For a few Hubble press releases, our scientific visualization group provides a reminder of the three-dimensional nature of the imagery with a virtual journey across space. The most recent is an exploration of a star-forming region known as S106. The movie takes the viewer past the foreground stars and descends toward the gaseous landscape of the nebula.

When creating the 3D models for these visualizations, we utilize scientific knowledge where available. In the case of S106, a couple of research papers outlined the hourglass shape of the nebula, as well as the directions of the central outflows. Other aspects required using scientific intuition, such as the statistical model used to place stars in front of and behind the nebula. When neither knowledge nor intuition is available, we use artistic license to fill out details, while diligently striving to remain scientifically plausible.

Folks are sometimes surprised when I tell them that our goal is not strict scientific accuracy. The main problem is that the universe is incredibly big and sparsely populated. Distances usually must be significantly compressed to create more engaging visualizations. In other situations, the scales in length, time, temperature, density, etc., can be, well, astronomical. Our goal for these visualizations is not textbook instruction, but to remind people of the 3D structure inherent within the Hubble imagery.

Experience has shown that these visuals can have a powerful effect. How we imagine the universe plays a strong role in how we interpret and understand new information about astronomy. These visualizations not only explore celestial wonders, but also help set one’s “mental model” of the cosmos. All it takes is looking from a different perspective.

Hubble floats 350 miles (560 km) above Earth.

Near the beginning of most of my talks about the Hubble Space Telescope, I remind the audience about Hubble’s location in space. I emphasize not how far away Hubble is, but that Hubble’s orbit is much smaller than most people imagine.

Earth’s atmosphere is traditionally considered to extend to 60 miles (100 km) above the surface. In truth, the thermosphere and then exosphere layers extend beyond this height to thousands of miles, but they are extremely low-density layers.

Because the main objective is to get Hubble above the blurring effects of the atmosphere, its 350-mile-high (560 km) orbit does the job.

But, compared to a planet 7,920 miles (12,740 km) in diameter, Hubble’s orbit is not that impressive. Note that communications satellites in geosynchronous orbit are about 65 times higher than Hubble.

I was reminded of this topic when, on Dec. 12, 2011 the Dawn spacecraft reached its lowest-level orbit around the solar system’s second-largest asteroid, Vesta. Dawn’s low, altitude-mapping orbit averages only 130 miles (210 km) above the surface. Though Vesta is comparatively small at 330 miles (530 km) in diameter, it is still cool to note that Dawn is closer to Vesta than Hubble is to Earth.

While we are accustomed to weather satellites studying our planet in detail, we now have a satellite orbiting and observing an asteroid. Dawn will do so for about 10 weeks before migrating back to a higher orbit.

Then, in July 2012, Dawn will depart Vesta en route to the solar system’s largest asteroid, Ceres, for a 2015 arrival. The images and discoveries from this mission are and will continue to be spectacular. We are truly examining the asteroid belt in an up-close and personal way.

Lunar eclipse, Dec. 10, 2011 CREDIT: Michael R. Perry

Because the Hubble Space Telescope produces so many spectacular images of the universe, it can be easy to over-generalize and assume that Hubble is the best telescope for any astronomical observation. Hubble does have some major restrictions: it can’t observe the Sun, track fast-moving objects, or detect x-ray light or radio wavelengths. In addition, there are some celestial observations where there is just no substitute for the experience of seeing it with your own eyes.

I had the fortunate experience of being a guest lecturer on a cruise ship during the Dec. 10, 2011 total lunar eclipse. During the prior week, I gave a presentation on eclipses and ran some evening star-gazing sessions. The skies in the open ocean were beautiful, although the light of the nearly full moon masked a few celestial highlights from our view.

The lunar eclipse began at 3:33 a.m. local time. As you might expect, I was alone on deck. For the first  hour or so, the Moon passed into the fainter penumbra of Earth’s shadow, and it was unimpressive. But as the Moon entered the darker umbra, and slowly passengers joined me, the observing grew into an event. The window shade of Earth’s shadow descending across the Moon piqued curiosity and excitement. And, as the Moon darkened, many stars that had been unobservable on previous nights appeared.

