What is the Virtual Astronomical Observatory?
The Virtual Observatory (VO) is an international effort to bring a
large-scale electronic integration of astronomy data, tools, and
services to the global community. The Virtual Astronomical Observatory
(VAO) is the U.S. NSF- and NASA-funded VO effort that seeks to put
efficient astronomical tools in the hands of U.S. astronomers,
students, educators, and public outreach leaders. These tools will
make use of data collected by the most powerful telescopes in the
world.
What you find find on this page:
Winds of Change
Astronomy has historically been a fragmented science. Astronomers
would typically work alone or in small research groups to conduct
observations of small, carefully selected samples (often with a priori
prejudices) of objects in a limited part of the electromagnetic
spectrum. Results were not always shared with the public, and if they
were, they were shared passively without an active role from
interested students, teachers, amateur astronomers, and the general
public. In the past decade, a paradigm shift has begun that will
forever change how astronomical research is conducted and shared with
the public. Astronomers are now increasingly working in large
collaborations using survey telescopes or multiple telescopes covering
a wide range of the electromagnetic spectrum. Astronomers today have
more data at their disposal than at any other time in history. This
paradigm shift is occurring because of the following four main drivers
of change.
Technical assistant Bill Binkert is seen here checking cables on the Mayall
4-meter telescope at Kitt Peak. Credit: John Glaspey/NOAO/AURA/NSF
Telescopes that are more powerful due to
enhanced design and fabrication
Larger and more sophisticated telescopes are able to take more high
resolution images and spectra of the Universe. Over the past couple
of decades, a new type of telescope became popular, the survey
telescope. These telescopes were not developed to target specific
objects, but were instead developed to survey much of the sky.
Astronomers could then look for specific objects or do a census of
objects over much of the sky. Astronomy was now going to get
statistically large samples of objects in the Universe with which to
study. Current surveys include the Sloan Digital Sky Survey (SDSS),
the Two Micron All Sky Survey (2MASS), the Massive Compact Halo
Objects (MACHO), and the ROSAT All Sky Survey (RASS). The future
Large Synoptic Survey Telescope (LSST — scheduled to begin
science operations later this decade) will produce a wealth of data by
repeatedly scanning the sky over a 10 year period. The LSST will not
just produce a map of the Universe, but discover all sorts of objects
that change between observations giving us insight into whole new
classes of variable objects.
Mt. Hopkins 1.3-Meter Two Micron All Sky Survey (2MASS) Telescope. Photo by Rae Stiening
Along with the advent of survey telescopes, astronomers are finally
able to probe larger swaths of the electromagnetic spectrum with
fleets of ground- and space-based telescopes. We now have telescopes
observing the Universe from the high energy gamma rays to visible
light and down to the low energy radio waves. Many of these
telescopes are launched into space as a necessity; many types of light
of the electromagnetic spectrum cannot pass through Earth's
atmosphere, such as gamma-rays, x-rays, ultraviolet, and infrared
light.
Hubble/GALEX/Spitzer Composite Image of M81
Credit: Hubble data: NASA,
ESA, and A.
Zezas (Harvard-Smithsonian Center for Astrophysics); GALEX data:
NASA, JPL-Caltech, GALEX
Team, J. Huchra et al. (Harvard-Smithsonian Center for
Astrophysics); Spitzer data: NASA/JPL/Caltech/Harvard-Smithsonian
Center for Astrophysics
From these advances in telescope design, the general public now has
access to multiwavelength images. Student projects are being
developed to teach the power of using the full electromagnetic
spectrum to study the universe. The sure amount of data from surveys
and powerful telescopes are allowing anyone interested become citizen
scientists and are helping classify objects in the universe, do
population studies of objects in the universe, and even discover all
new objects in universe.
Detectors that are larger, more sensitive to light, and have
higher resolution
While the mirrors or optics in telescopes act as giant light
buckets collecting as much light as possible, the detectors capture
that light for us to study. In the earliest days of telescopic
astronomy, astronomers could only use their eyes as detectors. If
they wanted to show another person their discoveries, they had to draw
what they saw by hand. This was obviously a very imprecise way to
practice astronomy, and the eyes are only capable of detecting visible
light. By the late 19th century, photographic plates were used to
capture the light gathered by telescopes. This was far superior to
using eyes, since photographic plates could lay exposed to incoming
light for hours at a time, thus, building up images of fainter
objects. Photographic plates did have several disadvantages. They
were heavy, difficult to process, and not as accurate as modern day
detectors.
