Category Archives: Astronomy

Two Enduring Star Books for Curious Readers by H.A. Rey

rey_ha_astronomy

Find the Constellations & The Stars: A New Way to See Them by H.A. Rey

It’s not surprising that two astronomy books written by H.A. Rey more than 50 years are still popular. After all, Rey is the same writer/illustrator who, along with his wife, Margret, invented Curious George. The adventures of that famous cartoon monkey have entertained kids by the millions.

H.A. Rey thought the old way of showing constellations made them hard to remember. He thought drawing lines between the stars worked better. He was certainly right when it comes the The Twins.
H.A. Rey thought the old way of showing constellations made them hard to remember. He thought drawing lines between the stars worked better. He was certainly right when it comes the The Twins.
In both his astronomy books, Rey used a new way to draw constellations (or star groups) that he believed made them easier to find in the sky. Instead of placing fancy pictures over the stars to help readers visualize the constellations, he connected the stars like giant dot-to-dots. It works much better in some cases, but not all.

Another thing Rey did in both books is use English names for constellations — for instance, saying “The Bull” rather than “Taurus.” This also works OK, but can be confusing if everyone else is using the old names. As a fan of language, I think part of the fun of new hobbies is learning new words.

Both books are about looking at the sky and learning to find your way around the constellations. Rey writes that the books are meant for people “who want to know just enough about the stars to find the major constellations.” As every backyard astronomer knows, that’s the right place to start.

H.A. Rey had fun making the drawings for Find the Constellations, which he wrote for younger beginners.
H.A. Rey had fun making the drawings for Find the Constellations, which he wrote for younger beginners.
Of the two books, Find the Constellations is intended for younger readers. At only 72 pages, it is thin and features funny cartoons that kids will enjoy. Don’t let the laughs fool you. There is a lot of good information in Find the Constellations and it includes my favorite feature introduced by Rey: star-finding practice exercises!

Looking at star maps with lines or images placed over the constellations is one thing, but it is easy to be bewildered by the actual sky when you look up and see hundred of points of light. So Rey lets you practice by placing identical maps of the sky side-by-side on the page. One version has lines and stars; the other only stars. You can start training your mind to recognize star patterns and to associate them with constellations. And you can do it from the comfort of your favorite chair!

Sometimes trying to make sense of the night sky can be hard. So H.A. Rey lets readers practice comparing the star shapes they have memorized to the points of light they'll see outside.
Sometimes trying to make sense of the night sky can be hard. So H.A. Rey lets readers practice comparing the star shapes they have memorized to the points of light they’ll see outside.
The Stars: A New Way to See Them is also listed as a beginners guide to the stars, but contains more in-depth information about the star and constellations. It has more history and detailed star maps. While the presentation of the material is intended for older beginners, there are still cartoons and humor throughout the book.

What The Stars has that is completely beyond the scope of Find the Constellations, however, is a Part 4 section titled “Some Hows and Whys.”

In Part Four of The Stars,  H.A. Rey walks fearless readers through the geometry behind the nightly show stargazers see in the skies.
In Part Four of The Stars, H.A. Rey walks fearless readers through the geometry behind the nightly show stargazers see in the skies.
This section provides an orderly explanation of how factors such as the tilt of the earth’s axis and the earth’s constant progression around the sun lead to an ever-changing sky. It touches on geometry and demonstrates — again in a straightforward, relaxed style — how everything from navigating the seas to the changing seasons relates to the same factors.

Some people worry that presenting information that is beyond students can be discouraging to them, but I don’t think that is an issue here. In fact, Rey includes a cartoon at the beginning of the section warning that the road is going to be getting a little rougher ahead and that readers “should proceed at their own risk.”

So even if some of the concepts are advanced, daring students will be exposed to the notion that events such as eclipses, seasonal changes, solstices aren’t things that just happen. They happen predictably, for a reason. And they can be understood.

And when you know that, you are already one step closer to grasping the big picture, a big picture that took humankind thousands of years to figure out.

You begin to see yourself standing on the surface of a huge body that is in motion through three dimensional space. You begin to see something amazing about yourself, simply by looking up.

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

‘Stars’: Still Shining After All These Years

This first astronomy book I ever bought is still hanging in there more than 40 years later. Inside the back cover, I updated the positions of Jupiter and Saturn for 1974-75 after the charts inside the book became outdated.
This first astronomy book I ever bought is still hanging in there more than 40 years later. Inside the back cover, I updated the positions of Jupiter and Saturn for 1974-75 after the charts inside the book became outdated.
When I was 7 or 8 years old, my parents took me to a planetarium. Planetariums are theaters that use large projectors to display stars and planets overhead on a darkened dome. The lights went down, I settled into my plush seat, and the show began.

I was amazed as diamond-like star projections of constellations moved across the dome, recreating the sky from sunset to sunrise in just 30 minutes. The lecturer pointed out star patterns (Ursa Major, Cygnus, Draco…) and projected over them images of the animals (a bear, a swan, a dragon…) they represented. It made them easy to remember. By the time the show ended, I was hooked.

In the gift shop outside the planetarium, I bought my first astronomy book — a Golden Nature Guide titled “Stars.” More than 40 years later, I still have it.

