Thursday, June 23, 2016

Astronomy is Exciting: Here’s Where You Can Learn More

Astronomy is a fascinating and vibrant field, with important discoveries occurring at an astonishing rate. Although these discoveries are widely reported in the press, even well informed readers may want more background than can be given in a typical newspaper or online article, or may be overwhelmed by the huge amount of information available on the Internet. Where can they start? How can they find reliable information? How can students consider whether a career in astronomy may be right for them?

To answer these questions I’ve collected the information and links given below. There's a lot here but it represents only a small part of the information that’s publicly available. I'm sure I've missed important resources, so please send me suggestions for additions to this list, along with any corrections or updates that might be needed for any URLs. 

As a roadmap, here are the different sections:

Observatory news
Astronomy news websites
Astronomy blogs
Online videos about astronomy
Astronomers on Twitter
Astronomy books
Experimenting with images
Visual observing
Exploring the sky with your computer
Citizen science projects
Career advice

Observatory news

For the latest press and image releases in astronomy you can go to websites for various observatories in space and on the ground. Here’s a selection, beginning with the observatory that I work for, Chandra:

Figure 1: A screen capture of the Chandra webpage, taken just after our 15th anniversary in 2014. Credit: NASA/CXC.

These websites contain a lot of background information, e.g. there’s a field guide to X-ray astronomy on the Chandra website and an Explore Astronomy feature on the Hubble website.

Astronomy news websites

Here are a few websites devoted to astronomy news:

More generally you can use Google News to search for new results in "astronomy" or "black holes" or countless other topics of interest. I check the Google News science section regularly.

Astronomy blogs

Here is a small sample of the many excellent astronomy-related blogs that are available:

Brian Koberlein has a blog about different topics in astronomy and maintains an active Google+ account.

Phil Plait, otherwise known as the "Bad Astronomer", has a blog at Slate about science, with a lot of astronomy discussion.

Amanda Bauer, aka astropixie, has a blog about astronomy and life as a scientist.

Emily Lakdawalla has a blog about planetary science. Also check out the other Planetary Society blogs.

Ethan Siegel has a blog, also found at Forbes, focusing on astronomy, with beautiful graphics and detailed explanations. It’s one of my favorite astronomy blogs.

Sabine Hossenfelder has a blog about science, concentrating on physics but with some astrophysics.

Matthew Francis has a blog about science, especially physics, astronomy and science communication.

John Johnson has a blog covering a range of topics including exoplanet research and diversity in science.

Peter Coles has a blog "about the Universe, and all that surrounds it".

Sean Carroll has a blog covering a range of topics in physics and astrophysics, including cosmology. Warning, some equations have been spotted.

Astronomy Picture of the Day (APOD) has a new image and description, with good background information and links, every day.

Online videos about astronomy

Phil Plait is compiling a set of astronomy videos as part of the CrashCourse series.

The PBS program NOVA has a large set of videos about space.

Coursera has over a dozen educational videos on astronomy, and many other fields of science.

David Kipping from Columbia has an impressive set of videos on exoplanets and related research in his Cool Worlds series.

Katie Frey from Wolbach Library at the Harvard-Smithsonian Center for Astrophysics has curated an extensive set of astronomy videos.

Many other videos can be found by searching YouTube.

Astronomers on Twitter

Here’s a list of astronomers and astronomy organizations I follow on Twitter and here are their tweets. Some astronomy communicators are included on this list and there are a bunch of astronomy writers included in my Twitter lists of science writers and science journalists.

Astronomy books

All the above info is free and you're welcome to stick with that, of course. These books are not free unless you find them in a library, so I'll just give a short list:

Your Ticket to the Universe: A Guide to Exploring the Cosmos” is a book by two colleagues of mine, Chandra’s science visualization lead Kim Arcand and Chandra press officer Megan Watzke. I reviewed the book’s science content and wrote a blog post about it.

For people interested in how astronomical data is collected and beautiful images are made, I highly recommend the book “Coloring the Universe: An Insider's Look at Making Spectacular Images of Space”, by astronomy professor and image expert Travis Rector, Kim Arcand and Megan Watzke. For more details you can read my blog post review of this book.

Figure 2: The cover of Coloring the Universe, showing an optical image from the NSF’s Mayall 4-meter telescope at Kitt Peak National Observatory of IC 1396A, a dark nebula more commonly known as the Elephant Trunk Nebula. Credit: T.A. Rector (University of Alaska Anchorage) and H. Schweiker (WIYN and NOAO/AURA/NSF).

