The question of whether or not magnets work in space is an interesting one. Some people claim that the earth is not magnetic and that the’magnetic field’ is weak in outer space. However, if you look at the earth and compare it to the moon, you will find that the moon is very much a magnet. Also, animals and plants have evolved to be able to sense the magnetism of the earth. And, there are a number of superconducting magnets that are used in NASA space exploration.
AMS
If you’ve watched space shuttles for any length of time, you’ve probably seen the Alpha Magnetic Spectrometer (AMS). It’s an instrument that measures the energy of cosmic rays. The experiment was designed to last for three years on the International Space Station, but it’s already lasted more than double that time.
AMS is a complex suite of detectors that measure the mass, velocity, and direction of particles as they pass through. Scientists back on Earth can use this information to better understand the particles that travel through space. Some have even suggested that positrons, the anti-matter counterparts of electrons, could be produced by dark matter particles colliding in space.
Since launching on space shuttle Endeavour in May 2011, AMS has measured nearly 148 billion cosmic rays. The AMS team has been working to determine the origins of these rays.
The AMS is composed of a large magnet that warps the path of cosmic rays. The magnet is accompanied by eight detectors that measure the particle’s speed, direction, and charge.
Initially, the AMS was slated to operate until 2014. However, the cooling system of one of the tracking detectors broke down. This threatened to cut short the experiment’s research. Luckily, NASA astronauts were able to fix the problem. After replacing the pump, the internal cooling system should continue collecting data until at least 2030.
AMS is operated by a consortium of scientists from 16 countries. Professor Samuel Ting of the Massachusetts Institute of Technology leads the effort. Several members of Congress were instrumental in lobbying for the project.
AMS is one of the most precise instruments of its kind in space. During its first year of operation, the experiment measured 17 billion cosmic-ray events.
It has also detected antiprotons, the heaviest forms of antimatter. These are formed during collisions between cosmic rays. While the exact source of these rays is still unknown, some scientists believe they could be produced by pulsars.
AMS will continue collecting data for the duration of the space station. In addition, the experiment will test increasingly sophisticated guidance techniques.
Ferromagnetism
Ferromagnetism is a property of certain materials. It is the magnetic interaction between two adjacent atoms’ magnetic dipoles. There are three factors that determine ferromagnetism. These are the density of magnetic permeability, the chemical makeup of the material, and its microstructure. The properties of ferromagnetic materials are important in many modern technologies.
Ferromagnetism is the most powerful type of magnetism. This property is found in metals, and a few other substances. In addition to being used as electrical devices, ferromagnetic materials are often used to form permanent magnets. During the past few decades, the use of magnets has played an important role in space exploration. Space explorers believe that the future holds great potential for space exploration with the use of magnets.
Unlike other types of magnetism, ferromagnetism is spontaneously generated. This means that a ferromagnetic material will become magnetized when exposed to a strong external magnetizing field. Eventually, the ferromagnetic compound will split into several domains, which will line up parallel to create a strong magnetic moment. However, some ferromagnetic materials retain this magnetization when the external magnetizing field is removed.
Some materials, like aluminum and steel, do not have a ferromagnetic property. Antiferromagnetic materials, however, can switch to ferromagnetism by applying a strong current.
A ferromagnetic material is an uncharged metal or alloy, usually a metal with a low atomic number. Materials such as iron, nickel, and cobalt are examples of ferromagnetic materials. Their magnetic properties are very high, but they have high hysteresis. They are characterized by extremely thick magnetic field lines.
As a result of ferromagnetism, a ferromagnetic material may have a magnetic flux density (B), or magnetic flux density, that is much higher than its external magnetic field strength. The difference between the two is called the “magnetization intensity,” or M.
If the ferromagnetic part is subjected to a fast oscillating magnetic field, the walls of the pinned domains tend to release. This produces a hysteresis loop, or remanence. Ultimately, a strong magnetic field must be applied to the ferromagnetic part in order to prevent remanence from occurring.
Superconducting magnets
Superconducting magnets are used in many places, including MRI machines, particle accelerators, magnetic separation processes, and magnetic levitation railway systems. While superconductors have been known for decades, the ability to utilize them in space has yet to be explored.
A superconducting space part would need to be shielded from sunlight and thermally insulated from the rest of the ship. It could interfere with the ship’s other functions and be very hot. However, if it is properly designed, a superconducting spacecraft part could minimize the long-term health risk to astronauts.
Superconducting magnets are able to generate extremely intense magnetic fields. They can produce fields up to 20 teslas. The fields can be used to guide and control the movement of spacecraft.
A superconducting spacecraft part may be necessary for interplanetary missions. Although it would need to be cooled to cryogenic temperatures, it could be cheaper to operate. There have been several experiments conducted to test the potential of electromagnetic propulsion.
One possible solution is to use a static magnetic field. Static fields have unique characteristics for deep space. In particular, they have complicated dimensions and length.
Another solution would be to build a superconducting shield in a toroid configuration. This toroid design would be more effective in dealing with Lorenz forces. But, it would also require a large increase in mass. For a limited shield against GCR, this shield could be sufficient.
Another solution is to make the superconducting part of the spacecraft thermally insulated and room temperature. Several institutions around the world have achieved steady fields of over 40 T. These magnets generally are based on YBCO windings.
Finally, one should note that the Earth’s surface magnetic field is too weak to affect the best superconductors. Besides, inert materials must be thick enough to contain primary particles.
With all these considerations in mind, it is important to look at the broader scope of the problem. We must consider the long-term health risks of crew members and their exposure to galactic cosmic rays. If we choose to travel to Mars, there is a significant chance that we will be exposed to a high dose of radiation. That level is higher than what Apollo missions were exposed to.
Animals can sense magnetism
In the late 20th century, scientists found evidence that animals can sense magnetism in space. This was an important step in sensory biology. Since then, scientists have studied magnetoreception. While they haven’t found the answer yet, they’ve uncovered several theories and anatomical structures that may hold the key.
One of the leading hypotheses is that some bacteria can detect magnetic fields. These bacteria use tiny particles, such as magnetite (Fe3O4), to align their bodies along the lines of the Earth’s magnetic field.
Researchers have also studied the magnetic sense of a variety of invertebrates. These organisms have specialized photoreceptors in their eyes that can detect magnetic fields. Several species of cartilaginous fish have been shown to use magnetic fields to navigate.
Other evidence supports the idea that certain animals have internal compasses. Sharks have been found to have electrically conducting canals in their skin and may respond to electric fields induced by magnets.
Scientists have also observed a link between magnetic fields and light. Night-flying thrushes have been observed to recalibrate their magnetic sense when they see the sunset. Birds have also been found to have photoreceptors that can detect a magnetic field.
Another possible explanation is that animals have magnetotactic bacteria in their bodies. This suggests that they can detect and respond to the magnetic field using bacteria that are symbiotic with the animal. The bacteria’s body, meanwhile, can rotate as the magnetic field lines interact with the body.
Some animal species have been found to use a magnetotactic bacterium as a compass. A team of researchers, led by Robert Fitak, University of Central Florida professor, recently published a review of the evidence supporting this hypothesis.
They acknowledge that their hypothesis needs to be replicated. But they believe that it’s plausible. Their findings are based on a number of factors, including the fact that the animals have been studied in lab conditions and that they are able to respond to a magnetic field in the environment.
While the magnetic sense is one of the last major frontiers in sensory biology, biologists and scientists continue to investigate its mechanisms. As more information comes out, we will learn how animals use the field to navigate.