Speaking of Hubble...

Curiosity: An Augmented Reality Experience

July 26, 2012 by Alberto Conti
NASA's Spacecraft 3D is an augmented reality (AR) application that lets you learn about and interact with a variety of spacecraft that are used to explore our solar system, study Earth, and observe the universe.

NASA's Spacecraft 3D is an augmented reality application that lets you learn about and interact with a variety of spacecraft.

Over the past 30 years, many of us have enjoyed entertaining and challenging video games. Do you remember the classic Pong? Space Invaders? Playing games is an important part of life, after all.

The number of transistors in modern computers has increased over 2 billion times since the late 70s. As a result, computing power has increased by more than six orders of magnitude (2 million times) and has made possible the technological revolution we are living in today.

Today, we can play even very complex video games on our smart phones. However, to me the most remarkable development is how much more photo-realistic computer graphics have become. It will not be long before it will be hard to tell the difference between artificial and real landscapes.

As the barriers of photo-realism rapidly drop, our expectations of possible interactions with machines rise. Old preconceptions about where our reality ends and where a virtual reality starts are rapidly changing. Commercially available 3D televisions are quickly adding a third dimension to our viewing experience, but lately a new trend has emerged: augmented reality. This new technology seems to finally successfully blur the line between what’s real and what’s computer-generated by enhancing what we see, hear, and perhaps soon feel and smell. Augmented reality is basically starting to integrate all available pixels on all your devices into real-world environments.

Augmented reality isn’t the fully immersive, completely computer-generated environment produced by virtual reality; instead it’s an at-times-subtle augmentation of your real world. Augmented reality adds graphics, sounds, and visual feedback to the natural world as seen from your own device’s camera. Google’s Project Glass is an example of what we can expect to see in just a few years.

It comes as no surprise that this augmented reality movement is strongly driven by the game and smart phone markets, which after all control most of the pixels we have access to on a daily basis. The end game is to fundamentally change the way we perceive our world by giving our own senses access to information available only to machines.

On July 11, NASA entered the augmented reality arena for smart phones by releasing an augmented application that brings some of the agency’s robotic spacecraft to life in 3-D on iPhone and iPads. Spacecraft 3D is a simple application that allows anyone with an iPhone or iPad (Android version coming soon) to experience a three-dimensional model of NASA’s spacecrafts in high definition.

In this first iteration, Spacecraft 3D showcases the Mars Science Laboratory rover (also known as Curiosity) which is scheduled to make it’s incredible landing on the surface of Mars on August 5. So, grab the app and get familiar with the rover on a virtual desktop near you.

Not in a Billion Years

July 20, 2012 by Frank Summers
After the Milky Way-Andromeda merger, our Sun will likely be tossed into a looping orbit around the newly formed elliptical galaxy.

After the Milky Way-Andromeda merger, our Sun will likely be tossed into a looping orbit around the newly formed elliptical galaxy.

In the recent Hubble press release about the collision between our Milky Way galaxy and the Andromeda galaxy, we provided some artistic illustrations of what a future night sky might look like. It shows the fantastic sights as Andromeda approaches, smashes through, and eventually merges with our galaxy.

Although it may seem like splitting hairs, I note that we specifically did not say that those illustrations show what Earth’s night sky would look like. There are three reasons for this.

First, those illustrations were motivated by views from a computer simulation. The viewpoint inside the simulation was held fixed in space at the Sun’s current location relative to the center of the galaxy. Though the Sun continually orbits the core of the Milky Way, a fixed location provided a more easily understandable sequence of images.

Second, the Sun’s orbit in the galaxy will probably change greatly during the collision. Our star could get flung far into the outskirts of the Milky Way, drop deep into the core of the galaxy, or do both on a spirograph-like orbit. Almost all scenarios greatly change our night-sky view.

Third, and most important, while Earth should still orbit the Sun in 4 billion years, it probably won’t be habitable. Our Sun is slowly getting hotter as it ages. According to calculations, in about 3 billion years the Sun will be hot enough that Earth’s oceans will evaporate and its atmosphere will escape. Human life on the surface of our planet will not be feasible without planet-scale engineering efforts.

The illustrations show what a night sky might look like, but the view seen by a future human civilization is guaranteed to be different. Still if our species survives to see it, it will be awesome to have two galaxies stretched across the sky. Although, as an astronomer, I can’t help but imagine how confusing it might be to detangle the star and galaxy motions.