All of the new advances in telescope design are taking advantage of
more advanced detectors that can accurately count individual photons
of light. Modern day detectors are called charge-coupled devices
(CCDs) and are used in everything from common digital cameras to the
most state-of-the-art telescope. Each CCD is made up of individual
light-sensing pixels. The more individual pixels packed onto a given
size of CCD, the better the resolution of the resulting image. Higher
resolution images are more clear and detailed. Lower resolution
images appear increasingly blurred out. Currently, the typical
cameras purchased by a consumer have detectors with less than 20
million pixels. Astronomical-grade cameras use various types of
detectors that can produce sharper images and capture larger swaths of
the electromagnetic spectrum. As a comparison, the SDSS telescope has
a 120 million pixel detector. The future LSST will have a 3,200
million pixel detector.
The higher resolution images produced by state-of-the-art
astronomical-grade detectors are leading to a huge increase in data.
Each individual pixel is actually data that must be recorded for
analysis. These are producing incredibly detailed images in multiple
wavelengths for the general public to admire. Amateur astronomers can
purchase their own detectors for use on their backyard telescopes to
create images that sometimes rival several ground-based research-level
telescopes. Students also now have access to higher quality
astronomical data.
Exponential growth of computing capability
The current technological explosion of telescope and detector
capabilities is producing a huge amount of data. With this, we
require more powerful computers to store and analyze the data. The
SDSS, alone, is producing terabytes of data. The future LSST will
produce more than 50 petabytes of data. One petabyte is equivalent to
the amount of data obtained by all of CNN's news footage over five
years. Thankfully, computing capability has greatly increased,
following the famous Moore's Law. Moore's Law states that
computing power doubles every 18 months. This increase in computing
power is critical to keep up with the increasing flow of data by
detectors on telescopes. Incidentally, the rate of increase of the
numbers of pixels on a CCD detector, or the quantity of data collected
by that detector, also follows Moore's Law.
"Moore's Law states that
computing power doubles every 18 months." Display from: Towards the Virtual Observatory
The growth of computer usage in homes and schools is providing the
necessary infrastructure for the general public and students to study
and use the astronomical data. Along with the advent of high-speed
internet, as described below, the public now has the means to help
carry out astronomical studies where large numbers of computers and/or
users are required.
Expanding coverage and capacity of communication networks
Due to the increased computer power, along with the development of
high speed internet and broad internet coverage, astronomy is primed
to take advantage of the wealth of astronomical data. In 2002, it
would take about 20 days to transfer one terabyte of data over the
internet. In 2012, using an internet connection of 10 megabytes per
second, it would take about 10 days to transfer one terabyte of data.
With faster connection speeds, this can be reduced to a few days. The
speed of internet connections will continue to increase in the years
ahead. With the spread of internet, users can have access to the
large data archives spread around the world nearly instantaneously.
Users will also have access to internet cloud storage and online tools
that help them analyze the data. This will create less reliance on
having the absolute best computer in your home, office, or school.
These infrastructure gains will help pave the way to the discovery of
new phenomenon, previously undiscovered patterns in data, simultaneous
access to astronomical data archives with access to images and spectra
taken by the world's most powerful ground- and space-based
telescopes, broad access by anyone with internet access, and new
learning and analysis tools.
There are several examples of how any combination of the above four
key changes can influence astronomical discoveries. Historical
examples include the discovery of quasars when viewed using multiple
portions of the electromagnetic spectrum (radio and visible light in
this case). Extremely luminous objects in the universe were
discovered when viewing in the infrared. These bright objects were
hidden behind thick clouds of dust that block visible light but glow
brightly from the heated dust emitting infrared light. It is believed
that nearly half of all star forming regions may be escaping detection
when using only visible light for their detection. The properties of
cosmic gamma-ray bursts, extremely powerful explosions in the universe
thought to come from exploding stars and colliding stellar remnants,
are being understood now due to observations from multiple portions of
the electromagnetic spectrum, including x-rays, visible light, and
radio waves. What else is out there? What more can we learn? We now
have the capabilities to answer these questions.
Stellar Jet in the Carina Nebula
Hubble Space Telescope, WFC3/UVIS/IR
This change is happening, but how do we take advantage of it? How do
we make sure the public also gains the benefits of this "new
astronomy." The answer is to create a virtual observatory (VO).
Virtual in that the user obtains and interacts with the data via
web-based tools, and an observatory in the traditional astronomical
sense in that it will be a general purpose instrument as opposed to an
instrument designed for one specific purpose or goal.
