How Astrophysicists Hope To Turn the Entire Moon Into a Cosmic Ray Detector

One of the great mysteries in astrophysics surrounds the origin of ultra-high energy cosmic rays, which can have energies of 10^20 electron volts and beyond. To put that in context, that’s a single proton with the same energy as a baseball flying at 100 kilometers per hour. Nobody knows where ultra-high energy cosmic rays come from or how they get their enormous energies. That’s largely because they are so rare—physicists detect them on Earth at a rate of less than one particle per square kilometer per century.

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CrazyNeutrino said:

How Astrophysicists Hope To Turn the Entire Moon Into a Cosmic Ray Detector

One of the great mysteries in astrophysics surrounds the origin of ultra-high energy cosmic rays, which can have energies of 10^20 electron volts and beyond. To put that in context, that’s a single proton with the same energy as a baseball flying at 100 kilometers per hour. Nobody knows where ultra-high energy cosmic rays come from or how they get their enormous energies. That’s largely because they are so rare—physicists detect them on Earth at a rate of less than one particle per square kilometer per century.

more…

main story here

proton with the same energy as a baseball flying at 100 kilometers per hour.

if one of these hit you in the head it would kill you,have there been any strange deaths where this is a pissabolity?

they don’t reach the earth’s surface, usually. if you were up a high mountain then there might be a possibility. i guess it would have the same kind of odds as being hit with a meteorite.

bob(from black rock) said:

CrazyNeutrino said:

How Astrophysicists Hope To Turn the Entire Moon Into a Cosmic Ray Detector

One of the great mysteries in astrophysics surrounds the origin of ultra-high energy cosmic rays, which can have energies of 10^20 electron volts and beyond. To put that in context, that’s a single proton with the same energy as a baseball flying at 100 kilometers per hour. Nobody knows where ultra-high energy cosmic rays come from or how they get their enormous energies. That’s largely because they are so rare—physicists detect them on Earth at a rate of less than one particle per square kilometer per century.

more…

main story here

proton with the same energy as a baseball flying at 100 kilometers per hour.

if one of these hit you in the head it would kill you,have there been any strange deaths where this is a pissabolity?

Perhaps they are from supernova explosions, don’t they explode on average once every 100 years or so

> if one of these hit you in the head it would kill you,have there been any strange deaths where this is a pissabolity?

As Boris said, they split up on smashing into the Earth’s atmosphere long before reaching the surface. The result is a cosmic ray shower.

Luckily, they’re sufficiently rare that the chance of killing an astronaut is small. People who design outer-space colonies such as a a Moon Base take these things very seriously. It’d be an interesting mathematical exercise to see how lethal the result would be for a space base on Mars, which has a thinner atmosphere.

Would it be impossible for a meteorite to hit the surface of Venus?

Divine Angel said:

Would it be impossible for a meteorite to hit the surface of Venus?

Not if it were big enough

How big is “big enough”?

Divine Angel said:

How big is “big enough”?

depends on how fast it’s traveling

> So where does the Moon come into all this? … The rapid acceleration and deceleration of charged particles produces radio waves. … ultrahigh energy cosmic rays should smash into the lunar surface generating a cascade of other particles and a short burst of radio waves less than a nanosecond long. … astronomers will only be able to see the radio pulses from ultrahigh energy cosmic rays that graze the edge of the Moon coming our way. … Square Kilometre Array, which will be built in South Africa and Australia

OK. So, another use for the SKA.

I also note that on smashing into the moon there will be a shower of particles of lesser energy, some of which will hit the Earth. So it makes sense to look using the Pierre Auger and similar cosmic ray detectors for particles, not necessarily of high energy, coming from the Moon. A correlation between different gamma ray observatories that isn’t associated with sunspots would be a dead giveaway.

diddly-squat said:

Divine Angel said:

How big is “big enough”?

depends on how fast it’s traveling

Faster than a speeding bullet.

There are plenty of impact craters on Venus caused by…impacts. Here are some from the Venus Impact Crater Database:

Luckily, they’re sufficiently rare that the chance of killing an astronaut is small.

Cosmic ray visual phenomena, also referred to as phosphenes or “light flashes”, are spontaneous flashes of light visually perceived by astronauts outside the magnetosphere of the Earth, such as during the Apollo program. Researchers believe that cosmic rays are responsible for these flashes of light, though the exact mechanism is unknown. Hypotheses include one or all of: Cherenkov radiation created as the cosmic ray particles pass through the vitreous humor of the astronauts’ eyes, direct interaction with the optic nerve, or direct interaction with visual centres in the brain

http://en.wikipedia.org/wiki/Cosmic_ray_visual_phenomena

Just use lots of people as cosmic ray detectors