Digital Art and Space Blog
Reflections on Art, Computer Graphics, Photography, Space and Astronomy

Are the Stars Out Tonight?

I just got an e-mail in my JPL Solar System Ambassador Inbox about a new survey that is underway for amateur astronomers. Note that the survey must be done by Monday October 8. What is the survey about? To quote from the e-mail:

“Through funding from the National Science Foundation, the Astronomical Society of the Pacific (ASP) and the Institute for Learning Innovation (ILI) are conducting a national study to better understand the amateur astronomy community and the activities and mechanisms that promote astronomy education to the public… By completing this survey, you are eligible to enter into a drawing for one of five $50 gift certificates to Sky and Telescope’s online store.”

The survey is a part of a program titled “Sharing the Universe”. I just completed the survey myself. It is straight forward and there were no questions that anyone could consider an invasion of privacy. If before taking the survey you would like to know more, then visit the Astronomical Society of the Pacific’s Sharing the Universe page.

Again, the deadline is Monday October 8. The survey only takes a few minutes so why not take the survey right now. Take me to the Survey.

About the Picture

The picture used to illustrate this post, titled Are the Stars Out Tonight? is a small section of a starfield that I am working on in Photoshop. The starfield will serve as a background for an as yet to be determined foreground scene.

Ad Astra, Jim

Spiral Galaxy M101 by Jim Plaxco

Some of you may recall the Mars crater identification project that asked for volunteers to identify martian craters. Named Clickworkers, the project has since been expanded to include review of Mars Reconnaissance Orbiter HiRISE camera images. More about that in an upcoming post.

Now a similar project has been created for the purpose of classifying galaxies. Galaxy Zoo, which opened July 10, is an online project that uses volunteers to visually inspect small deep space pictures in order to identify the type of galaxy seen in the image.

Your job as a classifier of galaxies is to determine whether the image is of a spiral galaxy, elliptical galaxy, merging galaxies, or not a galaxy at all. If it is a spiral galaxy, then one needs to identify whether its rotation is clockwise or anti-clockwise. Figure 1 below shows a sample screen shot, reduced in size for display here.

Figure 1. Galaxy Zoo screen shot shown reduced in size.

Unlike Clickworkers, Galaxy Zoo volunteers need to register and pass a test. The test consists of correctly identifying at least 8 of 15 galaxy images. When I took the test I got 13 out of 15 correct. I’m fairly sure of the ones I got wrong. These were objects that were quite fuzzy and I basically just gave it my best shot. Unfortunately there is no feedback given to tell you which ones you did get wrong. That feedback would definitely be useful.

Once you’ve passed the test, you are then free to begin analyzing galaxy pictures. One word of caution: the galaxies that are used in the tutorial section to give you practice at identifying galaxies are, in my opinion, representative of rather clear cut cases. Many of the galaxy images that you are asked to classify are little more than pixellated smudges so be prepared for a challenge.

While classifying, one cool tool at your disposal is the SDSS Skyserver Object Explorer. You access this tool by clicking on the Galaxy Ref. link (see orange text, upper right in Figure 1). There you will find quantitative information about the image you are analyzing. From this tool you can click on the image shown which takes you to a new window for the SDSS DR6 Finding Chart Tool. This tool allows you to zoom in and out on the image you are analyzing. You may find this useful for those hard to classify galaxies.

There are a Sagan’s^#1 worth of galaxies awaiting classification so what are you waiting for, get over to Galaxy Zoo because the more of us that help, the quicker the job will be done. Incidentally, M101 (the galaxy shown at the top of this post) is a counter-clockwise rotating spiral galaxy.
Note 1. One Sagan = Billions and billions.

Ad Astra, Jim

Image: Fate of the Sister by Jim Plaxco. A depiction of a binary star system in which one of the stars has gone supernova. Original image size: 27 x 21 inches.

I recently discovered a great collection of free online courses being offered by MIT (Massachusetts Institute of Technology). Known as MIT OpenCourseWare, it consists of complete courses in a wide variety of disciplines. You don’t even have to register - just download the files to your computer. The courses provide lecture notes, review problems, quizzes, and solutions using a combination of html, xml, and pdf files.

What caught my eye were the Aeronautics and Astronautics and the Physics sections. Classes in the Physics section that I downloaded are:

• Relativity
• Introduction to Special Relativity
• Exploring Black Holes: General Relativity & Astrophysics
• Introduction to Astronomy
• Modern Astrophysics
• The Early Universe
• Cosmology
• Astrophysics I

Closer to home the section Earth, Atmospheric, and Planetary Sciences contains a number of interesting courses including:

• The Solar System
• Hands-On Astronomy: Observing Stars and Planets

Lastly, for the budding rocket scientist there is in the Aeronautics and Astronautics section the following courses:

• Rocket Propulsion
• Space Propulsion

In fact there is easily more than enough material available to keep the enquiring mind busy for years. My advice: go forth and learn.

Ad Astra, Jim

While surfing the web, I came across a great resource for lunar observers and anyone else interested in our Moon. The book is “Photographic Moon Book” and was written and illustrated by Alan Chu. The book is a 225 page 100 megabyte PDF. Most amazing about this high quality reference book is that it is free. This particular edition of the book was just released this month so my coming across it just now was a happy coincidence.

The book is divided into several sections. About This Book provides the reader with a brief introduction to the book itself.

An Overview provides a general introduction to the Moon and to observing the Moon.

The Lunar Features & Events section consists of 33 MAP subsections that in addition to abundant observation details also contains selenographic information. Following the maps are four EVENT subsections that each discuss in detail libration, the lunar terminator, the crescent Moon, and eclipses and occultation.

The book then jumps to the Farside of the Moon making use of Apollo images, then pausing to cover lunar features named after Chinese persons.

Lunar Spacecraft provides a very brief overview of the unmanned and manned missions to the Moon. A map of the location of lander missions to the Moon, both manned and unmanned, is also provided.

The Methods of Imaging section is an introduction to photographing the Moon.The author provides information on a couple different techniques as well as camera related settings.

The book’s appendices consist of the following sections:

• Data of Lunar Images provides photographic and observational information about the author’s lunar photos used in the book,
• Data of the Moon provides a numerical summary of the Moon’s characteristics,
• Glossary contains a number of useful definitions,
• References provides a list of books and web sites for more information,
• Crater List provides the name, longitude, latitude, and diameter for named craters,
• Index that looks to be quite thorough.

Coming across this excellent lunar reference was really a treat and I give it two thumbs up. Thank you Alan Chu for creating this excellent reference guide to the Moon and making it available to the public for free.

Download Site for Photographic Moon Book

Ad Astra, Jim