For an acclaimed account of exoplanet work, one of the hottest fields of research at the moment, you can read “Five Billion Years of Solitude: The Search for Life Among the Stars” by Lee Billings. It’s had excellent reviews at many places, like one by Dennis Overbye at the New York Times.

Another exciting and fascinating field is cosmology. Harvard professor Bob Kirshner wrote an engaging account of the discovery that the expansion of the universe is accelerating, in “The Extravagant Universe: Exploding Stars, Dark Energy, and the Accelerating Cosmos”. Here’s a sample chapter.

For a fascinating account of the science and history of black hole research, I recommend “Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved” by Marcia Bartusiak.

The hottest field in astrophysics right now involves detecting and interpreting gravitational waves, thanks to LIGO’s ground-breaking and well-described detection of these ripples in space-time. Janna Levin has written an interesting and well-timed account of the work leading up to this discovery, called Black Hole Blue and Other Songs from Outer Space.

For more comprehensive but also expensive books about astronomy, there are several introductions to astronomy for non-science majors beginning college. One of them is “Cosmic Perspective” by Jeffrey Bennett, Megan Donahue, Nicholas Schneider, and Mark Voit. I haven't read it but I know several of the authors are very good.

You can use Google to search for other popular books on astronomy.

Experimenting with images

If you're interested in playing around with astronomical images, there are guides on accessing images, viewing them and using software to combine them into color images. Here’s a guide to creating images from raw data at the Chandra website. See the tutorial at the top. You can create your own color Hubble images, with this extensive guide.

You can collect images of any part of the sky using the Digitized Sky Survey and then follow the instructions given above to make color images. These images are lower in quality than specialized ones from Hubble, for example, but the unlimited field of view is an advantage for large objects.

Figure 3: An image of the Flame Nebula by Chandra image processor Joe DePasquale, using data from the Digitized Sky Survey. Credit: DSS.

Visual observing

For tips on observing the skies, along with a bunch of excellent articles about news and research, you can check out Astronomy magazine and Sky and Telescope magazine. Only a subset of the magazine’s content is available online.

If you have access to a smart-phone or iPad, there are plenty of apps that help in observing the sky, including use of GPS to give a star map of any region you're looking at. Some apps are free and others are not, depending on the sophistication and depth of the database, etc. Several lists of the top apps can be found with Google.

Depending on your location, there may be astronomy clubs nearby. Also, physics and astronomy departments at Universities sometimes hold Open Houses or public talks. Use Google to check for both.

Exploring the sky from a computer

If the skies are cloudy, or if it’s too cold or there are too many mosquitoes, you can explore the sky using your computer. One option is Google sky, either in the web-based application or as part of the desktop program Google Earth. For the latter you have to download Google Earth but it’s more fun to use than the web-based program.

Another excellent program is the World Wide Telescope from Microsoft. This also has a web-based application, but the desktop program is more powerful.

Citizen science projects

Citizen science projects involve voluntary work contributing to active science programs. One motivation is to “help researchers deal with the flood of data that confronts them”. Here are a few of the more popular projects:

Galaxy zoo, involving classifying galaxies. This project was a trendsetter in citizen science for astronomy.

Planet hunters, helping astronomers look for planets using data from NASA’s Kepler mission.

Spacewarps, involving looking for distortion in images caused by gravitational lensing.

Planet Four, involving classifying features on the surface of Mars.

Gravity Spy will help LIGO improve their search for gravitational waves. At the time of writing it’s still in beta test mode.

Those are just a few of the individual projects that are available. The Planetary Society has an excellent web-page summary of different citizen science projects.

Figure 4: A screen capture of the Galaxy Zoo webpage. Credit: Galaxy Zoo.

Career advice

I’ve pulled together some career advice about becoming an astronomer:

Here are a collection of tweets by and responses to astrophysicist Katie Mack on "Advice for Aspiring Astrophysicists" with some tips for aspiring astronomers/astrophysicists in preparing for a possible career in the field.

Duncan Forbes wrote a paper called “So you want to be a professional astronomer” (click on “PDF only” in the upper right).

The Royal Museums Greenwich explains “How to become an astronomer”.

Here is advice from the National Optical Astronomy Observatory on “Being an astronomer”.

