Solar storm from 'canyon-like' hole in the sun could hit Earth as soon as Thursday (Dec. 1)

[Admin]

The hole could beam solar material outwards at speeds up to 1.8 million mph (2.9 million kph)

Solar storm from 'canyon-like' hole in the sun could hit Earth as soon as Thursday (Dec. 1) : Read more

 

[Anonymous Bosch]

Ben, would you please expound a bit on your statement, that earth's mangetosphere is weakest at the poles. The magnetic field itself is strongest at the poles where the field lines are most densely packed. Particles from the solar wind spiral around the field lines. The loops of the spirals are tightest where the field is strongest. That causes more particles to concentrate near the poles where the flourescence they induce in the atmospheric gasses is most pronounced and, therefore, most visible. The effect is often described as the particles "following the field lines." Since more particles interact with the atmosphere at the poles than at lower latitudes, the shield afforded by the Earth's magnetic field is less effective there. In that sense the shield is weakest where the field is strongest.

 

[billslugg]

The author is oversimplfying for the benefit of those not well versed in magnetic theory. Yes, the flux density is greatest at the poles but their orientation of the field lines allows the Sun's charged particles to follow them down to the Earth's upper atmosphere. Charged particle can cross a magnetic field line only by doing work, following them requires no work be done. Unless the impinging particle is exactly aligned with the field lines it will feel a sideways deflection and spiral.

 

[Anonymous Bosch]

Great clarification, Bill; thank you! I had not considered the fields acting as a directional filter.

 

[billslugg]

Such a field is proposed as a funnel to gather protons and electrons from interstellar space as fuel for a fusion engine. There would be a coil of wire oriented in a plane perpendicular to the direction of travel, with the spaceship at the center. Sort of like the Earth tilted on its side. Any charged particle would see the field lines as a funnel, causing it to spiral towards the center where they would all gather together, forcing the atoms closer together. Then they could be collected somehow. There are not many atoms in between stars, only about 10^6 per cubic meter. When you consider a mole of hydrogen, 1 gram, has 6e23 atoms, you have to sweep an very large area to collect a tiny bit of material. The scoop would have to sweep a one meter square 6e17 meters to collect one gram of fuel. It is only 4e16 meters to Proxima Centauri.
Intergalactic space only has one atom per cubic meter.
If a one square meter collecter was sent to the Andromeda galaxy, 2.5 million light years away, it would collect but 40 milligrams of hydrogen. This is why space is so clear.