A
planetary
system
anchored
by
a
white
dwarf
star,
located
approximately
4,000
light-years
away,
provides
astronomers
with
insights
into
what
could
happen
to
our
Sun
and
Earth
in
about
8
billion
years.
This
scenario
unfolds
if
the
Earth
survives
the
Sun’s
transformation
into
a
red
giant,
expected
to
occur
in
5
to
6
billion
years.
During
this
phase,
the
Sun
will
expand,
potentially
engulfing
Mercury,
Venus,
and
possibly
Earth
before
shrinking
into
a
white
dwarf.
The
Potential
for
Earth’s
Survival
One
scenario
for
Earth’s
survival
involves
its
migration
to
an
orbit
similar
to
Mars
or
beyond,
resulting
in
a
radiation-battered
yet
frozen
world
orbiting
a
burnt-out
star,
as
per
a
study
published
in
the
journal
Nature
Astronomy.
The
newly
discovered
system
reveals
a
white
dwarf
with
half
the
mass
of
the
Sun
and
an
Earth-sized
planet
in
a
wider
orbit,
showcasing
what
a
surviving
Earth
might
resemble.
Keming
Zhang,
a
researcher
from
the
University
of
California,
San
Diego,
highlighted
that
there
is
no
consensus
on
whether
Earth
could
escape
being
swallowed
by
the
red
giant
Sun.
This
system
stands
out
because
it
also
contains
a
massive
companion,
likely
a
brown
dwarf,
which
is
a
stellar
body
that
fails
to
ignite
nuclear
fusion.
The
Discovery
Process
The
planetary
system
was
identified
through
a
microlensing
event,
where
the
gravitational
influence
of
a
body
distorts
the
light
from
a
more
distant
source.
Observations
of
this
event,
dubbed
KMT-2020-BLG-0414,
were
conducted
using
the
Korea
Microlensing
Telescope
Network.
The
investigation
continued
with
the
Keck
telescopes
in
Hawaii,
ultimately
confirming
the
nature
of
the
central
star
as
a
white
dwarf
based
on
the
absence
of
light
expected
from
a
main
sequence
star.
Future
Habitable
Possibilities
While
this
discovery
suggests
that
Earth
could
escape
destruction,
it
raises
questions
about
the
potential
for
life
to
persist
on
our
planet.
Jessica
Lu,
an
astronomer
at
UC
Berkeley,
noted
that
while
Earth
may
avoid
being
engulfed,
it
might
not
remain
habitable
during
the
Sun’s
red
giant
phase.
The
habitable
zone
will
shift
beyond
Earth’s
orbit,
with
Zhang
suggesting
that
humanity
might
need
to
consider
migrating
to
the
moons
of
Jupiter
or
Saturn,
which
could
become
viable
ocean
worlds
as
the
Sun
expands.
Conclusion
This
research
illustrates
the
significance
of
microlensing
in
exploring
planetary
systems.
The
upcoming
Nancy
Grace
Roman
Telescope,
set
for
launch
in
2027,
is
expected
to
enhance
our
ability
to
discover
and
study
exoplanets,
potentially
unveiling
more
unique
configurations
in
the
cosmos.