Related Experiment Video
Updated: Jul 25, 2026
07:54
Experimental Methods of Dust Charging and Mobilization on Surfaces with Exposure to Ultraviolet Radiation or Plasmas
Published on: April 3, 2018
Over the southern solar pole: low-energy interplanetary charged particles
L J Lanzerotti1, T P Armstrong, R E Gold
1AT&T Bell Laboratories, Murray Hill, NJ 07974, USA.
Science (New York, N.Y.)
|May 19, 1995
Summary
The heliospheric current sheet significantly shapes the heliosphere, even in polar regions. Interplanetary shocks accelerated electrons far from Ulysses
Area of Science:
- Space physics
- Heliophysics
- Plasma physics
Background:
- The heliosphere's structure is influenced by solar activity and magnetic fields.
- Understanding particle transport in the heliosphere is crucial for space weather prediction.
Purpose of the Study:
- To investigate the influence of the heliospheric current sheet on particle fluxes in the southern polar region.
- To analyze the acceleration mechanisms of low-energy ions and electrons.
Main Methods:
- Utilized data from the Heliosphere Instrument for Spectrum, Composition, and Anisotropy (HISCALE) on the Ulysses spacecraft.
- Analyzed fluxes of low-energy ions and electrons (> 50 keV) during polar crossings.
Main Results:
- The heliospheric current sheet significantly influenced the heliosphere's structure down to -75 degrees heliolatitude.
- Interplanetary reverse shocks accelerated electrons far from the Ulysses spacecraft.
- Anomalous oxygen flux and Ne/O ratios were measured at high heliolatitudes.
Conclusions:
- The heliospheric current sheet plays a dominant role in shaping the heliosphere.
- Particle acceleration is linked to current sheet dynamics and interplanetary shocks.
- Further research is needed to clarify low-energy electron flux enhancements at higher heliolatitudes.
Related Concept Videos
01:10Kepler's First Law of Planetary Motion
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. He formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe.
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
01:22Energy Carried By Electromagnetic Waves
Anyone who has used a microwave oven knows there is energy in electromagnetic waves. Sometimes, this energy is obvious, such as in the summer sun's warmth. At other times, it is subtle, such as the unfelt energy of gamma rays, which can destroy living cells. Electromagnetic waves bring energy into a system through their electric and magnetic fields. These fields can exert forces and move charges in the system and, thus, do work on them. However, there is energy in an electromagnetic wave,...
01:20Momentum And Radiation Pressure
An object absorbing an electromagnetic wave would experience a force in the direction of propagation of the wave. This force occurs because electromagnetic waves contain and transport momentum. The force accounts for the wave's radiation pressure exerted on the object. Maxwell's prediction was confirmed in 1903 by Nichols and Hull by precisely measuring radiation pressures with a torsion balance. The measuring instrument had mirrors suspended from a fiber kept inside a glass container. Nichols...
01:25Magnetic Field due to Moving Charges
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
01:29Potential Due to a Polarized Object
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
01:09Radiation Pressure: Problem Solving
The radiation pressure applied by an electromagnetic wave on a perfectly absorbing surface equals the energy density of the wave. The wave's momentum also gets transferred to the surface when an electromagnetic wave is entirely absorbed by it. The rate at which momentum is transmitted to an absorbing surface perpendicular to the propagation direction equals the force on the surface.
The average value of the rate of momentum transfer divided by the absorbing area represents the average force per...
The average value of the rate of momentum transfer divided by the absorbing area represents the average force per...