WELCOME

“Earth was just a hot rock in a lifeless

MEET THIS ISSUE’S EXPERTS

ANDY EXTANCE Andy is a science writer. He

Tiny deer hunter

© Getty Meet the deer ked, a skin

Supercell cyclone

© Getty Tornado Alley is famous for its

Snot science

© Getty The internal lining of the human

Titanium tantrum

© NASA/CXC/RIKEN/T. Sato et al.; NuSTAR: NASA/NuSTAR 11,090

Light from behind a black hole spotted

GLOBAL EYE

CALIFORNIA CHIPMUNKS CONTRAC T THE PLAGUE

Positive results for plague in chipmunks prompted officials

Ignoring climate change will yield “untold suffering”

N early 14,000 scientists have signed a new

Just 1.5 per cent of our genome is ‘uniquely human’

Only a small portion of human DNA is

THE AMAZON CREATES MORE GREENHOUSE GASES THAN IT ABSORBS

Wildfires in the Amazon are polluting the air

Megaripples from dinosaur-killing asteroid are under Louisiana

More evidence has been discovered to denote the

‘Massive melting event’ strikes Greenland

Ice receding from a glacier near Kangerlussuaq, Greenland.

US LIFE EXPEC TANCY HAD A HUGE DECLINE IN 2020

Memorials hang at Greenwood Cemetery to remember and

Water vapour detected on Jupiter’s massive moon

In the wisp-thin sky of Ganymede, the largest

Archaeologists find exiled Anglo-Saxon hermit king’s lair

Until recently, archaeologists thought the cave dated to

Alien abduction stories may come from lucid dreaming

Lucid dreaming, in which people are partially aware

MAN IN CHINA DIES OF RARE ‘MONKEY B’ VIRUS

Macaque monkeys are common carriers of the monkey

WISH LIST

The latest tech for PETS

Does every galaxy have a massive black hole in the centre?

Did you know? M87’s black hole has the

WHY ARE ‘CAT YEARS’ SO MANY HUMAN YEARS?

Humans live much longer than cats, so the

WHAT’S THE DEADLIEST SUBSTANCE TO HUMANS?

Using a measure of toxicity called the median

When did cavemen first paint in caves?

Cavemen often drew the animals around them, like

Who invented food colouring and why?

Perkins’ original stoppered bottle of Mauveine © Getty

DO POLICE PUT CHALK AROUND BODIES AT CRIME SCENES, OR IS THAT JUST IN FILMS?

Although chalk outlines were sometimes used to show

WHY ARE THERE DIFFERENT SHAPES OF CHIMNEY POT?

Chimney pots are designed to extend the smokestack

WHY DON’T EVERGREEN TREES HAVE LEAVES?

Through the canopy of Scots pine evergreen trees

Do all animals have red blood?

A close up of a common octopus in

DOES THE FORCE OF GRAVITY STILL EXIST AT ZERO KELVIN?

There’s no definitive answer to this question, because

Do the outer planets have many more moons than the inner planets because they’re so big?

Yes, that’s right. Their stronger gravity allows them

IF A HUMAN DOESN’T EAT ANY FOOD, HOW LONG CAN THEY LIVE? WHAT ABOUT IF THEY DON’T DRINK WATER?

It’s difficult to know exactly, but one thing

WHY DO ONIONS MAKE YOU CRY?

Onions produce a chemical known as syn-Propanethial-S-oxide, which

Why is bird poop whitish?

The white stuff that you find splattered all

Are sea slugs related to land slugs?

Did you know? Most land and sea slugs

Do sea plants photosynthesise?

Yes, they do. Plants in the sea, like

What are the highest and lowest instruments?

If you unfolded a contrabassoon, it would be

Do goldfish really have a threesecond memory?

The striking orange colours of the unmistakable goldfish

THE LIBRARY

The latest book releases for curious minds

MAKE A BUG CATCHER

Use this tool to suck garden critters up and observe them closely

DOXFORD’S ENGINES

Dear HIW, I’ve just picked up your magazine

TRUTH OR MYTH?

Cold weather can worsen joint pain Dear HIW,

MOON MOTIVES

Artemis astronauts will further explore the lunar surface

CAREERS IN SCIENCE

Not all lab jobs require a degree Dear

WE ASKED YOU

© LOTM: Julia Higgins / Getty / NASA

THE STORY OF EARTH

Our little blue planet in the Milky Way is truly one of a kind

THE BIRTH OF OUR PLANET

How a cosmic cloud gave rise to life

EARTH’S EVOLVING CLIMATE

From hot to cold and back again “As Earth

THE MAKING OF THE CONTINENTS

Plate tectonics shift the ground beneath our feet, changing the face of the Earth

THE ORIGIN OF LIFE

One common ancestor gave rise to all things

PRIMORDIAL SOUP THEORY

Could life really have started in a warm little pond?

