All posts by David L. Kaufman

Saturn: Weirdo of the Solar System

This is an artists concept of Cassini during the Saturn Orbit Insertion (SOI) maneuver, just after the main engine has begun firing. The spacecraft is moving out of the plane of the page and to the right (firing to reduce its spacecraft velocity with respect to Saturn) and has just crossed the ring plane. Cassini's close proximity to the planet after the maneuver offers a unique opportunity to observe Saturn and its rings at extremely high resolution. Image Credit: NASA/JPL
This is an artists concept of Cassini during the Saturn Orbit Insertion (SOI) maneuver, just after the main engine has begun firing. The spacecraft is moving out of the plane of the page and to the right (firing to reduce its spacecraft velocity with respect to Saturn) and has just crossed the ring plane. Cassini’s close proximity to the planet after the maneuver offers a unique opportunity to observe Saturn and its rings at extremely high resolution.
Image Credit: NASA/JPL
There is a giant robot circling planet Saturn right now. And this robot is finding weird, amazing things: rainstorms of liquid diamonds, hurricanes bigger than the Earth, ice volcanoes…

But before we get to all that, I should back up a bit and give just a little background on Saturn so you will fully appreciate these new discoveries. Saturn is the sixth planet from the Sun, the farthest planet that can be easily seen without a telescope.

We have always known that Saturn was unusual. Actually, all of the planets were a little unusual to ancient star-gazers. They studied the night sky and saw that almost all the bright dots in the sky moved at the same speed and direction. But they also noticed that five bright dots in the sky moved differently than the stars and constellations. They called these five dots planets (which means wanderer): Mercury, Venus, Mars, Jupiter and Saturn wander among the constellations of the night sky.

Galileo's Drawings of SaturnMore than 500 years ago, in the year 1610, Mr. Galileo found that Saturn was really weird. He was the first person to point a telescope at Saturn and he saw the most incredible sight; Saturn had ears! His drawings looked a bit like Mickey Mouse, with a big circle in the middle and ears poking out on the right and left side.

Another astronomer, Chris Huygens, using a better telescope, found that the “ear” Galileo saw were actually a ring around the planet, just like one you might wear on your finger. Then a guy named Gio Cassini used an even better telescope and could see that the ring was actually multiple rings (at least three) with clear separations between them.

As Saturn advances in its orbit toward equinox and the sun gradually moves northward on the planet, the motion of Saturn's ring shadows and the changing colors of its atmosphere continue to transform the face of Saturn as seen by Cassini. Image Credit: PIA11141 NASA/JPL/Space Science Institute
As Saturn advances in its orbit toward equinox and the sun gradually moves northward on the planet, the motion of Saturn’s ring shadows and the changing colors of its atmosphere continue to transform the face of Saturn as seen by Cassini. Image Credit: PIA11141 NASA/JPL/Space Science Institute
Over the years, we have continued to learn just how weird Saturn is. Saturn has at least 62 moons and dozens of rings. It is the second largest planet, called a “gas giant” which means that it has no rocky surface, it’s all air. Even though it’s huge (760 times bigger than Earth), the gas is really light. If you could put Saturn in a big enough bucket of water, it would float!

Although it is so big, it spins really fast; a day on Saturn is only about 10 hours long. Gas spinning that fast causes tremendously violent storms. Hurricanes larger than whole the Earth rage across Saturn all the time.

Titan's atmosphere makes Saturn's largest moon look like a fuzzy orange ball in this natural color view from the Cassini spacecraft. Titan's north polar hood is visible at the top of the image, and a faint blue haze also can be detected above the south pole at the bottom of this view. (Image Credit: PIA14602 NASA/JPL-Caltech/Space Science Institute)
Titan’s atmosphere makes Saturn’s largest moon look like a fuzzy orange ball in this natural color view from the Cassini spacecraft. Titan’s north polar hood is visible at the top of the image, and a faint blue haze also can be detected above the south pole at the bottom of this view. (Image Credit: PIA14602 NASA/JPL-Caltech/Space Science Institute)
Saturn’s super moon, Titan, is bigger than planet Mercury and has clouds, lakes, rivers and oceans.

By 1990 we had learned a whole lot about Saturn using Earth based instruments (and two very brief flyby missions). But there is just so much you can do from about 1 billion miles away. To learn more, we needed to get up close and personal for an extended time.

