Dear Penny,
Blue oceans, green forests, a cozy blanket of oxygen. Our planet is a super comfy home. It’s hard to imagine there was ever a time it didn’t exist.
I asked my friend Julie Ménard how Earth formed. She’s a planetary scientist at Washington State University.
She told me it started with the Big Bang. That was nearly 14 billion years ago.
“The Big Bang is not an explosion,” Ménard said. “It’s an expansion. Everything in our universe today was in a tiny spot—smaller than the eye can see. Eventually, the pressure and density got so high that it started to expand.”
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Read More ...Dear Lucy,
When I go to the veterinarian, they measure how big I am. They use a scale to check my weight. They find my length and height with a measuring tape.
But nobody can put a planet on a scale. Or wrap a measuring tape around it.
I asked my friend Katie Cooper about it. She’s a geologist at Washington State University. She studies our planet and other planets, too.
She told me we send satellites to orbit our solar system. When a satellite swoops around a planet, it snaps pics and takes measurements. Those images and measurements help scientists estimate the … » More …
Read More ...Dear Ia,
I looked through a high-power telescope for the first time in college. I couldn’t believe how many stars I saw. It’s hard to imagine all the planets orbiting all those stars.
I talked about how we know those planets are out there with my friend Jose Vazquez. He’s an astronomer at Washington State University.
He told me that scientists look for planets outside our solar system using a number of instruments—like a photometer. That's a tool that attaches to a telescope and measures light.
Read More ...Dear Heidi,
It’s a big week for Pluto as NASA’s New Horizons spacecraft gets a close-up look at the distant, icy world. But first, the answer to your question: Pluto is not a planet.
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