Only Two Cosmic Disasters Are Certain

July 13, 2012 by Ray Villard
A Sun-like star ends its life by ejecting layers of gas into space.

A Sun-like star ends its life by ejecting layers of gas into space.

The sardonic proverb “nothing is certain but death and taxes,” can now be recast for the cosmos.

The inevitable collision of the Andromeda galaxy with the Milky Way is one of only two astronomical predictions with which we can be absolutely certain. The other is the death of our Sun.

There’s wonderful irony in the presence of Internet soothsayers predicting numerous impossible cosmic disasters this year, simply because the ancient Mayan Calendar “ends” in 2012, when we have real cosmic disasters to concern ourselves with in the future … even though the Milky Way’s “big bang-up” with Andromeda won’t happen for another 4 billion years, and the Sun won’t burn out for another 6 billion years.

In contrast, the eventual galaxy collision is solidly predictable. It will be the result of the inexorable pull of gravity between two heavyweight “island universes,” each weighing over 1 trillion times the mass of our Sun.

The Hubble Space Telescope’s detailed observations show that the Andromeda galaxy is heading straight toward us. Nearly 100 years ago, astronomers knew that Andromeda was coming this way, but they didn’t know if it would be a glancing blow or head-on collision. Hubble astronomers settled the question.

Ever since the nuclear fusion processes taking place deep inside the Sun have been understood, astrophysicists have been able to calculate the Sun’s age and longevity.

We know with absolute certainty that the Sun will burn out 6 billion years from now, leaving Earth a cold, barren cinder. And the Sun’s fate can be extrapolated to every other star in the universe. The very last star burns out 100 trillion years from now.

Hubble shows us the dramatic details of what happens when a Sun-like star burns out. Colorful, hot gases are ejected into space to form bubbles, butterfly shapes, and hourglass shape. We know that the Sun will flame out in a similarly spectacular fireworks display. It will mean the death of Earth, but may simply be another space photo in some extraterrestrial creature’s astronomy textbook 6 billion years from now.

Beyond these two irrevocable events, all other cosmic disasters are simply probabilistic rather than deterministic. You might want to take out homeowners’ insurance against them, but you can still hold out hope you’ll never need to cash in on your policy.

The broad spectrum of cosmic disasters bandied about on the Internet stretches from possible, to improbable, to utterly impossible.

Statistically a planet-killer class asteroid should whack us in less than 100 million years.

A nearby supernova could irradiate Earth within 250 million years.

Chaos theory allows for a small probability that the planets will become unstable in their orbits in a few billion years, and Earth will collide with Mars.

But by then Earth’s oceans will have been evaporated away under the warming sun.

There is an infinitesimally small chance a bypassing star or rogue black hole would run into the Sun. And those odds would slightly increase during the Milky Way collision.

The technological prowess of our civilization should allow humanity to avert many of these disasters. Frankly, we deserve to become extinct if we don’t have the wherewithal to come up with the money and technology to protect Earth from maundering asteroids.

What’s more, straightforward Newtonian physics could be applied to move Earth farther from the aging and warming Sun by setting up an interplanetary pinball game where we rob momentum from asteroids to widen Earth’s orbit.

Though we have evidence for the beginning of the universe, we can only speculate how it will  –or might –end someday.

Dark energy is the wild card here, because if it is unstable over time (which it doesn’t seem to be), it could rip the universe apart or even implode space and time.

Quantum physics allows for a “phase transition” where the universe abruptly ceases to exist into a wave of nothingness that propagates across space at the speed of light.

The Milky Way/Andromeda collision is unique in that it is probably the farthest we can extrapolate into the future with any certainty.

This event needs a name that’s as catchy as the Big Bang. Some ideas from my friends include: The Big Bang-up, The Milky Splay, The Milky Shakeup, and The Big Milky Spill.

But there’s no sense crying over it …

SKA: The Sound of Data

July 6, 2012 by Alberto Conti
Artist's impression of the SKA dishes. CREDIT: SKA Organisation/TDP/DRAO/Swinburne Astronomy Productions

Artist's impression of the SKA dishes. CREDIT: SKA Organisation/TDP/DRAO/Swinburne Astronomy Productions

SKA is coming. No it’s not the Jamaican music genre of the late 50s, even if it might sound like music to radio astronomers’ ears. SKA is the Square Kilometre Array, a radio telescope currently in development. SKA is set to revolutionize radio astronomy, perhaps in the way the Hubble Space Telescope did for the visible-light portion of the electromagnetic spectrum.