Around 5:45 a.m., the eastern horizon began to brighten with the pre-dawn glimmers of sunrise. The final sequence was a competition between the Sun and Moon for our attention, twilight versus eclipse. When the lunar eclipse became total, just after 6 a.m., the crowd of 40-50 greeted it with heartfelt applause for the celestial showcase.

This experience was truly wonderful and one that Hubble just could not have captured. While I encourage you to explore HubbleSite for all the images and discoveries contained therein, I also hope that it inspires you to use your eyes, or a pair of binoculars, and do a little exploring for yourself.

Hubble astronomers watch the first impact of comet P/Shoemaker-Levy 9.

A 1632 oil painting by Rembrandt, "The Anatomy Lesson of Dr. Nicolaes Tulp"

Novelist Edith Wharton wrote once: “In spite of illness, in spite even of the archenemy sorrow, one CAN remain alive long past the usual date of disintegration if one is unafraid of change, insatiable in intellectual curiosity, interested in big things, and happy in small ways.”

Indeed, human curiosity about the cosmos and about “what does it all mean?” has always exceeded that needed for mere survival or improvement in the quality of life. Curiosity is the ultimate driver of scientific exploration, and the key to creativity.

In July of 1994, the fragments of a comet – comet Shoemaker-Levy 9 – collided with Jupiter. Almost every telescope on the face of the Earth and in orbit (including Hubble), was directed to observe the collision. At the Space Telescope Science Institute, more than a dozen astronomers gathered around a computer screen, eager to watch the impact of the first fragment. Everybody was curious to observe directly, for the first time, the results of an extraterrestrial collision between solar system objects.

A photographer took a picture of the event. What is most remarkable about this photograph is that it captures the essence of curiosity. As soon as I saw it, the photo reminded me of a painting by Rembrandt, known as “The Anatomy Lesson of Dr. Nicolaes Tulp.” In that painting too, Rembrandt’s focus is not on the corpse being dissected, but rather on the curiosity expressed by the attending doctors.

As Edith Wharton so insightfully observed, as long as we keep our intellectual curiosity alive, there is a clear path forward.

Spectral lines are inscribed in laser light across the Hayden Planetarium at the American Museum of Natural History.

For a few weeks this fall, both the Maryland Science Center in Baltimore and the American Museum of Natural History in New York were graced with a unique science and art exhibit. In a public presentation of astronomy data, Hubble spectra were etched with a high-power green laser on the facades of these two museums.

At first glance, the laser art exhibit is just a series of green squiggly lines. It looks more like a heartbeat or earthquake monitor than anything to do with Hubble or the universe. However, a little explanation can illuminate that connection and convey the deeper meaning behind it.

Hubble is well known for its amazing images, but about half of Hubble’s observations and discoveries come from examining an object’s spectrum. Hubble’s instruments disperse the object’s light into its component rainbow of colors. By studying the brightness of the light at each color, astronomers can deduce properties like temperature, composition, and motion. The graphs of spectra are the squiggly lines featured in the laser art exhibit.

Importantly, spectra are the crucial observations for very distant galaxies in the universe. These galaxies are so far away that even Hubble sees them as small blobs of light. Spectra provide the details that help us understand their characteristics and determine their distance.

And, at billions of light-years away, we see these galaxies as they were billions of years ago. These spectra are information gleaned from across both space and time, which led the artist Tim Otto Roth to name his laser presentation “From the Distant Past.” As he puts it, these graphs are “minimalist representations of some of the most distant objects in the universe.”

To an astronomer, it’s refreshing to insert spectra into the image-dominated public conversation about astronomy. Hubble science greatly depends on spectra to provide vital information about our universe, yet it is hard to present adequately in a press release. When you look at this laser exhibit, see past the green squiggles, and recognize spectra: the unsung hero of Hubble discoveries.

NASA's Great Observatories, four space-based missions designed to conduct astronomical studies over many wavelengths

As an astronomer, I have many tools at my disposal to study the universe and tackle tough questions. There are hundreds of ground and space-based telescopes that we point to the cosmos, powerful computers that analyze the images, and a wealth of knowledge on the internet and in libraries that both describe our current understanding and provide the mathematical framework to solve problems.

