Page 102 - BBC Sky at Night Beginners Guide to Astronomy - 2017 UK

SHOOTING
OBSERVING
TIPS

If you’re up for a spot of
meteor watching, then you’ll
need a full sky chart to help STARS
you fi nd your way around
the night sky. But here are
a few other tips to make the
task much more enjoyable
and relaxing.
WISHING ON A SHOOTING STAR IS ABOUT TO
GET EASIER. DISCOVER THE SECRETS OF WHAT
THEY ARE AND THE BEST WAYS TO SEE THEM

There you are on holiday, sitting in a bar can be changed by factors such as the planets
overlooking the sea on some Mediterranean island and moons, or even sunlight. So basically, these
after dark. One of your friends puts down their tiny meteoroids can end up anywhere in the Solar
drink and mentions that the stars look so much System. If Earth happens to be nearby, then the
brighter than at home. You all gaze skyward just meteoroids are in trouble.
❯ Get things ready as a particle the size of a grain of sand smashes
beforehand. If you are into Earth’s atmosphere, leaving a bright trail A FLAMING ENTRANCE
recording a shower you’ll across the night sky as it vaporises. There are There’s a general belief that a shooting star is
need pencils, paper, an gasps and wishes are made in honour of caused by a meteoroid travelling fast and hitting
accurate watch and a red
torch so you don’t ruin your witnessing a shooting star. Earth’s atmosphere. But we shouldn’t discount
dark adaptation. Actually, a ‘shooting star’ is just the popular the tremendous speed at which Earth moves
name for this sort of event. Astronomically you’d through space. Our planet’s average orbital speed
❯ Deckchairs or sunloungers call it a meteor and each one that occurs has a is 30km/s, which is an incredible 108,000km/h
are perfect for a spot of great tale to tell. (67,000mph). If you’re a meteoroid hurtling
meteor-gazing as you need Most meteor-making objects come from comets, through space and along comes a whopping
to be comfortable while
observing – but don’t get which are icy, dusty and dirty chunks that orbit planet that hits you at a speed like this, then there
so comfortable that you around the Solar System. The parts of a comet’s are going to be consequences.
fall asleep! track that are close enough to the Sun warm up and These consequences are a fi ne example of how
the ice is evaporated away, while any solid bits that the atmosphere protects us from space debris such
❯ It will probably get cold, were trapped in the ice are as meteoroids. As the sand grain-sized particle
even in summer, so make released into space. enters the atmosphere, the friction generated by
sure you’re wrapped up
warm or at least have extra These small bits of ‘dust’, known as meteoroids, passing through the gases causes it to heat up to
clothes nearby. Sleeping generally follow the comet, but each particle’s orbit the point where vaporisation occurs. The energy
bags are always useful too.

❯ Darker skies are better MAKING METEORS
for observing: try at least to By the time a comet approaches Path of comet Earth’s orbit
have no streetlights in your Earth, the Sun’s heat has
view, and turn off all of your evaporated ice held by
indoor house and outside the comet. Much of
security lights if you’re in the dust then follows
the garden. the comet and, over Earth Sun
PAUL WOOTTON, FRED BRUENJES the better: move away from out along the entire
time, can be spread
❯ The clearer your horizon,
cometary orbit. When
trees or buildings because
Earth intercepts this dusty
the more sky you can see,
path, lots of particles collide
the more meteors you will
with the atmosphere and
be able to see.
102 skyatnightmagazine.com 2012 we see a meteor shower.