SKA, as the name implies, will be able to collect radio waves over approximately one square kilometer or a million square meters. The signal from thousands of antennas spread over about 1,900 miles (3,000 km) will work together as one gigantic, virtual instrument capable of extremely high sensitivity and resolution, continuing radio astronomy’s tradition of providing the highest-resolution images in all astronomy. Coupled with its operational frequencies, SKA’s sheer size will make it 50 times more sensitive and 10,000 times faster at surveying the sky than any other radio telescope currently in existence. In addition, thanks to new technological advances, SKA will even enable multiple users to observe different pieces of the sky simultaneously!

This amazing instrument is being designed to address some of the most pressing questions in astrophysics, fundamental physics, cosmology and particle astrophysics:

  • When and how were the first stars formed?
  • What is the nature of dark energy and dark matter?
  • What and where are the conditions for life?
  • Was Einstein correct about General Relativity?
  • Where does cosmic magnetism come from?

The James Webb Space Telescope will also address some of these questions, and astronomers are already thinking about how these two observatories can be used together to provide deeper insight into cosmic objects. With such broad scientific objectives, SKA has the potential of truly transforming the exploration of the universe at radio wavelengths. However, the astronomical community faces huge challenges stemming from its construction and from the sheer volume of data it is expected to produce.

To maximize the potential for new discoveries, SKA needed to find a suitable site. The southern hemisphere of our planet seemed an ideal place given its minimal radio interference, and last month a split decision was announced by the SKA organization members — Australia, China, Italy, the Netherlands, New Zealand, South Africa and the UK — to build core receivers in South Africa, Australia and New Zealand.

Australia and New Zealand will host its core site at the Murchison Radio-astronomy Observatory (MRO) in Western Australia, with the most distant stations located in New Zealand. South Africa will host another core site located about 75 km north-west of Carnarvon, with distant stations in Botswana, Ghana, Kenya, Madagascar, Mauritius, Mozambique, Namibia and Zambia. Each site in Australia and South Africa will host SKA arrays at increasing distances and decreasing density. The densest region, known as the core, will contain approximately half of the total collecting area of the SKA arrays in a circle of just over 3 miles in diameter (about 5 km). A mid-region extending to about 112 miles (180 km) from the core will host arrays placed randomly at an ever-decreasing density from the center. Finally, an outer region extending to about 1,900 miles (3,000 km) from the core will comprise five spiral arms along which dishes, grouped into stations of 20, will be located. The separation of the stations increases towards the outer ends of the spiral arms in a pattern, borrowed from nature, which maximizes spatial coverage (see how and why in this great talk by Dr. Rick White).

Layout of the SKA antennas on the ground. CREDIT: SKA Organisation/Swinburne Astronomy Productions

Layout of the SKA antennas on the ground. CREDIT: SKA Organisation/Swinburne Astronomy Productions

The first phase of construction will take place from 2016 to 2019, with the goal of providing about 20 percent of the total collecting area at low and mid frequencies. This will ensure that SKA can start operating well before full construction is complete. The rest of the construction will be finished by 2024.

However, there is another dimension to the challenge that is SKA. Such a large number of arrays (potentially up to 4,000), with the need to sample celestial phenomena at ever increasing spatial and temporal resolution, will require very high performance central computing engines and a capacity that rivals the current global Internet traffic. In fact, once the raw data is processed, SKA will be able to produce in a single year an amount of data comparable to all the traffic of the entire Internet in 2011!

This is entirely new territory. This huge increase in scale requires a revolutionary approach — not only to traditional radio telescope design, but also to data storage and handling technologies, and computational resources.

SKA will require numerous advances in computing technology:

  • Computers capable of 1,000 more computations per second than current supercomputers
  • Software that mimics the behavior of our brain with millions of connections and billions of computations
  • Improvement in power efficiency to allow large number of machines to run at full capacity constantly

SKA’s future therefore hinges on the project’s ability to forges partnerships with both research and industry leaders in high-performance computing. The payoff for industrial partners seems obvious: an ideal test bed for systems that process large volumes of data from geographically dispersed sources with extreme energy requirements. The hope is that SKA’s spinoffs will spur technology development in areas like high-performance computing and large data-storage warehouses, but also renewable energy generation.

