26 October 2019 | New Scientist | 51Next in the series
1 Model the equinox
2 Find the North Star
and Southern Cross
3 Test your area’s
light pollution
4 Identify the craters
of the moon
5 Orion and Sirius:
how to star-hop
6 Planet spotting: Mars,
Mercury and Uranus
7 Taurus and
the zodiacal
constellations
Star-hop from Orion
into the zodiac
THE coming week is a great
time to look for planets. A new
moon on 28 October means no
moonlight and, with the exception
of Neptune, every planet is visible
at some point in the coming days.
Even distant Uranus, which at
8 pm GMT on 27 October will be a
mere 2.8 billion kilometres away.
Venus is the easiest to find, with
an apparent magnitude of -4.6. In
the magnitude scale, objects with
lower numbers are brighter. It is
close to the sun, so you can find
Venus in the east before sunrise
or in the west after sunset. On
29 October, you should see it below
the crescent moon after sunset.
The following day at the same
time, Mercury (magnitude -2.0)
will be very close to Venus. We will
be returning to Mercury in a few
weeks’ time, however, when it is
at its furthest point from the sun.
The other planets are harder
to find, so it helps to know how
they differ from stars. The first is
that stars twinkle more. Twinkling
happens because light refracts in
different directions as it passes
through Earth’s atmosphere. Stars
are points of light, so they seem to
twinkle more than the light spread
over the disc of a planet.
Another giveaway is position.
Stars stay fixed relative to one
another, but planets move and
can appear in a different place
from one night to the next.
The ancient Greeks called them
wandering stars, planetes asteres,
hence the name planet.
That wandering isn’t random.
Because they orbit in a similar
plane as Earth, from our pointof view planets all follow the path
of the sun, roughly speaking.
Jupiter is fairly bright, glowing
blue-white at -2.7 magnitude.
It will be near the moon on
Thursday, setting in the west at
about 8 pm local time. If you have
binoculars, try to spot the tiny
pinpricks of its moons spread in
a straight line on either side.
Mars’s magnitude varies. At
the moment, it is fairly dim at
around 1.8. It has a reddish glow
and this month appears in the
east/south-east before sunrise.
Saturn (magnitude -0.5) is pale
yellow and this month will set
about 2 hours later than Jupiter in
the southern part of the sky. Theway Saturn’s poles are tilted right
now means it is a good time to see
its rings if you have a telescope.
Even though Uranus is close, it
is very dim: magnitude 5.7. If you
did the light pollution test from
week three, you should know if
it is possible to see it from your
area. On 28 October, it reaches
opposition, meaning it is on the
opposite side of Earth from the
sun, so in theory, it is visible all
night. Uranus rises in the east as
the sun sets, following the sun’s
path and reaching the highest
point in the sky around midnight.
If you are uncertain about what
you can see, try a stargazing app to
confirm whether you were right. ❚Six of the solar system’s planets are visible this coming week.
Abigail Beall explains how to find themPuzzles
Cryptic crossword,
a goblin game and
a quick quiz p52Feedback
An operating system
for the apocalypse:
the week in weird p53Almost the last word
Coordinated running
and fast swimming:
readers respond p54The Q&A
Eugenia Cheng
on chocolate and
abstract maths p56Twisteddoodles
for New Scientist
A cartoonist’s take
on the world p53The back pages
MATT CHAMPLIN/GETTY IMAGESVENUSWhat you need
Binoculars
For next week
You don't need anything
Abigail Beall is a science writer
in Leeds, UK. This series is
based on her book The Art of
Urban Astronomy @abbybeall
Stargazing at home Week 6
A guide to planet-spotting
Stargazing at home online
Projects will be posted online each week at
newscientist.com/maker Email: [email protected]