: Measures the composition and characteristics of the solar wind.
- Wind: Measures particle flows and fields in the solar wind.
- STEREO-A and B: These two satellites observe the Sun, with imagers and particle detectors, off the Earth-Sun line, providing a 3-D view of solar activity. SVS page
This enhanced, narrated visualization was shown at the SIGGRAPH 2009 Computer Animation Festival in New Orleans, LA in August 2009; an eariler version created for AGU was called NASA's Heliophysics Observatories Study the Sun and Geospace.
- Voyager 1 and 2: These spacecraft conducted the original 'Planetary Grand Tour' of the solar system in the 1970s and 1980s. They have now travelled further than any human-built spacecraft and are still returning measurements of the interplanetary medium. SVS page