Our heliosphere,
this giant bubble
around the Sun and planets,
is like our “house” in space
because it keeps out
the weather
coming from the galaxy
beyond.
We know this because we can
see what happened
when it leaked.
Beyond the walls of our
cosmic “house,”
you’ll find one of the most
dangerous forces in space:
Galactic cosmic rays are
near-light speed particles
that shoot out from
supernovas
and other distant explosions,
and they pelt our heliosphere
from all directions.
But our heliosphere
pushes back.
The Sun’s solar wind
and magnetic fields
act like insulation
around our “house,”
deflecting most of these
dangerous particles away.
Still, some get through,
and we can actually
see the scars
they leave in trees.
When cosmic rays
collide with Earth’s
atmosphere,
they create rare particles
that are eventually
metabolized by trees.
By studying tree rings,
we can identify times
when more cosmic rays
rays reached Earth —
like during a 70-year period
in the 1600s
when solar activity
was unusually low
and the heliosphere
was weaker.
NASA’s IMAP mission
will help us understand
how our weather-proofing
system works,
and how it’s affected
by changes in our Sun.
How studying our heliosphere
can aid in the search
for life elsewhere.