NASA's STEREO
spacecraft is
designed to take
images of the Sun,
but here it’s being
photobombed by
comet
PanSTARRS.
These images
were taken in
March 2013
by one of
STEREO’s
onboard
instruments
that watches for
coronal mass
ejections —
powerful
explosions of
magnetized
plasma from the
Sun —
as they travel
toward Earth.
In this image,
we see bursts of
light on the left
representing solar
material erupting
off the Sun.
On the right,
Earth appears as
a bright, unmoving
orb.
Then — boom!
Straight through
the middle
comet
PanSTARRS
makes its
appearance.
From STEREO’s
point of view
it looks like the
comet narrowly
escapes the
explosion on the
left, but because
there's no change
in the comet’s tail,
we know the
comet is farther
away from the Sun
than it appears.
So why is this
photobomb
truly out of this
world?
Because the
PanSTARRS
comet won’t be
seen again for
over 100,000
years.