Category Archives: Mac’s Notebook

What Happened to Planet Pluto?

planet_pluto_facesFor 75 years, kids around the world learned about the nine planets that go around (orbit) the sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. And then in 2006, Pluto was gone; there were only eight planets! What happened to Pluto?

Pluto was discovered in 1930 by Clyde Tombaugh at the Lowell Observatory in Arizona. And from the beginning we knew that Pluto was weird. It was not like the other eight.

It was usually the farthest planet from the sun, though sometimes it was closer than Neptune. It was tiny, smaller than Earth’s Moon. It wasn’t round either, more like a potato than a ball.

And while the other eight planets orbits are almost circular, Pluto’s orbit was a deep oval (like the shape of an egg). And it has 4 moons, one almost as big as Pluto itself.

None of that bothered space scientists (astronomers) until 2005 when they found a 10th planet, Ceres! Ceres is bigger than Pluto, but just as weird. But just when they were about to update all the textbooks to include #10, they found an 11th, Eris.

Soon astronomers realized that Ceres and Eris were just some of hundreds of objects orbiting way out past Neptune. If Ceres is a planet, then they all are! Imagine having to memorize all of them for a science quiz!

So the scientists changed the definition of “planet.” Definitions are really important in science. They keep everyone in the world talking the same language. So making the change was a big deal.

After much debate, they agreed that to be called a planet, you needed to:

  1. Be nearly round like a ball
  2. Have an orbit close to a circle around the Sun
  3. Have cleared out the neighborhood (orbit) of other floating junk

Pluto, Ceres and all the others did not meet the definition and were officially renamed “Dwarf Planets.”

So, Pluto is still out there, but it is no longer considered a planet. However, it’s still a weird, cool rock. And we are about to learn even more about it In 2015, a NASA rocket arrives at Pluto! The “New Horizons” mission will take the first ever close up look at the most famous dwarf planet.

Fun Phineas Fact: Planet Pluto was named by an 11-year-old girl from England.


WEB: Dwarf Planets


WEB: UniverseToday – Interesting Facts About Pluto

PODCAST: Astronomycast Episode #1

PHOTO CREDIT: NASA, ESA, and M. Buie (Southwest Research Institute): This is the most detailed view to date of the entire surface of the dwarf planet Pluto, as constructed from multiple NASA Hubble Space Telescope photographs taken from 2002 to 2003.

Sticky Situation: Million-Year-Old Bugs Preserved in Fossilized Amber

spiderattackIf you’ve ever handled a freshly cut Christmas tree or spent an afternoon climbing a neighborhood pine, you know that trees can get pretty sappy. Part of the healing process for a tree that loses a limb or gets a cut in its bark is to fill in the damaged area with sticky, gooey, sappy resin.

This helps the tree form something like a scab. The scab keeps out bad things (like germs) and keeps in good things (like water).

While this excellent healing process is great for the tree, it can be pretty crummy for insects that come along and get stuck in the sap.

But that is not the end of the story.

Fast forward a few million years, and the scientist of today can find well-preserved insect fossils still in the sappy resin. By this time the resin has turned into a fossil itself, called amber.

Researchers have found all kinds of ancient insects in amber, and have found frogs, flowers, lizards, even the bones of small mammals and animal hair. For scientists studying creatures that are mostly long gone, amber adds up to a real treasure trove.

Recently, scientists at Oregon State University have been studying a rare amber fossil that trapped a spider just as it was attacking a wasp that had just gotten stuck in the spider’s web. The spider was moving in for the kill when resin covered the web, freezing them both for all time. Talk about your sticky situations.


Fossil:  the remains or impression of something that was alive in prehistoric times, now preserved in rock

Resin: a thick substance that flows from some types of pine trees

Amber: fossilized resin

Mammal: warm-blooded animals with hair or fur that fed their young milk


PRESS RELEASE: Fossil of ancient spider attack only one of its type ever discovered

WEB: Fossil Information on

WEB: World of Amber: What is Amber?

