Explanation:
If you could watch the night sky for one million years -- how would it change?
Besides local effects caused by the
Earth's spin and the
reorientation of the
Earth's spin axis, the stars themselves will move.
Combining positional data of unprecedented accuracy for two-million stars taken over
years by
ESA's
Earth-orbiting
Hipparcos (now defunct) and
Gaia satellites,
a future extrapolation of star movements was made over millions years.
As shown in the
featured video,
many stars make only small angular adjustments, but some stars
-- typically those nearby -- will zip across the sky.
Once familiar
constellations and
asterisms will become
unrecognizable
as the bright stars that formed them move around.
Not shown are many local nebulas that will surely
dissipate while new ones will likely form in different
places.
Perhaps reassuringly,
future Earth inhabitants will still be able to recognize the
central band of our
Milky Way Galaxy.