Laying the Foundation of a National Virtual Observatory
The idea to create a National Virtual Observatory (NVO) was
presented in the National Research Council's decadal review entitled,
"Astronomy and Astrophysics in the New Millennium," released in 1999
and published in 2001. The decadal review sets the national priority
for astrophysics for the following decade. In the decadal review, the
NVO was rated the highest priority for small (less than 100 million
dollars) projects. From the decadal review:
The NVO will provide a "virtual sky" based on the enormous data
sets being created now and the even larger ones proposed for the
future. It will enable a new mode of research for professional
astronomers and will provide to the public an unparalleled opportunity
for education and discovery.
In response to the recommendation given in the decadal review, NASA
and the National Science Foundation (NSF) established the Science
Definition Team (SDT). The SDT created a report in April 2002
entitled, "Towards the National Virtual Observatory." The goal of the
SDT was to lay out a plan for implementing the NVO with real proposed
science projects as the motivation and direction.
All of the major NASA missions, along with other national and
international missions, store their images and spectra in data
archives. There is a wealth of information from those images that has
not been explored. That data belongs to the scientists who first
proposed the experiment, typically, for about a year. After this
period, the data become available to anybody, including the general
public. Each archive traditionally sorted and accessed data using
their own standards. The archives did not communicate with each
other. In the era of multiwavelength, time-domain, and survey
astronomy, this is a roadblock to doing good science. The NVO was
tasked with overcoming these barriers by creating common standards by
which the archives would catalog their data and communicate with
users. In so doing, the NVO would be a one-stop place where a person
could easily access data from any or all of the archives instead of
searching separately.
In many ways, the NVO was equivalent to today's airline or hotel
reservation systems like Travelocity or Expedia. A traveler can use
these services to compare prices, schedules, and amenities among
airlines or hotels. The user can choose hotel or airline that suits
them the best. The NVO, likewise, was envisioned to be a central
place where astronomers, students, educators, or any other interested
user could find images or spectra of any type of object from any
archive.
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| The NVO was equivalent to today's airline or hotel
reservation systems like Travelocity or Expedia. |
To successfully create this centralized hub of data access and
analysis, the SDT envisioned a three phase process to implementing the
NVO.
- Phase I: conceptual design of the NVO, expanded definition of the
science that will drive the development of the NVO, implied technical
capabilities, management structure and costing issues.
- Phase II: definition of the NVO operational/management structure, a
detailed implementation plan, increased capabilities implemented
within existing data centers/archives/surveys/observatories, and
increased community input and involvement.
- Phase III: implementation of the full-fledged NVO structure with
international connections, the start of NVO-based science programs,
and the start of routine operations.
Even in this earliest phase of a national virtual observatory plans
were being formulated on how to capitalize on the unique capabilities
of the NVO to teach science, technology, engineering, and math (STEM)
subjects. From "Towards the National Virtual Observatory:"
The NVO effort also provides a unique opportunity to enhance
technology literacy in a broad sense. The NVO will inform, excite,
and educate the public about space science and astronomy, and serve as
a catalyst for scientific and technological literacy in the United
States.
Success of the NVO
The NVO was an ambitious project that was clearly defined by the
SDT. In the report by the SDT, it was noted that the foundational and
infrastructure problems had to be solved before any operational VO
could be put into place. By the end of the NVO funding in 2010, much
of these issues had been solved. There was a management, operations,
and organizational structure in place, which is critical for a
geographically distributed project like the VO (member institutions
are from all over the U.S. and the world). A new set of VO-standards
were implemented into most of the large astronomy data archives for
simple retrieval of information. These standards were created and
adopted across the world with the help of the newly-formed
International Virtual Observatory Alliance (IVOA), of which presently
includes more than 20 nations with individual VO programs. These
include the United States, France, Germany, Canada, China, India,
Italy, United Kingdom, Japan, Brazil, Australia, and more.
The NVO and international VO programs were not the only groups
building and supporting VO infrastructure and tools during the decade.
Microsoft Research was one such leading organization. In 2001, Jim
Gray of the Microsoft Research Center and Alexander Szalay, who was
one of the principal investigators of the NVO, wrote up a viewpoint
article for Science entitled, "The World-Wide Telescope." In this
article, the justifications for embarking on a national virtual
observatory were given, including strong educational motivations.
From the article, Gray and Szalay made a point that the VO can help
educate the students and the general public in areas such as
astronomy, physics, chemistry, computational science, and mathematics.
The efforts of Microsoft Research's VO efforts have led to the
development of the WorldWide Telescope (WWT), a beautiful
visualization tool that makes use of the VO infrastructure to provide
real astronomical images. Jim Gray was lost at sea in 2007 during a
solo boating trip. Microsoft has dedicated WWT to Jim Gray.
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Jim Gray was lost at sea in 2007 during a
solo boating trip. Microsoft has dedicated WWT to Jim Gray.