THE EVOLUTION OF LIFE ON EARTH

3.8 BILLION YEARS AGO The very first microbes

THE HISTORY OF EARTH

PAVING THE WAY

PIONEER 10 & 11 Broadly similar to Voyager,

TO PLUTO AND BE YOND

“It would leave the Solar System faster than any spacecraft to date”

HOW TO SURVIVE

ALMOST ANYWHERE

ATTITUDE AS A SURVIVAL TOOL

Panic is never helpful, and in the wilderness

FINDING LIFE-GIVING LIQUID

You need to drink several litres of water every day. Here’s how to find it

HOW TO FIND WATER

There are many ways to find water in the wilderness. Here are four top tips

WARNING!

BEWARE OF BAD WATER

FINDING A PLACE TO REST

A good place to relax is essential, but don’t think you can sleep on open ground

FINDING NATURAL SHELTERS

Using landscape features can help you find shelter more easily

BUILDING AN IGLOO

1 CUT BUILDING BLOCKS Cut blocks from hard,

TOP TIP!

AVOIDING TOILE T TROUBLE

BRIGHTEN YOUR CHANCES WITH FIRE

A fire can keep you warm and dry, but also provides many more benefits

MAKE FIRE WITHOUT MATCHES

There are many ways to make fire without matches, but they take practice

WARNING!

BE CAREFUL WITH FIRE

FIREMAKING’S THREE SIDES

Making fire requires three ingredients, sometimes shown in

FINDING YOUR WAY

If your tools get lost, nature can keep you on track

STARS LIGHT THE WAY

Find the well-known Big Dipper asterism in Ursa

TOP TIP!

STEERING BY THE SUN

KEEPING YOURSELF FED

Nutritious food can often be found alongside the bad

EATS AND DON’ T EATS

What plants to look for and what to avoid in five different environments

HOW FIRESTORMS FORM

What do you get when you cross a fire with a tornado?

DEEP SPACE PROBES

Five of NASA’s long-range spacecraft are heading beyond the Solar System. What will they find?

THE GRAND TOUR

“Five probes have ended up on interstellar trajectories so far”

VOYAGER’S GOLDEN RECORD

Knowing that the Voyagers would eventually venture out

PLANNING THE NEXT MISSION

How about a dedicated interstellar probe? We speak with scientist Kirby Runyon about a far-flung mission

MAJOR TIM PEAKE

The European Space Agency astronaut speaks to How It Works about his time on the International Space Station, life in the universe and careers in space

MEET YOUR TEETH

How these pearlescent facial features develop and are maintained in a healthy mouth

INCREDIBLE ICE

We know that it’s solid water, but that’s just the tip of the iceberg

CARBON: THE MULTI-TOOL OF ELEMENTS

From thick and grimy oil to gleaming diamonds, carbon can take on many roles

WHAT HAPPENS TO RADIOACTIVE WASTE?

Nuclear power is an amazing technology, but cleaning up after it isn’t simple

HOW RISKY IS NUCLEAR WASTE?

Professor Katherine Morris from the University of Manchester, UK, is a top nuclear waste expert

INSIDE THE SAMSUNG GALAXY Z FLIP

Is the flip phone becoming trendy once again?

MILITARY MACHINES

The British Army is using hybrid power to turbocharge its toughest trucks

INSIDE THE JACKAL

Loads of hybrid hardware is crammed into the Jackal. Here are the key elements of this nimble vehicle

THE HYBRID HEAD HONCHO

Lieutenant Colonel Sutthery is a driving force behind the army’s hybrid trucks

HYBRID HOUND

Plenty of components were removed to convert the Foxhound to hybrid technology. Here’s what’s changed

WHO WAS NAPOLEON BONAPARTE?

How the first emperor of France came to power – and his dramatic downfall

NAPOLEON’S GREATEST VICTORY

How Napoleon achieved his biggest military triumph at the Battle of Austerlitz

DUST BOWL DISASTER

Why were the southern US plains host to such huge and intense dust storms in the 1930s?

DUS T AND DOOM

1929 An economic crash caused the Great Depression,

HOW TO READ FAMILY TREES

Just like any great detective, tracing your family’s historic roots takes clever investigative skills