WEB: Fossils for Kids

ARTICLE: New York Times: Mammal Bones Found in Amber for First Time

WEB: Resin & Tree Damage


© 2012 Oregon State University: “This is the only fossil ever discovered that shows a spider attacking prey in its web. Preserved in amber, it’s about 100 million years old.”

Swarm Alert! Flying Robots Take On Hurricane Research

flow2_fHave you ever heard of “going with the flow?” That’s the idea behind a new generation of small, computer-controlled, airplanes being built to spy on hurricanes. They are only six inches long and weigh less than a iPod Nano, but scientists at the University of Florida believe they are more than a match for the monster storms.

Instead of trying to fight their way through a storm large enough to be seen from space with winds that can reach 200 miles per hour, these aircraft will be positioned near the path of the hurricane so they get pulled in when the storm gets closer. Once they are grabbed by the winds, they power down and go along for the ride. They gather data the whole time, and are smart enough to make small adjustments to stay in place as the storm moves along. They’ll send information about the storm to the laptop computers of scientists stationed hundreds of miles away.

Today, scientists who want to get up close and personal with a hurricane have to build big, expensive airplanes that are strong enough to fly through the storms dropping sensors that send back information as they fall to Earth.

Because the new flying sensors are small and inexpensive, researchers will launch hundreds of them into a single storm, getting data from lots of places all at the same time. This new technology should be ready to test on a real hurricane within two or three years. So in the future, we should understand the storms better than ever.


PRESS RELEASE: Tiny Airplanes and subs could be next hurricane hunters. University of Florida (2013, June 4).

Hurricane Information from Weather for Kids

NASA Hurricanes and Tropical Cyclones Pages

Hurricane Aircraft — Technological Marvels That Fly Through Storms

Eric Zamora/University of Florida: “GAINESVILLE, Fla. — Autonomous flying drones like this one are the result of research by Kamran Mohseni and graduate researchers with the Institute for Networked Autonomous Systems in the department of mechanical and aerospace engineering at the University of Florida. Photo taken May 30, 2013.”

Scat Dogs of the High Seas


File this post in the “Things you might never know if you don’t go to the museum” category.

Whales are mysterious creatures, but scientists can learn a lot about them by studying whale poop. They can learn about the whales’ eating habits, whether they are male or female, whether they are healthy or under a lot of stress. The scientists can even use DNA testing to identify individual animals and learn whether female whales are pregnant.

That’s useful information. But here’s the problem: finding whale scat (scat is another word for animal poop) in something as large as the ocean is like looking for a needle in a haystack.

Luckily, there’s a solution.

As anyone who has ever walked a dog knows, dogs love to sniff. Sniffing around the ground, for a dog, is like reading a good book with a complicated story. The weirder the smells, the more interesting the story.

So imagine the lucky dog that gets to go out on the trail of some of the Earth’s largest creatures.

Once they are trained to know what to sniff for, dogs riding in the front of boats can help marine biologists find whale poop floating in the water. Dogs can even smell whale poop from one mile away, which you have to admit is pretty amazing.

Since learning how to get help from trained pooches, scientists now find four times as much, err…, research material, as they used to find. That means they have greater access to all kinds of useful data. Not bad.

Another Interesting Thing About Whale Poop: Sometimes poop from a whale with an upset stomach contains a particular substance that hardens into a waxy, almost rock-like object after floating around the surface of the sea for years and years. It is called ambergris and can wash up on any beach in the world. It has a unique smell that is very valuable to perfume makers. In 2012, an 8-year-old boy walking on a beach in England found a chunk of ambergris that weighed a little over a pound. It turned out to be worth $63,000.

Scat: another word for animal poop
Ambergris: waxlike substance that originates in the intestines of a sperm whale

North Carolina Museum of Natural Sciences

Science for Kids

National Geographic