While the current suite of tools will continue to enable new research on a wide range of astronomical questions, history teaches us that major discoveries and breakthroughs come about when we apply new technologies to create unprecedented resources. For these reasons, I can hardly wait to see the first images from the James Webb Space Telescope.

Almost 100 years ago, astronomers built the first large, modern telescopes on the ground. Telescopes like the Hale and Hooker telescopes at Mt. Wilson Observatory, with their 60” and 100” mirrors to capture faint light, provided a new level of clarity in characterizing nearby stars in our galaxy, and led to the breakthrough discovery that our Sun is not located near the center of the Milky Way galaxy. These technologically advanced telescopes also enabled Edwin Hubble to prove that our galaxy itself was not alone in the universe, and that others like it were also wandering in space.

As astronomers produced larger and stronger telescopes, our ability to push beyond the Milky Way  increased greatly, and we began to understand the vast nature of our universe and the diversity of galaxies within it.

NASA enabled a new leap forward in our understanding of the universe by developing the first big telescopes in space, such as Hubble and Spitzer. This Great Observatories program represented a bold new vision to expand our astronomical discoveries.

Hubble, launched over 20 years ago, has revolutionized almost every field of astronomy and planetary science, reshaped our knowledge of the universe and our role within it, and brought enthusiasm about space science to the general public, students, and educators. I personally owe a big thanks to Hubble. When I started my postdoctoral researchship in Santa Cruz, CA, in 2004, I was awarded a “Hubble Fellowship.” This research grant allowed me extreme flexibility and resources to pursue the research that I wanted, and was a great springboard for launching me to my career path.

Nowadays, I use Hubble both for my own research and to educate the public about the amazing discoveries that it has brought forth. Just a few weeks ago, I was showing pictures from Hubble to 500 kids in Long Beach, CA. It is one of the reasons that I love astronomy so much.

In the next few years, all of the Great Observatories may reach their limits. Astronomy is a science that is limited by the quality of the observations, and those observations are limited by how much light our telescope’s mirrors can collect. Hubble and Spitzer have demonstrated that many of the most important questions that we face in astronomy today can be answered by designing a powerful new telescope that combines Hubble’s razor-sharp vision with Spitzer’s infrared sensitivity.

To enable this next leap forward in telescopes, NASA has teamed up with the European Space Agency (ESA) and the Canadian Space Agency (CSA) to build the successor to the Great Observatories, the James Webb Space Telescope (JWST). As both an astronomer and as the Deputy Project Scientist for this mission, I feel very fortunate to be a part of this important scientific and technological achievement.

JWST, or “Webb” as we call it, will significantly overlap with Hubble and Spitzer in the range of wavelengths it sees, (red optical, near infrared, and mid infrared), and, most importantly, be more than 100 times as powerful as these Great Observatories. JWST includes many different types of cameras, spectrographs, and coronographs, to enable a diverse range of scientific investigations for astronomers. It is exactly what we have been waiting for!

Astronomers like myself have been excited about JWST for over a decade, and the project has now completed several important milestones. All 18 of the primary mirror segments of JWST (which span 21 feet when put together) are completed. All of the science instruments on the telescope are also making excellent progress. The telescope will soon enter a phase of assembly and testing, where all of the various completed parts are put together and tested as a whole. This ensures that everything works correctly in space, since astronauts will not be able to “service” JWST as they did for Hubble.

Once JWST launches in 2018, astronomers will embark on several new scientific projects that have not been previously possible. In my opinion, some of primary science goals of JWST for astronomers are intimately tied to fundamental questions that humankind has asked itself for centuries.

I grew up in a small town called Quesnel in central British Columbia, Canada, about 8 hours north of Vancouver. We had a beautiful view of the night sky. When I would stare up at the cosmos, I would ask myself how the universe began, how it came to be littered with all of these stars and galaxies, and whether there is life elsewhere on another planet.

JWST will reveal the first stars and galaxies in the infant universe, will teach us how these galaxies evolved to form beautiful systems like the Milky Way, will uncover newborn stars and planets in our own galaxy, and will examine the atmospheres of planets outside our solar system for the signatures of water vapor. Where there is water, there may be life!

And yet even with those goals, if Hubble is any example, JWST’s most amazing discoveries will actually be things that we cannot even imagine today.