Here’s a brief explanation from Caltech about “How can I become an astronomer?”. Note there is a problem with the link to the AAS career brochure at the end. This is the correct link (

Sunday, June 5, 2016

The Value of Good Communication Between Science Journalists and PIOs

Writing is a critical part of science communication, both for general audiences and for expert ones.  Science journalists, public information officers (PIOs) working for universities and other institutions, and scientists themselves – among others – do this writing. I started my career doing research in astrophysics, trying to master the dry, technical writing favored by academic journals. I then changed course, and for the last 13 years I have worked in publicity with NASA’s Chandra X-ray observatory, helping to turn technical writing – that not many people understand – into writing that many people understand. Although I started as an astrophysicist, I’m now closer to being a PIO.

During this second career I’ve developed a keen interest in science writing and science communication, along with the interface between science journalists and PIOs and others working in publicity. Therefore, I have been fascinated by the recent discussion at Undark magazine of “A Looming Rift in Science Journalism” by Aleszu Bajak and “Science Journalists Vs. Public Information Officers” by Paul Raeburn regarding “recent disagreements over who should control the professional group to which they both belong”. The professional group of interest is the National Association of Science Writers, which contains both science journalists and PIOs. However, only journalists can be officials, a controversial point for PIOs, whose membership fees provide a significant source of income for NASW. In his article Raeburn suggests having a splinter organization called The National Association of Science Journalists”. This would solve some problems, but I think it would have some important drawbacks, as I discuss here. [Note, I have never been a member of NASW, but think my outsider’s perspective may be of interest].

Earle Holland, an accomplished, now-retired PIO, explains in one of the many excellent comments to both articles (73 at last count for the Bajak article and 23 at last count for the Raeburn article) that it’s important to keep PIOs and journalists together in NASW so they can learn from each other. I agree. If there is a splinter association for science journalists, I fear that a large fraction of science journalists would leave NASW and they would become even more separate from PIOs than before, possibly increasing friction and a lack of understanding between them.

A personal example of useful science journalist/PIO communication comes from the now-defunct Science Online meetings. I attended the second-to-last meeting in 2013 and listened to many authors and science journalists discussing their craft. A highlight was meeting and working with Nadia Drake, a terrific science writer for National Geographic and other outlets. We led a discussion of how press releases could be improved from a science journalist’s point of view. This led to several blog posts, one written by me and one written by Nadia before the meeting, plus a follow-up post and some useful reflection on how we do publicity with Chandra.

Conflicts of Interest

Here’s another example of useful science journalist/PIO communication. David Dobbs – a writer I have great respect for – commented on Raeburn’s article, writing about the problem he would face if PIOs were to become NASW officers:
“I must leave because some of the publications I write for stipulate that I cannot be a member of organizations in which membership might create apparent conflicts of interest “[COI]. 
This is something that I had never considered before and sounds like an insurmountable problem. However, as Pete Farley pointed out in a follow-up comment:
“…it would be helpful for this conversation if you [David Dobbs] or someone else could provide a real-life sample of the contractual language you describe.”
I agree with Pete Farley that this would be helpful, especially because I have several naive questions – I’m definitely no COI expert – about the details. First, it isn’t clear to me that having one or a handful of PIOs as NASW officers can potentially create a bigger COI than having dozens or hundreds of PIOs as non-officer members of NASW, with their many different employers. In any particular case there might be several non-officer members generating the possible COI rather than just one officer. My point is why wasn’t this a problem before? Sure, the individual officers have more power than non-officers, but Dobbs’ statement above doesn’t make a distinction between different types of members. Is there a threshold of membership status where one goes from not being a potential COI to becoming one? What about members who are at an intermediate level, such as on the NASW board?

Second, I can imagine COI occurring for science journalists being NASW members, both officials or otherwise. For example, what if you see press coverage by other news organizations arguing that a new science result is a breakthrough? However, this story happens to be in a field you know about from previous stories and you find, by talking to your expert contacts, that the result is very likely wrong. Think of arsenic life and Carl Zimmer’s Slate story, for example. You start writing your story but then find that a New York Times or Washington Post writer also did some careful investigation, uncovering important details such as fraud or COI, that you didn’t discover, again casting serious doubt on the original stories. Wouldn’t you want to mention that in your story? But, if New York Times or Washington Post reporters are members of NASW and more specifically if a member happen to be the one who wrote the good investigative story, does that create a COI?