Let the music start: SKA!

When Galaxies Collide; Stars Don’t

June 28, 2012 by Frank Summers
Arp 148 is a unique snapshot of an ongoing collision.

Arp 148 is a unique snapshot of an ongoing collision.

In a recent blog post, I discussed the collision between our Milky Way galaxy and the Andromeda galaxy. In about four billion years, the two vast, spiral shapes will combine and transform into a single elliptical galaxy via a powerful gravitational smash-up.

News of the awesome collision prompted many to ask about what happens to the stars within the galaxies. In particular, what might happen to our Sun and the planets around it.

The good news is that when galaxies collide, the stars inside them won’t crash together.

To understand why, one has to recognize just how far apart the stars are. It’s easiest to explain with a scale model.

Suppose the Sun were the size of a baseball. I live in Baltimore, so let’s imagine this baseball is located at home plate in Oriole Stadium.

One of the stars nearest our Sun is Alpha Centauri. Let’s also shrink that star down to a baseball for our scale model. The question is: where would the Alpha Cen baseball be located?

It would not be in the infield, or the outfield, or anywhere in the ballpark. It would not be in the city of Baltimore or even in the state of Maryland. For a correct scale model, the Alpha Cen baseball would be about 1,300 miles and many states away — in Houston, Texas.

One baseball in Camden Yards and one baseball in the Astrodome — that’s the relative size and separation of the stars in our part of the galaxy. You can see that there is a lot of space between Baltimore and Houston for other baseballs to pass through.

Hence when galaxies collide, the stars stream past each other at vast separations. The orbit of our Sun within the combined galaxy may change greatly, but the orbits of the planets around the Sun will not be affected.

One can rest easy knowing that our solar system will survive the great collision between the Milky Way and Andromeda. However, that doesn’t mean that the billion-year future of Earth is all rosy. There are other factors that will greatly alter our planet. I’ll discuss those in my next posting.

Sharing Astronomy With All

June 14, 2012 by Mangala Sharma

Saturn's ringsThere’s so much about our cosmos that engages our sense of wonder and awe. Through astronomy, humans hunt for answers to some of the most fundamental questions that tease our curiosity and intelligence.

Practically everyone around the world participates, to varying degrees, in astronomy. We may be occasional observers, led by our natural fascination with the sky, aware of how the Moon waxes and wanes, or we may gasp over the momentary splendor of a “shooting star.” We may follow astronomy news daily or pore over gorgeous astronomical images on websites such as HubbleSite. Some of us contribute our computer’s idle CPU cycles to cool projects like SETI@Home, searching for extraterrestrial intelligent life by analyzing cosmic radio signals. Hundreds of thousands of people are amateur astronomers or citizen scientists, observing the skies themselves or delving into the thicket of archival astronomy data. And a handful of us are professional astronomers, a niche market of only about 15,000 worldwide.

I love the fact that, at any point in time, somewhere on (or just above!) the Earth, humans are accessing astronomical experiences and discoveries. Access to such data or discoveries doesn’t happen by magic, though. It takes the creative and dedicated efforts of a large community of professionals or volunteers. Scientists and engineers working on astronomical archives and data centers such as the Space Telescope Science Institute’s (STScI) Mikulski Archive for Space Telescopes (MAST) make their collections available to not only professional astronomers, but also citizen scientists and anyone with an Internet connection anywhere in the world. There are thousands of college professors, teachers and education/outreach professionals preparing future generations of scientists and a science-literate public all over the globe. Amateur astronomers are wonderful ambassadors, connecting people to the wide cosmos through a telescope’s eyepiece.

Personally, I have benefited from every such effort, and strive to return the favor. Among my favorite memories from my days as a student in India is participating in, and then helping run, a telescope-making workshop for high school students: in barely 10 days, we made concave mirrors by grinding and polishing 6- or 8-inch glass blanks by hand, and used plastic tubes and store-bought eyepieces to rig decent reflecting telescopes. You can imagine our pleasure at seeing Saturn and distant nebulae through a ‘scope we’d built ourselves – everything looked gorgeous, even in poor seeing conditions or through patchy clouds!