Read all about the history of ground and space-based telescopes at our Amazing Space site “Telescopes from the Ground Up.”

In response, I usually tell them an anecdote about one of the greatest scientists of all time, Sir Michael Faraday, whose pioneering studies in electricity and magnetism opened the door for modern technology.

William Gladstone, chancellor of the exchequer (the equivalent of minister of finance), visited Farady in his lab and asked him about the practical worth of electricity. “Why, sir,” Faraday responded, “there is every probability that you will soon be able to tax it!”

When one deals with basic research, as is the case with astronomy, it is virtually impossible to know in advance to which practical applications that research might lead. The fact is that the very first “Laws of Nature” (e.g. the laws of motion and of gravity) were formulated by Newton on the basis of astronomical observations. Those are the laws on which our technology is ultimately based.

In addition, astronomical phenomena may be used directly for some fundamental measurements. We know today, for instance, that pulsars — rapidly rotating neutron stars — are the most accurate clocks in nature. One day in the not-too-distant future, they may replace atomic clocks in providing our standard of time.

Einstein’s theory of General Relativity, which was both motivated and tested by astronomical observations, is already crucial for the operation of GPS systems. Observations of the Sun provide vital information about potential disruptions in communications and power grids.

At the end of the day, however, research in astronomy and astrophysics is motivated by human curiosity. We want to understand the origin, workings, and fate of universe, and to appreciate our place within it. Astronomy enables us to answer questions that we didn’t even know how to ask 100 years ago.

These four Hubble images of Neptune, taken during the planet's 16-hour rotation, exhibit a full view of the planet.

On July 12, 2011, we celebrated what some have called “Neptune’s birthday.” Hubble released four pictures of the planet to commemorate Neptune’s first full orbit since its discovery on September 23, 1846. On that day, Johann Galle at the Berlin Observatory found Neptune based on the mathematical prediction of a French astronomer, Urbain Le Verrier. Because Neptune takes almost 165 years to complete its orbit around the Sun, a lot has happened during the Neptunian year since we learned of the planet’s existence.

However, calling this a “birthday” smacks of anthropomorphism and a human-centered view of the universe. Neptune has been around for billions of years, and no one can say when it was “born” to any precision better than many millions of years. In the grand scheme of things, does it really matter that we finally got around to noticing Neptune on that day? Plus, it is fun to note that Neptune had been seen before that day, but not recognized for the planet it is.

A few months earlier, in England, James Challis was actually searching for the new planet, based on the prediction of John Couch Adams, not Le Verrier. After the discovery was announced, it was uncovered that Challis had observed Neptune twice, but had not analyzed the data enough to find it. The national rivalries were strong in those days, and so was the outcry that England had “lost” the discovery to France and Germany. The full story of Neptune’s discovery makes for one of the best scientific soap operas of all time (try to find the out-of-print book “The Discovery of Neptune” by Morton Grosser).

Going back further, the earliest observations of Neptune date back to some of the earliest observations with a telescope. In December 1612 and January 1613, Galileo was following the motions of Jupiter and its four large moons, which he had discovered a couple years earlier. Neptune was in his field of study, and was noted by Galileo as seeming to move relative to a nearby star, yet not recognized as a planet.

All in all, anytime is a good time to release more Hubble pictures of Neptune. Since its the seasons last over 41 years each, we’re getting a drawn-out and detailed view of the emergence of summertime in Neptune’s southern hemisphere.

Four moons are seen orbiting Pluto, June 28, 2011.

On July 20, 2011, NASA announced that Hubble had discovered another moon orbiting Pluto. This new moon, temporarily named P4, adds to Hubble’s previous discovery of the moons Nix and Hydra, announced in 2006. The press release called P4 the fourth moon around the dwarf planet Pluto. That description provoked a variety of responses.

First, some folks felt that the description devalued Pluto. If it has four moons, doesn’t that qualify Pluto as a planet? Remember that Pluto was called a planet when it was discovered in 1930. In 2006, the IAU changed its classification to dwarf planet. Today, most astronomers refer to Pluto as a Kuiper Belt Object (KBO).

