This image shows the magnetic field lines of a planet passing by a moon and creating a wake.
Click on image for full size
A moon which is inside a magnetosphere usually travels slower than the magnetic field. This means that the magnetic field lines will pass over the satellite like water going around a rock. Because the moon is made of conducting material, the magnetic field will be delayed in passing around the moon. Thus the field lines will be distorted in passing over the satellite. Eventually they straighten up. The region upstream of the satellite, in the magnetic field of the planet, is called a satellite wake.
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:
AU stands for Astronomical Units. It is a useful way to measure the distances in interplanetary space. It is the distance between the Earth and the Sun, which is about 93 million miles. For reference,...more
The solar wind is formed as the Sun's top layer blows off into space, carrying magnetic fields still attached to the Sun. Gusts form in the solar wind associated with violent events on the Sun. Particles...more
For a planet to be affected by a blob of material being ejected by the sun, the planet must be in the path of the blob, as shown in this picture. The Earth and its magnetosphere are shown in the bottom...more
The aurora we are most familiar with is the polar aurora. This is what people are talking about when they say the northern or southern lights. But there are other less-known aurora, such as SAR arcs....more
This figure shows the effect of the aurora on the atmosphere. When FAC's enter the atmosphere and create the aurora, they heat the atmosphere suddenly and abruptly. This creates an impulse which travels...more
This picture shows the flowing of particles into and out of the auroral zone, as Field-Aligned currents (FAC's) take at short-cut through the atmosphere. Some of the particles entering the auroral zone...more
This figure shows a series of images of the auroral oval as it expands over the course of about an hour in response to a geomagnetic storm. This is an animation of the auroral oval expanding....more