In 1997 we launched robot spaceship to do just that. It was named in honor of Mr. Cassini, and carried a smaller robot onboard named after Huygens. Cassini/Huygens was the biggest spaceship NASA had ever built, over 6 tons, big as a school bus. After a six year journey Cassini/Huygens arrived at Saturn and started sending back jaw-dropping details about our sixth planet.

In the next post, I will share some of the secrets of Saturn uncovered by Cassini/Huygens. Be prepared to be amazed!

Fun Phineas Facts
Saturn’s rings disappear every few years! It happened in 1612, completely shocking Galileo. Then to his surprise, the next year they reappeared.

To understand why, you can do a simple experiment. Find a round disc in your home (a quarter, CD, frisbee…) and hold it out at arms length so it looks like a circle. Now tilt it so all you can see is the edge.

Saturns rings are like the disc in your hand. Saturns rings are very wide, but only 30 feet thick. As seen from Earth, Saturns rings wobble, and about every 7 years they are edge on, and basically invisible to us. Then they wobble some more and reappear.

References:

http://www.space.com/48-saturn-the-solar-systems-major-ring-bearer.html

http://saturn.jpl.nasa.gov/

Museo Galileo

6. How to Think Like a Scientist – The Custard Effect

How to think like a scientist for kidsCustard makes me puke. Violently. Specifically, chocolate custard. It’s my working hypothesis. I only have two data points, but that’s enough for me. Talking like a scientist, chocolate custard causes me to puke. The effect of me eating chocolate custard is: me puking. The arrow of cause ==> effect is one way. My need to puke did not cause me to eat chocolate custard.

Cause and effect. Every scientist studies causes and effects. The cause happens first, and then later there is an effect. Always. It’s so obvious that at times we forget. Cutting onions make me cry. Onions cause me to cry. The effect of cutting up onions is crying. And crying does not cause me to cut onions.

But, when I cut onions, I also always listen to the radio. These two things happen in pairs, but are completely unrelated.

This leads to one of the most important parts about thinking like a scientist: just because things happen together, does not mean that one necessarily caused the other, or that they are even related. Talking like a scientist, if things happen together it is called “correlation”. The biggest mistake people make is when they assume correlation also means causation. There is a correlation between the onions and listening to the radio, but there is no causation.

My favorite football team wins when I wear my lucky T-shirt. Did me wearing my “lucky T-shirt” cause (or even help) my team to win? Probably not. It’s more likely that I often wear that shirt on game days, and my team wins a lot. Correlation does not mean causation,

But sometimes it’s hard to know what’s going on. Thinking like a scientist, I observe:

Every night my dog barks at midnight.

How does my dog know its midnight? She even adjusts for daylight savings time! Is it magic? Does the clock cause my dog to bark?

No! After further investigation, it turns out that she barks every night at midnight because that’s when my neighbor lets his dog outside. Midnight and my dog barking have a correlation. But the cause of the barking is my neighbor’s dog. The time of night had nothing to do with it.

But sometimes it’s hard to know what causes what.

Suppose you find that all the kids who wear glasses also sit in the front row of your class. Does sitting up close cause their eye problems? Or are they sitting up close because they have eye problems?

The great thing about noticing correlations is that it leads to ideas for new hypotheses and experiments. The experiments will provide evidence either supporting causation or falsify the idea.

For instance, I could ask my neighbor to let his dog out at 10pm to see if my dog will bark early. Or I could do custard flavor experiments. Maybe I only puke on chocolate custard and I will love strawberry custard…


Fun Phineas Effect Facts
One of the most common grammar mistakes in the English language is confusing the words ‘effect’ and ‘affect’. Wow your English teachers by never mixing them up.

Effect with an E is a noun, meaning ” the result of”. What was the effect of me eating chocolate custard? Puke.

Affect with an A is a verb meaning “to influence or change”. Verbs are action words. Remember: A for action. Bad weather affects my mood. So does puking.

Falling Felix

fallingfelix

Imagine a roller coaster plunge that lasts over four minutes…

So there was this guy, Felix, who fell from outer space to the earth, without a spaceship. For real! He fell faster than a .22 caliber bullet fired from a rifle. He fell faster than his own screaming voice, faster than the speed of sound itself. And he lived to tell about it. You can watch him do it.