What about working on a story about the commercialization of space and wanting to write positively about the Jeff Bezos-owned Blue Origin? If writers from the Jeff Bezos-owned Washington Post are members of NASW, is that a COI? There are bound to be other examples – people usually work for someone, after all.

These are real questions of mine, rather than rhetorical ones, as I haven’t given this sort of COI much thought. Although these examples are indirect, I’m not sure that anyone can be immune to COI, by joining a large association with a diverse membership. Resorting to full disclosure seems to be a commonly-used remedy to this problem. Do some publications specifically bar the use of full disclosure statements for apparent COI?

Respect for PIO work

I won’t join the “angry turn in some of the comments” as Paul Raeburn puts it, but I often suspect that science journalists think PIOs automatically exaggerate and distort science results. This can sometimes stem from casual rather than malicious remarks. For a personal and minor example, look at the comment-section discussion between Ann Finkbeiner – another writer I have great respect for – and me in a 2012 blog post titled “Trust no one, and other lessons I learned from physics reporters” written by Erika Check Hayden, at The Last Word on Nothing (LWON) blog. Erika Check Hayden mentions a comment by Ann Finkbeiner in her article:
“LWON’s own Ann Finkbeiner says she largely trusts physicists, because they demand highly significant statistical results. But, she adds, “all this believability and trust is called off when the subject has political implications” – as happens frequently with federally funded labs and agencies.”
I work for a federally funded observatory and I responded to Ann’s comment pointing out that there are many different motivations for doing publicity and it’s important to remember that poor publicity can damage the reputations of scientists and institutions. Ann then responded by saying:
“And maybe the problem I’m having is less with the institutions than with the “PR machines” you talk about. Big breakthroughs, farthest whatnots, tantalizing hints of particles – and I know if I call the actual scientist, I’m going to hear, “Well, yeah. That’s sorta 2 sigma.””
 This led to an even longer comment from me – polite but perhaps tinged with self-defensiveness – explaining that we require results to be more significant that 2-sigma to do a release. I also gave more details about the importance of maintaining a good reputation in doing publicity, including the need to have scientists cooperate with us for future stories. I also point out that, like umpiring in sports, publicity efforts tend to be ignored when a good job is done and panned when mistakes are made. This can lead to a distorted view of PIO work. This discussion happened online, but I think it’s even better if it happens in person, at meetings like NASW.

These interactions are why I’d like to see science journalists and PIOs in the same room, even if it’s just once a year. We have a lot to learn from each other. Previously I wasn’t motivated to join NASW but now that I’ve heard PIOs make up a substantial fraction of membership, rather than the tiny fraction I’d assumed, I’ve changed my mind. However, if it’s just PIOs talking to other PIOs, and I don’t have the opportunity to meet fine writers like David Dobbs, Ann Finkbeiner, Paul Raeburn and Aleszu Bajak, my motivation to join would diminish.

Thursday, May 19, 2016

Coloring the Universe: How Beautiful Astronomical Images are Made

Astronomers have made discoveries that have completely changed our view of the Universe and our place in it. Their advanced telescopes have given us a kind of superhuman vision that greatly surpasses what our eyes are capable of in terms of sensitivity, resolving power and wavelength coverage. Their spectacular images rival the beauty of our finest works of art.

The technology and expertise required to obtain these images is just as impressive as their beauty. The book “Coloring the Universe: An Insider's Look at Making Spectacular Images of Space”, released in November last year, gives perhaps the best description available of how these beautiful images are obtained, ranging from a description of the instruments used, to the software techniques adopted to produce the best presentations. Travis Rector, Kim Arcand and Megan Watzke wrote the book.  Travis Rector, an astronomer and one of the world’s best at producing astronomical images, wrote a seminal paper giving a “practical guide” on “how to generate astronomical images from research data with powerful image-processing programs”. Kim Arcand and Megan Watzke are both award-winning science communicators and authors, with extensive experience in disseminating images to a global audience. (In full disclosure, Arcand and Watzke are Chandra X-ray Center colleagues and friends of mine, and I also reviewed a previous book by them, called "Your Ticket to the Universe". In between they’ve written a book called “Light” that is full of gorgeous images from many fields of science.)
Figure 1: The cover of Coloring the Universe, showing an optical image from the NSF’s Mayall 4-meter telescope at Kitt Peak National Observatory of IC 1396A, a dark nebula more commonly known as the Elephant Trunk Nebula. Credit: T.A. Rector (University of Alaska Anchorage) and H. Schweiker (WIYN and NOAO/AURA/NSF).