For some years now, with other professional and amateur astronomers, I’ve taken small solar telescopes (with safe solar filters) to neighborhood farmer’s markets. It’s delightful to hear people exclaim as they see sunspots or solar flares, and experience the complexity and beauty of our own star.

Currently, I work at STScI’s Office of Public Outreach, being paid to do what I love – sharing astronomy. The tradition of sharing astronomy with all easily goes back to the Renaissance. Galileo, who first turned a spyglass skyward, took his handmade telescopes to the streets and gave the common man a chance to discover the craters of the Moon and the phases of Venus.  In 2009, we celebrated the 400th anniversary of Galileo’s pioneering work as the “International Year of Astronomy” (IYA). The UN-declared IYA encouraged people across the globe to get close and personal with astronomy, discover the universe for themselves, and gain a deeper appreciation of astronomy’s place in human culture. And millions of people all over the world did. Perhaps some inspired students will go on to become scientists themselves.

Which brings us to the question: why do we work to make astronomy available to all? For one thing, it’s the taxpayers that provide the majority of funding for professional astronomy. It makes sense to share with them the scientific returns on their investment, and garner their continued support for science. Science is more and more relevant to everyday life, and it’s in our best interests to ensure that people bring well-informed perspectives to policy decisions that affect scientific pursuits. Just as importantly, it’s a culture and viewpoint thing. “One sky connects us all!” goes the tag line for the American Astronomical Society. Can’t argue with that.

Dragon’s Lair

June 5, 2012 by Alberto Conti
Maneuvering Dragon to the docking port of the International Space Station. CREDIT: Andre Kuipers/ESA/NASA

Maneuvering Dragon to the docking port of the International Space Station. CREDIT: Andre Kuipers/ESA/NASA

On the tail of my last post about Planetary Resources’ goal of mining asteroids, last week I was reminded on three separate occasions of the excitement I often feel when thinking (and dreaming) of our place in the universe. It’s a remarkable time.

First, on May 20 (May 21 in in the Eastern Hemisphere), a spectacular annular solar eclipse took place. Such an eclipse occurs when the Moon passes between Earth and the Sun, partially obscuring the image of the Sun for lucky observers here on Earth. The key word here is “partially.” In these types of eclipses, the Moon is unable to completely cover the surface of the Sun, leaving an annulus known as the Ring of Fire. Fortunately, even if I was not one of the lucky ones to view the event in person (the eclipse was not visible from the East Coast of the United States), an abundance of live feeds on the Internet allowed me to truly feel part of the action.

Then, on May 25, the board of the Square Kilometer Array (SKA) Organization convened in Amsterdam to announce their final decision on the site that will host the SKA radio telescope. This decision was important for astronomy in that SKA will be the world’s largest and most sensitive radio telescope ever built. The decision was an anticlimactic tie, in that SKA antennas will be hosted both in South Africa and Australia, but this was somehow expected. SKA is big science with the potential of big discoveries, and many wanted to be part of it.

I will come back to SKA in an upcoming post, given that in this case big science truly means big data as well.

Finally, a Dragon ran from Earth but was captured by the International Space Station (ISS). Just when many of us looked with apprehension at a future without reusable vehicles like the Space Shuttle, and thought that exploration had effectively been put on hold, NASA sanctioned a commercial company to deliver “groceries and supplies” to the ISS, thereby opening the door for a viable commercialization of space. The successful mission of the unmanned cargo capsule, named Dragon, could potentially be a game changer, particularly if companies like SpaceX will initially take the role that FedEx on Earth has assumed for our personal packages. However, in light of Planetary Resources’ announcement, I believe many companies are now on a trajectory that will put them at the forefront of space exploration: delivering packages is just a required stepping-stone. SpaceX needs to learn how to dock before it can plan on orbiting another planetary body.

Most of the success of companies like SpaceX is due to the remarkable ingenuity and entrepreneurship of people who simply never stopped dreaming about space. A few individuals, after having made a fortune in business, are now turning to their “hobby.” Luckily for all of us, their hobby is the exploration of space. This is indeed the case for Elon Musk, CEO and Chief Designer of SpaceX. He co-designed one of the first viable electric cars of the modern era, the Tesla Roadster, he co-founded what is now the world’s largest Internet payment system, PayPal, and he built SpaceX, the first commercial space company able to send its own capsule to the International Space Station.

