How many Apollo's went to the moon?

Question

and how many austronauts have landed and walked there?

Van Allen Belt?

Answer 1

5 Apollo missions landed on the moon and 10 men walked on the moon.

Apollo 11 was the first flight to land on the moon. At the time a man was required to stay in orbit in the command module to serve as a communication link and a last ditch rescue option if the LEM failed to take off.

Apollo 17 was the last lunar landing mission of the program, and all of the Apollo missions were successful except for Apollo 1 and Apollo 13. Apollo one burned up on the launch pad killing the three astronauts. It was the first time someone had died in the entire US Manned Space Program. So when the 3 astronauts were able to return on Apollo 13 it was still considered a successful Mission.

Wikipedia: http://en.wikipedia.org/wiki/Apollo_space_program
If you want the names of the astronauts and more information then check out this article.

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The Van Allen Belts (inner and outer) are large areas of radioactive particles. The earth’s magnetic field protects the earth from a lot of radiation from outer space and from the sun’s solar winds. As part of this protection some of these energetic particles are trapped in a magnetic mirror. Both the US and the USSR accused each other of creating the belts with nuclear tests, but the belts probably originally formed soon after the earth cooled and became mostly solid.

These radiation belts can be very harmful to unshielded satellites and somewhat harmful to humans (the radiation is powerful enough to penetrate 1 millimeter of lead). It is theorized that satellites with very long tethers could be used to discharge the particles in the belt, but others think that the belt helps to protect the earth.

They do have an effect on the Aurora Borealis and may even have effect on the lightening generated on our planet. Earth is not the only planet that has such belts, they don’t appear around the sun, but they could be the result of the magnetic fields on other planets. Which means their existence could be a sign of a planet that could support some sort of life.

According to Wikipedia: http://en.wikipedia.org/wiki/Van_Allen_Belt
“The Van Allen Radiation Belt is a torus of energetic charged particles (plasma) around Earth, trapped by Earth's magnetic field. The Van Allen belts are closely related to the polar aurora where particles strike the upper atmosphere and fluoresce.

The large outer radiation belt extends from an altitude of about 5,000–65,000 km and has its greatest intensity between 14,500 and 19,000 km. The outer belt consists mainly of high energy (0.1–10 MeV) electrons trapped by the Earth's magnetosphere. The gyroradii for energetic protons would be large enough to bring them into contact with the Earth's atmosphere. The electrons here have a high flux and at the outer edge (close to the magnetopause), where geomagnetic field lines open into the geomagnetic "tail", fluxes of energetic electrons can drop to the low interplanetary levels within about 100 km (a decrease by a factor of 1000).
There is debate as to whether the outer belt was discovered by the US Explorer IV or the USSR Sputnik II/III.

The inner Van Allen Belt extends from roughly 1.1 to 3.3 Earth radii (4,400 to 13,200 miles), and contains high concentrations of energetic protons with energies exceeding 100 MeV, trapped by the strong (relative to the outer belts) magnetic fields in the region.

It is believed that protons of energies exceeding 50 MeV in the lower belts at lower altitudes are the result of the beta decay of neutrons created by cosmic ray collisions with nuclei of the upper atmosphere. The source of lower energy protons is believed to be proton diffusion due to changes in the magnetic field during geomagnetic storms.

A gap between the inner and outer Van Allen belts is caused by the very low frequency(VLF) waves which scatter particles in pitch angle which results in the loss of particles to the atmosphere. Solar outbursts can pump particles into the gap but they drain again in a matter of days. The radio waves were originally thought to be generated by turbulence in the radiation belts, but recent work by James Green of the NASA Goddard Space Flight Center comparing maps of lightning activity collected by the Micro Lab 1 spacecraft with data on radio waves in the radiation-belt gap from the IMAGE spacecraft suggests that they're actually generated by lightning within Earth's atmosphere”