The text in Coloring the Universe is eloquent and accessible to a wide audience. The book has excellent organization, and each chapter is broken up into easily digestible subsections. Some of the topics covered include a comparison of human vision with telescopic vision and a discussion of what astrophysics can be learned from images. It also explains some details about observing at the world’s largest telescopes and discusses the different kinds of light that we observe.

As expected, the book is full of spectacular images, many produced by Travis Rector and his colleagues, with careful descriptions given in figure captions. It’s striking that many of the ground-based telescope images by Rector et al. are just as beautiful as those made by NASA’s Hubble Space Telescope (HST). For example, here is a HST image showing part of the Veil Nebula, the remains of a supernova in our galaxy:

Figure 2: An HST image showing part of the Cygnus Loop supernova remnant, the expanding remains of a massive star that exploded about 8,000 years ago. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)  

For comparison, here is a ground-based image from a different part of the remnant:

Figure 3: An optical image from the Mayall 4-meter telescope, of the region known as Pickering's Triangle, also part of the Cygnus Loop supernova remnant. This image is rotated by 180 degrees from the one used in the book. Credit: T.A. Rector (University of Alaska Anchorage) and H. Schweiker (WIYN and NOAO/AURA/NSF).
In this case and many others, the much bigger field of view of ground-based telescopes compared to HST can compensate for their much lower spatial resolution, as I described in a blog post in 2014: “What Makes an Astronomical Image Beautiful?, based on a paper by Lars Lindberg Christensen and colleagues. One reason that HST images are often more familiar is that they have a more powerful publicity engine promoting them. Coloring the Universe allows part of this publicity imbalance to be rectified. 

Figure 4: An optical image using the NSF's 0.9-meter telescope at Kitt Peak National Observatory of the Rosette Nebula. Credit: T.A. Rector, B.A. Wolpa & M. Hanna (NOAO/AURA/NSF).

Criticism of astronomical images

Two motivations for writing Coloring the Universe are to demystify the production of astronomical images and indirectly respond to critics. For publicity, beautiful images give astronomy a clear advantage over many other fields of science, as we have found in publicizing Chandra results. There doesn't have to be exciting or important science for a particular result to receive widespread attention. However, not everyone can appreciate such beauty without deep skepticism, and over the years I’ve collected some critiques of astronomical images. (I forgive but I don’t want to forget.) For example, in a New York Times review of an exhibition of solar system images, the writer described the “sub-wooferish whooshes of sound” accompanying planetarium shows using HST images. He followed by writing “Well, the colors are as phony as the sound.” In another example, science writer Charlie Petit described HST images as being “simultaneously dreadfully misleading, worthwhile, and useful”, in one post at the Knight Science Journalism Tracker (now archived at the online magazine Undark). Referring to the famous HST image of the “Pillars of Creation” in a 2007 post, Petit said “The Tracker finds it worth posting in part just to put up the Hubble telescope’s unbelievable image from ten years ago (unbelievable is literally true. Its power came from extensive color tweaking that gives it far more drama than would greet the naked eye).”

It’s not just writers who have been critical. Washington Post writer Joel Achenbach wrote about the mostly negative reactions of astronomers to the Pillars of Creation image (scroll down to the text “From a 1997 story I did in the magazine”). The astronomers criticized the colors used and they also criticized the orientation of the image, as though it’s important for a public audience to maintain the arbitrary astronomer’s convention of North pointing up. These comments were collected almost 20 years and hopefully since then astronomers have gained a better appreciation for the optimal presentation of images for a public audience. I’m not sure this is the case, and for what it’s worth, a 2015 study by Kim Arcand and colleagues of what people think is “real” in astronomical images showed no significant difference between the opinions of self-rated experts and non-experts.

Critics like those described above would gain a better understanding of how images are made and the motivations behind these methods by reading Coloring the Universe. For example, the book contains a chapter called “Photoshopping the Universe: what do astronomers do? What do astronomers not do?” followed by a chapter called “The aesthetics of astrophysics: principles of composition applied to the Universe”. The latter includes a fascinating subsection on why the Pillars of Creation image looks so dramatic.

