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How Giant Magnets Could Shield Earth from Hazardous Asteroids

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Can Magnets Safeguard Earth from Asteroids?

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Scientists propose a groundbreaking method to alter the course of potentially hazardous asteroids using a giant magnet. This innovative approach, known as non-contact orbital velocity adjustment (NOVA), aims to mitigate the challenges associated with traditional kinetic impactor techniques, which involve colliding a spacecraft with an asteroid to redirect it. However, as of now, this method remains untested, leaving its effectiveness uncertain.

Günther Kletechka from the University of Alaska Fairbanks introduced the NOVA concept at the Lunar and Planetary Science Conference in Texas on March 17th. He focused on the NOVA application for the asteroid 2024 YR4, which was initially thought to be on a collision course with Earth or the Moon in 2032. Fortunately, subsequent observations indicated it would safely pass by.

This asteroid, less than 70 meters in diameter, represents a manageable target for location adjustment. The proposed spacecraft features a large, superconducting magnet that is approximately 20 meters wide, powered by a nuclear fission reactor. A small booster would maintain its orbit around the asteroid, allowing it to stay within 10 to 15 meters of the surface and interact with its iron content.

While a magnet could theoretically deflect a solid iron asteroid, most asteroids consist of smaller fragments held loosely together in what is known as a rubble pile. “It’s a pile of rubble with virtually zero tensile strength, so you can’t push the whole body effectively,” stated Kletechka during his presentation. He cautioned that kinetic impactors could fragment such asteroids, creating debris that may fall to Earth.

In contrast, the NOVA spacecraft would gradually extract pieces from the rubble pile and trap them in a magnetic field at its center. Each collected fragment would increase both the spacecraft’s mass and magnetic field strength, easing the extraction of subsequent pieces. This technique allows the spacecraft to slowly shrink and control the asteroid’s movement.

To delay the trajectory of YR4 effectively, Kletechka estimates that at least 170 days of continuous operation would be essential. Although he believes that this electromagnetic deflection strategy is feasible, he acknowledges significant uncertainties. The precise quantity of iron in 2024 YR4 remains undetermined, although educated guesses suggest it’s adequate. Furthermore, maneuvering a spacecraft so close to an asteroid for extended periods has not been attempted before and poses unique challenges.

“Including this tool in our Earth’s defense arsenal is beneficial, especially since the likelihood of exacerbating the problem is virtually nonexistent,” Kletechka remarked.

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Source: www.newscientist.com

Revolutionary Small Magnet Matches Strength of Large Magnets for the First Time

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Even Small Magnets Can Be Extremely Powerful

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In a groundbreaking development, researchers have designed a magnet small enough to fit in your palm that rivals the strength of the world’s most powerful magnets.

High-performance magnets are crucial in various scientific fields, being utilized in applications ranging from MRI machines and particle accelerators to advanced nuclear fusion research. The strongest magnets available typically use superconductors, which are materials that conduct electricity nearly without loss.

However, most superconducting magnets are sizable. Often, their smaller counterparts share similar dimensions with traditional superconductors. Take for instance Star Wars‘ R2D2; at its largest, it resembles a two-story structure. According to Dr. Alexander Burns from ETH Zurich, Switzerland, his team has engineered a superconducting magnet capable of matching the strength of larger counterparts, yet it’s only 3.1 millimeters in diameter. They achieved this by coiling a thin tape made of a ceramic known as REBCO, which becomes superconducting at cryogenic temperatures, generating a magnetic field when current flows through the coils.

Dr. Burns stated that the team procured REBCO tape from a commercial source, embarking on a rigorous exploration to determine the optimal magnet design, which involved creating and testing over 150 prototypes. “We adopted a ‘fail fast, fail often’ approach in our strategy,” he noted.

Design and Strength Comparison

Eventually, they refined a design using two or four pancake-shaped coils, achieving magnetic field strengths of 38 Tesla and 42 Tesla, respectively. To provide context, conventional refrigerator magnets typically generate fields less than 0.01 Tesla. The most powerful magnets currently in existence generate field strengths of around 45 Tesla, each weighing several tons and consuming up to 30 megawatts of power. In contrast, Burns and his team’s magnet is hand-sized and operates on less than 1 watt.

The ultimate goal for this groundbreaking technology is to enhance nuclear magnetic resonance (NMR), a technique that utilizes magnetic fields to unveil molecular structures, including those of drugs and industrial catalysts. This technology has long been hindered by the large size and cost of traditional magnets, but the research team intends to democratize access to such advanced tools for chemists. Ongoing tests are being conducted to integrate the magnet into NMR setups.

“Historically, achieving magnetic fields exceeding 40 Tesla necessitated massive and costly facilities, making it crucial to utilize superconducting tape to attain similar strengths in a compact device,” stated Dr. Mark Ainslie from King’s College London. “This innovation indicates that ultra-high-field magnets may soon be accessible to a broader range of laboratories.”

Despite these advancements, several challenges remain before widespread adoption. Questions concerning how to maintain uniform magnetic fields and manage the electromagnetic behavior of the coils must be addressed.

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Source: www.newscientist.com

Using small magnets to measure gravity at a quantum level

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All objects, no matter how small, exert gravity.

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A device that can measure the force of gravity on particles lighter than a single grain of pollen could help us understand how gravity works in the quantum world.

Despite being stuck to the ground, gravity is the weakest force known to us. Only very large objects, such as planets and stars, generate enough gravity to be easily measured. Doing the same for a very small object at a fraction of the distance and mass in the quantum realm is also possible because the size of the force is so small, but a nearby larger object could overwhelm the signal. It is very difficult because there is

now hendrik ulbricht and colleagues at the University of Southampton in the UK have developed a new way to measure gravity on a small scale, using tiny neodymium magnets weighing about 0.5 milligrams that are suspended in a magnetic field that opposes Earth's gravity.

Small changes in the magnetic field of a magnet caused by the gravitational influence of nearby objects can be converted into a measure of gravity. The whole thing is cooled to near absolute zero and suspended on a spring system to minimize external forces.

This probe can measure the gravitational pull of objects weighing just a few micrograms. “We can increase the sensitivity and push the study of gravity into a new regime,” Ulbricht says.

He and his team found that a 1-kilogram test mass rotating nearby could measure a force of 30 atton-Newtons on a particle. An atnewton is one billionth of a newton. One limitation is that the test mass must be moving at a suitable velocity to cause gravitational resonance with the magnet. Otherwise, it will not be strong enough to pick up the force.

The next stage of the experiment will reduce the test mass to the same size as the magnetic particles so that gravity can be tested while the particles exhibit quantum effects such as entanglement and superposition. Ulbricht said this would be difficult because with such a small mass, all other parts of the experiment would need to be incredibly precise, such as the exact distance between the two particles. Masu. It may take at least 10 years to reach this stage.

“The fact that they even attempted this measurement is appalling to me,” he says. julian starlingis a UK-based engineer, as it is difficult to separate other gravitational effects from the exploration mass. Professor Starling said that in this experiment, the anti-vibration system appeared to have had a small but significant effect on airborne particles, so researchers need to find ways to minimize the gravitational effects of the anti-vibration system. It states that there is.

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Source: www.newscientist.com