The presence or absence of moons does not affect an object’s classification, as several types of objects have moons. While most planets have moons, note that Mercury and Venus have no moons. Other dwarf planets have moons, like Haumea, which has the two moons Hi’iaka and Namaka. Other KBOs have moons, such as 1998 WW31, tracked by Hubble in 2002. Even small asteroids can have moons, as evidenced by Ida and its moon Dactyl. From these examples, one can see that having moons is neither a necessary or sufficient condition to call an object a planet or a dwarf planet or a KBO or an asteroid.

Second, some other folks felt that the description devalued Charon. Because Charon has significant mass compared to Pluto, it is not really correct to say that Charon orbits Pluto. Instead they both orbit a point that, while closer to Pluto than Charon, is outside the volume of either (here is a rough illustration of their orbits). Many people consider Pluto/Charon to be a double dwarf planet. Hence, they consider P4 to be the third moon of Pluto/Charon.

My view goes just a bit further. I find the definition of dwarf planet to be entirely useless. It defines a category for which I see no purpose – it doesn’t add to our understanding of either the structure or development of the solar system. The proper classification is that Pluto/Charon is a double Kuiper Belt Object with three moons.

And that classification doesn’t mean Pluto is somehow considered worthless. I can’t wait until the New Horizons mission gets to Pluto/Charon in 2015. Three satellites around two KBOs makes for one interesting system to study.

Recently, I found myself in a different role, as the chief scientific and local organizer for one such meeting, a major international conference. The meeting brought together almost 200 astronomers from across the world to share in “Frontier Science Opportunities with the James Webb Space Telescope.”

The process of organizing a big meeting such as this begins more than nine months before the actual meeting. Late last year, we formed a “Scientific Organizing Committee” (SOC) consisting of a dozen members of the astronomical community, including myself.

We decided that we would like to jump-start a discussion of high impact science programs that the James Webb Space Telescope (JWST) could perform when it launches later this decade. The goal is to get astronomers actively thinking about the telescope, so we can jump into the science quickly when it’s ready.

Next, the SOC selected about a dozen speakers and invited them to the meeting to share the diverse research topics that Webb could address. With this list of experts posted, we opened up registration in January 2011. The community responded with a flood of interest. We received dozens of requests for contributed talks and presentations. Over the past few months, I have been involved in scheduling the meeting, organizing the discussion sessions, and planning a dinner for our guests at the Maryland Science Center with a screening of the “Hubble 3D” IMAX movie.

The payoff for all of the work came when the first science talk began. The topic was how Webb could improve our understanding of the atmospheric structure of nearby planets, such as Uranus and Neptune. The next talk told us how Webb could enable discovery of the first stars that exploded in the universe, through imaging of “Pair Instability Supernovae.” We were off to a good start! With the first two talks, we had covered a range extending from the nearest objects in the universe to some of the farthest away.

The conference continued for three full days and paved the way for a very exciting Webb science case that touches on many different topics: studying extrasolar planets and their atmospheres; learning how galaxies come together by mapping the ages, motions, and chemical nature of their stars; and discovering the first galaxies that emerged when the universe was in its infancy. Although some of these science goals are similar to those defined for Webb years ago, the presentations at the meeting provided a rejuvenated interest in these endeavors. In fact, many of the science cases have become stronger in light of recent research in these fields.

We discussed the criteria astronomers would use for future discoveries with Webb. If we find a planet with water vapor in its atmosphere, what kind of other criteria would be needed to declare that planet potentially life-bearing? When we’re looking at the most distant stars in space, what litmus tests must they pass before we can determine that we’re looking at the universe’s very first stars?

“Frontier Science Opportunities with JWST” also revealed that astronomers have a lot of homework to do before the telescope launches into space. Participants emphasized the fact that we have precious resources in astronomy right now that could be used to observe the types of exotic objects Webb will study. We could make those observations now and have a wealth of additional data for astronomers to study in conjunction with the eventual Webb observations – just as space telescopes like Chandra and Spitzer have been used to provide complementary observations for Hubble. One of my goals for the next few years will be to investigate this further and come up with a plan to ensure that we fully capitalize on our existing missions to make Webb that much more successful.

Want to know more? All of the talks and Powerpoint slides for “Frontier Science Opportunities with JWST” are posted at http://webcast.stsci.edu/webcast/.