David Barts wrote:


Moreover, how exactly are we "entering a part of the galaxy that is
relatively dense"? We're on one of the rotating spiral arms of the
Milky way. We're moving at pretty much the same speed as the rest of
the arm. It's very hard to "enter" a part of the galaxy we're pacing
at the same speed.

Absent any links that actually back up what you're trying to assert, I
find your assertions to be highly questionable.

--
David Barts
Portland, OR

More to come

The solar system is always plowing through interstellar material. The
Sun's giant magnetic field thwarts much of the dust from entering the
solar system. But the magnetic field weakens periodically, on a cycle
that lasts roughly 22-years. The cycle is related to an 11-year cycle of
sunspot activity.

This is the first of the related dust storms that has been seriously
monitored by a spacecraft.

Some day, the influx could get worse. The solar system is plowing toward
the fringes of a galactic cloud known as the G-cloud.

"The time of the entry into the G-cloud is unknown, but is expected to
occur any time in the next 10,000 years," Landgraf said. "There will be
a constant increase [in dust rates], because the G-cloud is more dense
than the local interstellar cloud that is now surrounding our Sun."

http://www.space.com/scienceastronom...rm_030814.html