Responding to the criticism

As Kim Arcand and colleagues explain in discussing the aesthetics of images, the use of color leads to the most questions and comments. As noted earlier, this can result in claims that astronomical images are faked & that they're nothing like what the eye would see. My response to the former is “no!” and my response to the latter is: “why should they be, when telescopes can see so much better than our eyes?” It’s a common fallacy to assume that astronomical images are meant to show what our eyes can see, or might be able to if they were more sensitive. Astronomical images can convey an enormous amount of information, especially when they are not limited by the shortcomings of human vision. For example, images can show narrowband, optical images to pick out phenomena that our eyes are unable to discern. Even more significantly, they can show objects and phenomena in wavelengths that are well beyond the range of human vision, such as X-rays and radio waves.

Figure 5: A composite image of NGC 602, a cluster of bright young stars in the Small Magellanic Cloud, a nearby galaxy. Chandra data is shown in purple, optical data from HST is shown in red, green and blue and infrared data from the Spitzer Space Telescope is shown in red. Credit: X-ray: NASA/CXC/Univ.Potsdam/L.Oskinova et al; Optical: NASA/STScI; Infrared: NASA/JPL-Caltech

As various image experts have explained over the years, such as Megan Watzke, Kim Arcand and Robert Hurt, the colors used in astronomical images are often representative, which means that they are not intended to show how our eyes might see the object, but instead represent maps of the electromagnetic radiation produced at different wavelengths, and with a range of filters. Astronomers often use the term “false color”, but that terminology is misleading for non-expert audiences, as Robert Hurt and others have pointed out. In many cases images simulate what our eyes might see if they were sensitive to very different wavelengths, like Geordi La Forge's visor-enhanced vision in Star Trek the Next Generation.

A good example in Coloring the Universe is the Chandra image of Tycho’s supernova remnant, the remains of a supernova seen on Earth in 1572. Here, the shortest wavelengths are shown in blue, intermediate wavelengths are shown in green and the longest wavelengths are shown in red, in the same order and wavelength order as our vision at optical wavelengths. This use of color helps explain the astrophysics, as the outer blast wave has produced a rapidly moving shell of extremely high-energy electrons (blue), and the supernova debris has been heated to millions of degrees (red and green).

Figure 6: A Chandra image of Tycho’s supernova remnant. Credit: NASA/CXC/SAO

Coloring the Universe gives a much more detailed discussion of the meaning and value of multiwavelength images, and the use of color in making attractive images that give insight into their scientific content.

Without giving too much away, here are a few other highlights of the book:

  • It shows a sense of humor, e.g. in describing how colors should be used appropriately it notes that people in images wouldn’t be colored green “unless you’re in Roswell, New Mexico”. Also, since optical astronomers observe (hopefully) all night, the authors note, “like vampires we sleep during the day” and “Fortunately, we don’t sleep in coffins”. 
  • I liked the use of raw images to show what telescopes collect before processing has been done, and how calibration and multiple exposures correct for changes in charge coupled detector (CCD) sensitivity and gaps between CCDs.
  • It gives an excellent description of the history of astronomical images and their dissemination, including HST’s observations of Jupiter and Shoemaker-Levy in 1994 at a pivotal time for the production and dissemination of images. The World Wide Web started in 1991 but its use was limited until the Mosaic web browser was introduced in 1993. Another big step was the release of layering capabilities in Photoshop in 1994, allowing sophisticated color composite images to be created.
  •  An authoritative description is provided of the important role that images play in publicity, including the establishment of programs like Hubble Heritage, providing the opportunity to gather beautiful images that professional astronomers might have missed.

I’ll end with an excerpt from the summary of Coloring the Universe:

“In this book we’ve talked about the complex process of converting what the telescope can see into something we humans can see. It’s a fundamental challenge because our telescopes observe objects that, with a few exceptions, are invisible to our eyes. That is of course the reason why we build telescopes. There would be no point in building machines like Gemini, HST and Chandra if they didn’t expand our vision. Astronomers use telescopes to study and understand the fundamental questions of how we came to be: from the formation and fate of the Universe; to the generation and function of galaxies; to the birth, life and death of stars inside galaxies; to the planets and moons around these stars; and to the origin of life here and possibly on worlds beyond our own.”

The text continues with an eloquent summary of the principles and motivation behind the production of astronomical images, which you’ll have to purchase the book to enjoy. I highly recommend that you do so, to savor the gorgeous images Coloring the Universe contains and to appreciate the ingenuity involved in producing these images.

End note: While waiting for Coloring the Universe to arrive in the post, you can watch this excellent talk by Jayanne English from the University of Manitoba, titled “Are images of space realistic?”