Have you ever ridden a roller coaster? You know the feeling you get in the pit of your stomach when you take that first plunge? Scientists call it “free fall”. On a ‘coaster, this feeling lasts a few seconds. People who jump out of airplanes with a parachute (skydivers) experience free fall for about 60 seconds. Felix experienced free fall for over four minutes when he fell from outer space.

In 1947, Air Force pilot Chuck Yeager was the first human to “break the sound barrier” traveling faster than the speed of sound (also called Mach 1). He did this in a special fighter jet airplane. At the time, scientists weren’t even sure if humans could go that fast and live. Nowadays, supersonic (faster than the speed of sound) jet airplanes are commonplace, but back then it was almost science fiction. But, as impressive as that is, imagine going that fast without the jet airplane!

Sixty-five years later to the day, in October 2012, daredevil skydiver Felix Baumgartner jumped out of helium balloon from 24 miles up (over 127,000 feet). This is 4 times higher than most jets fly. There is only 2% of the Earth’s atmosphere at that height, 98% of the air is below.

The mission was named Red Bull Stratos. Felix wore a suit similar to NASA astronaut suit because at that height there is no air to breathe and it is wicked cold. Felix fell for over ten minutes and landed safely with a smooth parachute landing. He reached a maximum supersonic speed of 833 miles per hour (Mach 1.24).

Felix set the world record for the highest skydive ever, and the fastest free fall ever. His accomplishment didn’t just make the record books, it provided scientists with incredible information that will help them build safer space suits and train future astronauts (maybe even you).

Watch the incredible video shot from his helmet-cam and by his Red Bull Stratos crew.


Fun Phineas Falling Felix Fact
One record Felix did not break was the longest free fall ever. Felix fell for 4 minutes, 16 seconds, falling short (pun intended) of the record set by Joe Kittinger of 4 minutes 36 seconds. Even though Felix jumped from a much higher altitude, he was going so fast, Joe fell 20 seconds longer!


References

Web site: Felix Baumgartner – Red Bull Stratos

Web Site: Free Fall on Wikipedia

Photo Credit: Red Bull Stratos in Roswell, New Mexico, USA on October 14, 2012. (Red Bull Stratos / Red Bull Content Pool)

5. How to Think Like a Scientist – Controlling the Chocolate Chip Experiment

phineas_scientist001So I learned how to make my mother’s delicious chocolate chip cookies. But after a few batches I got bored, and like a scientist, started to experiment. My mom didn’t enjoy walnuts and rarely baked with them, but I love them. I decided to change her recipe and add walnuts to my mix. Success! My roommates and I thought they tasted great (except for my friend Tony, who is allergic to nuts).

But were the cookies better than the original recipe? It was hard to know. It was hard to remember exactly how the originals tasted. So, thinking like a scientist, the next time I divided the cookie dough into two bowls and added walnuts only to one of them. I baked both batches and we did a taste test. The walnut chocolate chip cookies were clearly superior. And Tony was happy.

Talking like a scientist, the batch of original recipe cookies was the control group and the walnut batch was test group. The original ingredients are called dependent variables and the walnuts the independent variable.

The mark of a good experiment is that it is a controlled experiment with only one independent variable. You only want to change one thing at a time so you know what you are testing. The control allows you to compare the results of the change.

It is fine to do an uncontrolled experiment (like I did with my first attempt at walnut cookies). But if the results are good, it should be followed by a controlled experiment to verify them.

Scientists use uncontrolled experiments to generate ideas for new hypotheses. Hey, what if I throw in some jalapeño peppers into the cookie dough?

Fun Phineas Fact
In medical research, controlled experiments are called clinical trials. Over the years, it has been shown that the results are more accurate if the patients don’t know whether they are in the control group or the test group. We call these blinded trials.

Think about doing a soda pop taste test with your friends. Then try it again putting a blindfold on them before they drink. Blinding prevents personal opinions from altering results.

It has been found that results are even more accurate when the doctors and nurses running the experiment don’t know which group is the control. We call these double blinded trials. A double blinded controlled trial is difficult and expensive to run, but is the gold standard of medical research.

The US Food & Drug Administration requires double blinded clinical trials be run before approving new medications.