Science for Kids — August 30: Telescopes, walking fish, and a chicken-sized dinosaur

Professor Pip adjusted his slightly crooked spectacles and patted his forest-green lab coat until something clinked. "Ah, precisely!" he said, pulling out a small brass telescope and a rolled-up star chart.

The hilltop was dark. The first stars were beginning to prickle through the deep blue sky above.

"Today, my dear scientists," he announced, tail swishing, "humans launched a brand-new eye into space. And I want us to think about why anyone would want an eye that big, all the way out there."

"Bigger than yours?" giggled Mia.

"Oh yes, much!" Pip laughed. "Let's start small, though. Leo — squint at that porch light way down in the valley. Now, look through my telescope."

Leo squinted. Then he lifted the little brass telescope to his eye. "Whoa! I can see the moths flying around it!"

"Excellent!" Pip beamed. "A telescope is a light bucket. A bigger bucket scoops up more light — so you can see faint, faraway things that your plain eyes miss."

He unrolled the star chart, and it fluttered like a paper flag. "Now here is our puzzle. Space is enormous. If you point a normal telescope at the sky, you only see a tiny keyhole of it. This new one — its name is Roman — has a keyhole one hundred times wider than another famous telescope called Hubble. Imagine trying to find one lost penny in a park. Would you rather look through a straw…"

He curled his paw into a tube and squinted through it.

"…or through a big picture window?"

"The window!" cried Mia. "Duh! You'd see the whole grass!"

"Precisely!" Pip clapped. "Roman is a picture window. It will scan enormous patches of sky at once, snapping pictures so big that not even a giant TV could show all the pixels."

Leo scrunched his nose. "But what's it looking for?"

"Ah! Two things, mostly." Pip counted on his paw. "One: exoplanets — planets around other stars. Roman will use a special trick to block a star's bright glare, so we can spot the tiny, faint planets circling it. Two: dark matter and dark energy — invisible stuff that makes up most of the universe. We don't know what it is. Roman will help us find out!"

The children stared up at the sky. A single satellite blinked slowly across the stars.

"That could be Roman," Pip whispered. "Off on a three-month journey to its parking spot. Somewhere out there, it will send back pictures of worlds no one has ever seen before."

He tucked the star chart back into his pocket. "Now I wonder — if you could aim it at anything, what would you want it to see first?"

Professor Pip's pockets were dripping. He had just come up from the riverbank carrying a great glass bowl of water — and inside the bowl, something orange scuttled sideways across the pebbles.

"Oh my whiskers!" he cried, plopping the bowl onto the dock. "Come see, come see!"

Mia leaned so close her nose fogged the glass. "What is that? It looks like a shrimp wearing a fish costume."

"You are very close!" Pip laughed. "Scientists actually nicknamed it a 'fish-prawn hybrid.' It's called an armored sea robin. And today, my friends, we're going to learn how a fish can walk."

Leo frowned. "Fish don't walk. Fish swim."

"That is what everybody thought!" Pip pulled out his magnifying glass and held it up to the bowl. "Look at its fins."

The kids squinted. The sea robin had two big fan-shaped fins on its sides — like little skirts — but poking out below them were six spindly finger-like rods, tapping the pebbles one at a time. TAP. TAP. TAP.

"Those little rods are called fin rays," Pip whispered. "Most fish keep them tucked inside their fins for swimming. But sea robins have set them free — like tiny legs. Each one moves on its own, just like your fingers."

He wiggled his own paw-fingers to show them.

"But watch this." Pip gave the bowl the gentlest little bump. Startled, the sea robin turned — and skittered sideways along the pebbles, then backwards!

"NO WAY!" shouted Leo, jumping up.

"Way!" said Pip, tail swishing wildly. "Real scientists filmed this last week, four thousand feet down in the sea, with a submarine. It's the first time anyone has seen a fish walk sideways or backwards. Not a single other fish on Earth is known to do it."

"Like a crab!" Mia said. "Crabs go sideways!"

"Exactly right!" Pip clapped. "The sea floor is a bit like a crowded pantry — you have to sneak between rocks and reach into little pockets to find snacks. Walking gives the sea robin control that swimming can't. And those little fin-fingers can even taste the sand as they tap — feeling for hidden worms and tiny shrimp."

He looked down at the fish and softened. "For hundreds of years we thought we knew what fish could do. Then we sent a camera into the deep, and the ocean surprised us again. That's the beautiful thing about science, isn't it? The world is always a little wilder than we imagined."

He handed Mia and Leo a smooth pebble each. "Now — hold this like a fin ray. Can you 'walk' it across the dock with just your fingertips?"

Professor Pip knelt on a patch of rusty-red sandstone and pulled a very tiny fossil brush from a very stuffed pocket. His forest-green lab coat was smudged with desert dust. His spectacles slid almost off his nose.

"Ah!" he whispered. "Careful now. What's under this sand is very, very small."

Mia held her breath. Leo held his magnifying glass so tight his knuckles were white.

Pip swished, swished, swished the brush. Tiny bones appeared. A skinny leg. A slender rib. A little skull no bigger than a plum.

"That…" Mia whispered, "is tiny. That can't be a dinosaur."

"Oh but it is!" Pip's tail poofed with excitement. "This little friend is called Alnashetri. Nickname: Alna. Scientists just dug her up right here in Patagonia. She lived ninety-five million years ago — and she was smaller than a chicken."

To make his point, Pip reached into another pocket and — with a soft bwok! — produced a small chicken, which blinked and started pecking at pebbles. He set it right next to the fossil skeleton.

"See? Same size, roughly."

"But… wasn't Argentina full of GIANT dinosaurs?" Leo said. "Like really giant?"

Pip pointed toward the horizon, where a huge dark shape was moving slowly through the imagined past. "Yes! Argentinosaurus. Giganotosaurus. Some of the biggest animals ever to walk on land — as long as three school buses. Alna lived right beside them."

"How did she not get squished?!" gasped Mia.

"Ah, that's the science!" Pip pushed his spectacles up. "In every ecosystem, different animals do different jobs. The giants ate leaves at the treetops, or hunted other giants. Nobody bothered chasing a tiny snack like Alna — it's not worth the effort. Meanwhile, tiny Alna could hunt fast-moving bugs, lizards, and little mammals that a big dinosaur could never catch. This is called a niche — the special job an animal has in its neighborhood."

He tapped Alna's long leg bones. "Look at these legs. Long. Springy. Perfect for zooming across the sand. And her cousins had feathers — so scientists think she was fluffy, too."

"Oh! Like how a mouse and an elephant can live in the same forest," Leo said slowly, "because they eat different things."

"Precisely!" Pip grinned. "The world of dinosaurs wasn't just big. It was every size. Enormous ones stomping across the plains — and tiny brave ones like Alna darting between their toes."

The desert wind ruffled the chicken's feathers.

Pip closed his notebook softly. "Now I wonder… somewhere in your own backyard, there are big animals and tiny animals doing very different jobs. What do you notice next time you look?"