SpaceX has effectively opened a new era for private spaceflight after the end of the 30-year U.S. shuttle program. I think this maiden flight and docking to the ISS will someday be recognized as a historic event, even if only for the potential to inspire others to reach further in our planetary neighborhood.

Elon Musk is only 40 years old, and if the past is any indication about his capabilities of turning ideas into products (SpaceX was founded just 10 years ago), I expect to see a big push in the coming years for a much bigger mission: Mars, within his lifetime.

It’s starting to feel like the early 60s all over again: a time where anything in space seemed possible!

Crash of the Titans

May 31, 2012 by Frank Summers
ILLUSTRATION CREDIT: NASA, ESA, Z. Levay and R. van der Marel (STScI), and A. Mellinger

ILLUSTRATION CREDIT: NASA, ESA, Z. Levay and R. van der Marel (STScI), and A. Mellinger

Imagine what goes through the mind of a baseball batter as he stares down a speeding pitch. The baseball is hurtling toward him, but difference between a strike and a ball depends on precisely gauging the amount of sideways motion. He’ll want to swing for the fences if it’s out over the plate, or jump back out the box if it’s headed for his ear.

Astronomers have been pondering a similar situation for about a hundred years. We can easily measure whether the neighboring Andromeda galaxy is moving toward or away from us (we call this “radial” motion). The result, known to Edwin Hubble in the 1920s, is that Andromeda is approaching our Milky Way galaxy at the tremendous speed of more than 250,000 miles per hour.

However, it is extremely difficult to measure the sideways (or “tangential”) motion of a galaxy. We have been left wondering: what is Andromeda’s full trajectory? Will the two galaxies simply pass by each other like cars on opposite sides of an interstate highway, or will there be a colossal pileup involving hundreds of billions stars in each galaxy?

It has taken Hubble’s namesake telescope, with its exquisite resolution, and some innovative imaging and computational measurement techniques to finally answer this question. By measuring minute shifts in the stars of Andromeda over the course of about a decade of observations, we now know that Andromeda has very little sideways motion. It is heading straight for the Milky Way, and, unlike the baseball batter, our galaxy can’t get out of the way.

VISUALIZATION: NASA, ESA, and F. Summers (STScI)
SIMULATION: NASA, ESA, G. Besla (Columbia University), and R. van der Marel (STScI)

The two galaxies have been destined by gravity to crash together in about four billion years. Their thin and beautiful spiral disks will become warped, stretched, and distorted beyond recognition. The centers of the galaxies will smash through one another not just once, but several times as the galaxies merge. Eventually, about six billion years from now, the two spirals will become one elliptical galaxy, mixed together for all eternity.

Our visualization of this galactic gravitational dance is the first scientific look into the far-flung future of our galaxy. Our news release features artistic visions of what the view might be from within the Milky Way during the collision. The stars and the band of the Milky Way across the night sky seem static and constant on human time scales. But taking an astronomer’s perspective, and looking forward billions of years, they have quite a dynamic future ahead of them.

Examining Venus in a Lunar Mirror

May 25, 2012 by Frank Summers
blog_2012_05_25

Hubble can't look at the Sun directly, so it will observe the Venus transit with sunlight reflected off the Moon.

On June 5, 2012, the last Transit of Venus will happen in your lifetime. Unless, of course, you plan on living until December 2117 to catch the next one. Because it is the “last chance of a lifetime,” folks are clamoring about when and how to observe it. But I’ve found that many people have even more basic questions like “What exactly is happening?” “Why should I care?” and “Won’t Hubble get the pretty pictures for us?”

First off, the event is that the planet Venus will pass directly between Earth and the Sun. For several hours, Venus will appear as a dark dot moving across the Sun’s brilliant face. The precise alignment required for such a transit happens very rarely: pairs of Venus transits are separated by eight years, with 105.5- or 121.5-year separations between pairs. The first of this current pair occurred in 2004. The 2012 transit of Venus is only the eighth since the telescope was invented in 1609.

Historically, Venus transits were very important in measuring the precise distance to the Sun. A single measurement of a transit provides the relative sizes and distances to Venus and the Sun. Multiple measurements from multiple places on Earth enable astronomers to triangulate the true distance to the Sun. In the 1700s and 1800s, no other astronomical observation could provide this measurement, and grand expeditions were funded to observe Venus transits.

Today, we have radar measurements of the distance to Venus, so transits are not the unique opportunity they once were. For Hubble, however, the 2012 transit of Venus will be a unique opportunity of a totally different dimension.

