This is a drawing of the heliosphere.
Click on image for full size
"Helios" is the ancient Greek word for the "sun". The Heliosphere is the entire region of space influenced by the sun. That would include the regions of space which contain the IMF.
The magnetic field of the sun (the IMF) is enormous and is carried throughout space by the solar wind.
The solar wind and the IMF push back the Interstellar magnetic field and plasma of interstellar space. They create a bubble or cavity, within which the sun and planets reside. The boundary between space dominated by the sun and interstellar space is called the heliopause. No one knows just how far away the heliopause, or "edge" of the heliosphere is, but it could be as far away as 100 AU.
The Voyager 1 and Voyager 2 spacecraft have passed the orbit of Pluto. So, they are now exploring the environment of space. Scientists have received signals from both spacecraft that imply that the spacecraft are coming near the heliopause. For the spacecraft to pass beyond the heliosphere, they will first have to pass through a termination shock. They will then enter interstellar space where no spacecraft has ever gone before. It is thought that the Voyager probes will reach the termination shock in 2001-2002 and that they will be completely clear of the heliosphere by ~2008.
Shop Windows to the Universe Science Store!
Our online store
includes issues of NESTA's quarterly journal, The Earth Scientist
, full of classroom activities on different topics in Earth and space science, ranging from seismology
, rocks and minerals
, and Earth system science
You might also be interested in:
IMF stands for Interplanetary Magnetic Field. It is another name for the Sun's magnetic field. The Sun's magnetic field is enormous and is carried by the solar wind. The solar wind and magnetic field are...more
The Voyager program celebrated its 20th anniversary in 1997. Now Voyager is celebrating another milestone! The Voyager 1 and Voyager 2 spacecraft have passed the orbit of Pluto and they are now exploring...more
The ACE (Advanced Compostion Explorer) was launched aboard a Delta II rocket in August 1997. This unique NASA mission will run a minimum of 2 years (with an expected lifetime of over 5 years). This mission...more
COSPIN is one of the instruments onboard the Ulysses spacecraft. COSPIN stands for the COsmic and Solar Particle INvestigation. The COSPIN instrument is actually made up of 5 different sensors: the Dual...more
Until recently, spacecraft have only been able to measure a limited, two-dimensional section of the heliosphere. This is because spacecraft were confined to stay within the plane of the ecliptic (the plane...more
SWOOPS stands for "Solar Wind Observations Over the Poles of the Sun". This Solar Wind Plasma Experiment onboard Ulysses is basically making a map of the interplanetary plasma within the heliosphere (i.e.,...more
What are the "parts" of the Sun? The photosphere, the visible "surface" of the Sun, defines the outermost boundary of the "inside" of the Sun. The three main regions of the...more
The study of space weather is a relatively young science. As such it has many unanswered questions and unsolved mysteries. Although some of our data relevant to space weather, such as sunspot counts, go...more