Re: If a pulsar formed near the earth what would happen to the Earth?

Our current model of a pulsar is that it consists of a rotating neutron
star left over from a supernova.    For a pulsar to form near the earth, we
would have to have a local supernova, which would of course be a doomsday
scenario of far greater concern than the pulsar.

But if, say a pulsar travelling through space passed near the earth there
would be several effects.  First, the high level of radiation which they
emit would impact the upper atmosphere.  The atmosphere itself would,
however, shield us from most of the x-rays and charged particles.  Second,
pulsars have very strong magnetic fields, and the pulsar would definitely
accelerate particles near the earth to create a very powerful radiation
field.  Interplanetary magnetic fields are very complex, but it would no
doubt cause massive geomagnetic storms on Earth.  This would knock out
power grids and possibly allow radiation from space to sneak down to the
surface.  Pulsars also emit powerful radio waves, which would cause
problems with any electrical equipment on earth.  All of these phenomena
would depend strongly on its distance to the Earth and whether or not the
strong emission from the magnetic poles pointed towards us.  If it was
close enough to affect the Earth directly, you might also consider how the
Sun would react.  The presence of a pulsar could cause massive flares and
solar storms, which would in turn affect the Earth.  At the closest range,
we would worry about the gravitation of a pulsar affecting our planet and
the Sun, causing problems with tides and shifting the crust of the Earth. 
Also, if the pulsar was close enough our orbit would shift, possibly
sending us crashing into the pulsar itself.  

In short, we really don't want a pulsar anywhere near here.

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