Exciting discoveries can be made by studying an extrasolar planet that transits in front of its star. Some of the star’s light passes through the planet’s atmosphere, and we can determine the composition of that atmosphere. The same argument applies to the transit of Venus. However, since we know the composition of Venus’ atmosphere, observing its transit can provide an invaluable calibration and substantiation of the techniques used on extrasolar planets.

But, Hubble never looks at the Sun. Our star’s dazzling light would irreparably damage the telescope’s optics. Instead, Hubble will use the Moon as a giant mirror, studying its reflected sunlight to glean information about the Venus transit. It is a difficult observation, but one that mimics some of the complexity of observing extrasolar planets.

Who would have thought that the path to searching for habitable planets in the universe would involve examining Venus in a lunar mirror?

A Virtual Universe Awaits Future Astronomers

May 18, 2012 by Ray Villard
HubbleSite: NSF Grant to Fund "National Virtual Observatory"

Data from ground-based and orbiting telescopes will be united in the National Virtual Observatory.

Being an astronomer in the year 2030 will be notably different than it is today. Yes, scientists will still be pondering, among other mysteries, the evolving universe, life on other worlds, and the nature of dark energy.

But how they explore the universe is already changing. This is partly driven by the fact that we are riding an exponential curve of increasing telescope size and detector sensitivity, but much more importantly, huge amounts of observational data are being harvested and archived faster than astronomers can analyze.

In addition, amateur astronomers are becoming more heavily involved in this analysis than in recent decades because of the “democratization” of space via huge, publicly accessible astronomical databases.

The consequences are that we are on the cusp of a knowledge explosion in astronomy, where discoveries expand at an unprecedented rate across the globe. Our knowledge of the universe is becoming, well, inflationary.

One prime example is the Barbara A. Mikulski Archive for Space Telescopes (MAST), housed at the Space Telescope Science Institute. This remarkably vast database contains astronomical observations from 15 NASA space astronomy missions, including the Hubble Space Telescope and the James Webb Space Telescope.

MAST presently contains approximately 200 terabytes of data that are used and reused many times by astronomers. New data are constantly flowing into the archive, but even more data is flowing out. Today, more than half of published scientific papers containing Hubble data used archival observations. This number has increased steadily over the past five years.

Facilities like MAST will lead to a new breed of “office-chair astronomer” who explores a “virtual universe” of vast, interconnected online databases. This is called the Virtual Observatory, and it is now in its developmental period.

What’s more, “citizen scientists” — those without formal degrees in astronomy — will have open and free access to the same data mines to make their own discoveries.

In 2030, a typical day for an astronomer on a university campus will have her start her work by looking at a list of science papers that have been intelligently selected by a software tool that surfed the Internet overnight. She clicks on an object in an online science paper and the Virtual Observatory database delivers views in X-ray, visible light, and infrared and radio observations. She queries the archive to perform an intelligent search, pulling up information relevant to the questions she’s asking about the object.

She never goes to a mountain top observatory to do follow-up observations of the object. Instead this is all carried out autonomously, following acceptance of her observing proposal. Automatically processed and calibrated observations are quickly delivered for high-level analysis after the observation. This online pipeline processing of data is a procedure pioneered on the Hubble Space Telescope mission, which has amassed 60 terabytes of observations to date.

Her observation goes into the Virtual Observatory archive after a brief proprietary period. Her unrefereed science results are soon published online. Peers and lay readers comment on the results, which are disseminated through social media. Her formally accepted paper is next published freely in an open-access online journal. Students in impoverished third-world universities have the same access to her results as a Harvard astrophysicist does.

Armchair astronomers will focus on complex and innovative queries of the Virtual Observatory to automatically search and extract precise sets of observations made by a variety of telescopes. Researchers will make new discoveries purely by being able to cleverly combine data from different wavelengths, spectra, and transient changes in space.

Many thousands more inquiring minds will be able to explore the databases, too. A prototype for this is the Galaxy Zoo project, where members of the public classify galaxies found in astronomical data. In 2007, Dutch schoolteacher Hanny van Arkel was participating in the Galaxy Zoo project when she found a huge, ghostly, glowing blob of gas, an oddity illuminated by a beam of light from a black hole in the core of a nearby galaxy.

We are just beginning to ride the wave of incredible new insights into our universe.