Hello Space Fans and welcome to Your Sky Tonight,
my name is Tony Darnell from Deep Astronomy
dot space.
Tonight is halloween.
The stars are coming out earlier and the night
air is crisp, making the atmosphere above
our heads steady and calm.
In the early part of the evening, just as
the Sun goes below the western horizon, we
can see the mighty planet Saturn.
The rings are tilted towards us and through
a small telescope you can begin to see, not
only the rings, but some of the moons as well,
among them Enceladus, Mimas, Tethys and Dione.
Also descending in the west in the constellation
Lyra, containing the very bright star Vega
and an interesting remnant of a dead star
known as the Ring Nebula - very fitting for
halloween.
This is a planetary nebula, created when a
red giant star expands and loses its outer
shell, leaving behind a white dwarf stellar
corpse.
Of course, what’s Halloween without the
Moon?
Tonight it is rising in the East just after
sunset, lighting the way for trick or treaters.
It is a waxing gibbous moon, meaning it is
greater than a half moon and each night is
becoming more full as it reach a full moon
on November 3rd.
As the evening progresses, while you’re
eating some of your Halloween candy, look
up towards the east and you may notice some
Halloween Fireballs.
These are the Taurid meteors, a shower of
debris caused by the Earth travelling through
the remains of Comet Encke and while they
won’t produce a lot of meteors tonight,
what does fall through the atmosphere can
be striking.
Also rising in the east, is the Constellation
Perseus, named after the ancient Greek Hero
who slayed Medusa.
This constellation contains the star Algol,
or demon star.
Algol is a three-star system where two of
the three stars eclipse each other.
This causes Algol’s apparent brightness
- that’s how bright it appears to our eyes
- to dip ever so slightly every 2.86 days.
The variability of Algol is believed to have
been known since antiquity and may have been
one of the reasons that Algol had been associated
with the demon-like creature, known as the
Gorgon.
These is also one more dark denizen of the
night sky whirling overhead: mysterious dark
matter.
It makes up 25% of all matter in our universe,
yet it is the most elusive ghoul of all on
this halloween night.
This material, whatever it is, does not interact
with us in any way whatsoever yet it impacts
our universe tremendously.
Galaxies rotate in strange ways because of
dark matter, it affects galaxy formation in
ways we are only able to hint at.
It is pervasive, dark and mysterious.
Because of all the unknown properties of dark
matter, astronomers have labelled halloween,
Dark Matter Day.
As you go out on this night of tricks and
treats, don’t forget to look up and get
one final treat of the evening, the skies
of halloween are the best treat of all.
That’s it for tonight space fans, have a
great halloween and as always, Keep Looking
Up.