That book and $20 telescope from the local department store made up my entire astronomy kit until I got to college and had access to better telescopes. That was when I learned that trying to use a toy telescope on a shaky table underneath a street light had been an iffy plan. But the book was great. It still is.

“Stars: A Guide to the Constellations, Sun, Moon, Planets and Other Features of the Heavens” was originally published in 1951. Written by Herbert S. Zim and Robert H. Baker, it features 150 illustrations by James Gordon Irving. The book has exactly the information promised in its subtitle and provides plenty of text and information, more than enough to satisfy any budding astronomer who wants to curl up with a interesting book.

Think of this book as an overview to the topic of astronomy. Sure it has star maps, but there are better books for finding your way around the sky. But don’t hold that against it. The maps are small because this handy book is sized to fit into your pocket.

My copy cost me $1.50, which turned out to be a real bargain given how long I have used it. On the downside, the charts printed in it only go through 1970. But I was able to find the information and update some of the charts by hand for 1974-1976.

The highly successful Golden Guide series of books was out of business for awhile, but has come back, so this book is still available. It has been updated, but some reviewers still say it is no longer as accurate as it should be. Perhaps in a future post we’ll get a copy and see what has changed. But I know the stars haven’t changed (and we’ve only lost one planet!) so it is hard for me to imagine this not still being a handy introduction to the night skies.

You’ll add other great books to your astronomy bookshelf over time, but “Stars” is a great place to get started.

Armchair Explorer: Postcards from the Red Planet

mars_rover
Self-Portrait of Mars Rover Curiosity – NASA/JPL-Caltech/MSSS


No matter how far you go, it’s always nice to keep in touch with the folks back home. That’s especially true for a spacecraft that has traveled millions of miles just to send pictures and other information from the surface of Mars back to scientists on Earth.

On June 19, researchers at NASA released their biggest, most detailed picture ever of the surface of Mars. For space fans following the progress of NASA’s Mars rover — named “Curiosity” — as it explores the surface of the Red Planet, pictures are nothing new. One of the great things about NASA is that mission scientists share lots of the data sent back to Earth. Armchair explorers can browse information on the Web — photos, charts, maps, animations and multimedia — alongside scientists around the world.

But the latest picture is NASA’s hugest ever (in camera terms, more than one billion pixels!), which means you can change your viewing angle, move it around and look at different parts of it. When you see something interesting, you can zoom in for closer inspection. See an interesting rock a mile away? No problem. Click and zoom until you get a better look.

It’s as close as you can get to taking a stroll around the surface of Mars.

Billion-Pixel View of Mars Surface with Pan and Zoom

The reason such detail is possible is that the image is made by stitching together nearly 900 pictures taken by Curiosity as it moved around the surface. The pictures were taken over several days in the October and November of 2012. The area photographed includes a windblown patch named “Rocknest,” and extends to Mount Sharp on the horizon. “It gives a sense of place and really shows off the cameras’ capabilities,” said Bob Deen of the Multi-Mission Image Processing Laboratory at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.

To access the image and start your own “roving” adventure, go click on the link above.


TERMS

NASA: National Aeronautics and Space Administration, an independent agency of the United States government responsible for aviation and spaceflight.

PIXEL: The basic unit of the composition of an image on a display screen; basically, one single dot that can’t be divided.


SOURCES

PRESS RELEASE: Billion-Pixel View of Mars Comes From Curiosity Rover

WEB: NASA’s Mars Science Laboratory

WEB: NASA’s All About Mars

WIKI: Mars Science Laboratory

WEB: Information on NASA’s Multi-Mission Image Processing Laboratory


PHOTO CREDIT

Image credit: NASA/JPL-Caltech/MSSS “Updated Curiosity Self-Portrait at ‘John Klein'” This self-portrait of NASA’s Mars rover Curiosity combines dozens of exposures taken by the rover’s Mars Hand Lens Imager (MAHLI) during the 177th Martian day, or sol, of Curiosity’s work on Mars (Feb. 3, 2013), plus three exposures taken during Sol 270 (May 10, 2013) to update the appearance of part of the ground beside the rover. The updated area, which is in the lower left quadrant of the image, shows gray-powder and two holes where Curiosity used its drill on the rock target “John Klein.” The portion has been spliced into a self-portrait that was prepared and released in February (http://photojournal.jpl.nasa.gov/catalog/PIA16764), before the use of the drill. The result shows what the site where the self-portrait was taken looked like by the time the rover was ready to drive away from that site in May 2013.

The rover’s robotic arm is not visible in the mosaic. MAHLI, which took the component images for this mosaic, is mounted on a turret at the end of the arm. Wrist motions and turret rotations on the arm allowed MAHLI to acquire the mosaic’s component images. The arm was positioned out of the shot in the images, or portions of images, used in the mosaic.

Malin Space Science Systems, San Diego, developed, built and operates MAHLI. NASA’s Jet Propulsion Laboratory, Pasadena, Calif., manages the Mars Science Laboratory Project and the mission’s Curiosity rover for NASA’s Science Mission Directorate in Washington. The rover was designed and assembled at JPL, a division of the California Institute of Technology in Pasadena.

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.


SOURCES

WEB: Space.com: Dwarf Planets

WEB: NinePlanets.org

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.