Photo of Jim Gray from
Microsoft press release about Gray receiving the Turing Award in 1999. |
With the ground-work laid out by the NVO and its national and
international partners, the time to use the VO is here. Some tools
have been developed for the VO and many more are in the pipeline for
use by both professional astronomers AND the general public. These
tools have various attributes that allow the user to acquire data,
analyze data, and learn about the Universe using beautiful
visualizations. With the NVO era now over, a new organization has
been funded in its place with the explicit goal of creating useful
tools for users to take advantage of the groundwork laid by the NVO.
To carry on with the NVO's goals, we introduce to you the Virtual
Astronomical Observatory.
The Establishment of the Virtual Astronomical Observatory
The Virtual Astronomical Observatory (VAO) is the U.S. NSF- and
NASA-funded VO effort that seeks to put efficient astronomical tools
in the hands of U.S. astronomers, students, educators, and public
outreach leaders. From the Mission Statement in the VAO Project
Execution Plan (2010),
"The VAO, building on the success of prior infrastructure
developments, is now poised to realize the benefits long-promised to
the astronomical research community, and more generally, educators and
the general public."
The VAO has a current funding and development path for five years.
Many tools are being developed by the VAO, and its national and
international VO collaborators, to make accessing and analyzing
astronomical data simple and intuitive for professional astronomers
and the general public. Some of these tools include:
- Data Discovery Tool — Retrieve
astronomical data about a given position or object in the sky.
- Aladin — Find and overlay images from different parts of the
electromagnetic spectrum.
- Cross-match tool — Find all objects of a given type or at a
given location between all archives.
- IRIS — Find, plot, and fit spectral energy distributions
(SEDs). SEDs are the brightness profiles of objects at many
wavelengths.
- VOPlot — Plot results from VO queries.
- Skyalert — Monitor real-time alerts of transient events.
These include variable stars and supernovae.
- Time series tools — Obtain an object from multiple
archives/observations to analyze how it varies its light output with
time.
- Montage — Make large mosaic images of survey data.
- Microsoft's WorldWide Telescope — Visualization software
that allows the user to explore the Universe and look at astronomical
images taken by many of the world's telescopes. WWT has the unique
feature of allowing the user to create special tours around objects
that can be shown as video to others.
- Google Sky — Visualization software that allows the user to
explore the Universe and look at astronomical images taken by the many
of the world's telescopes.
Most of these tools can be found by going to the VAO science site,
here. WWT can be found here, and Google Sky can be found here. To
help develop and refine the tools, the VAO is working with science
teams and EPO professionals. Some of the current science teams run
the gamut from those that study star formation and evolution to those
that study galaxy formation and evolution.
The VAO has firmly established an EPO program to deliver the
capabilities of the VO to students, educators, amateur astronomers,
citizen scientists, and the general public. From a founding document
of the VAO entitled, "A Vision for the US Virtual Astronomical
Observatory," (2010):
"The VAO will be an invaluable resource in any effort to address public
science literacy through the use of astronomy; its rapid access to
astronomy data, archives, images and literature through a single point
of contact will facilitate the creation and maintenance of programs
designed to increase public awareness of science."
The plans for the VAO EPO program are given in a bit more detail
below. See the "About Us" section to learn more about the VAO EPO
team.
The VAO: New Resource in Education and Public Outreach
The VAO EPO program is led by the Space Telescope Science Institute
(STScI) in collaboration with the NASA Goddard High Energy
Astrophysics Science Archive Research Center (HEASARC) EPO program and
the Johns Hopkins University (JHU). VAO EPO efforts seek to bring
technology, real-world astronomical data, and the story of the
development and infrastructure of the VAO to the general public and
education community. Our EPO efforts will be structured to provide
uniform access to VAO information, enabling educational and research
opportunities across multiple portions of the electromagnetic spectrum
and time-series data sets. Given the nature of the VAO project, it is
well suited to exploring science, technology, engineering, and math
based subjects since the VAO project relies considerably on using
computers and technology to give us the capabilities to learn
scientific concepts (of which math is heavily utilized). We are
providing a resource to the general public, educators, and students
that were not there before. For the first time ever, anybody can have
equal and open access to real astronomical data, so long as they have
an internet connection.
The VAO EPO team is working with the VAO community, the larger
international VO community, and outside organizations to utilize tools
appropriate for the high school and community college students.
Formal Education:
The VAO EPO effort will provide the high school and community college
community with a way to understand STEM concepts via curriculum
support tools that use real astronomical data and are aligned with
national standards and benchmarks. The VAO EPO team has the benefit
of professional astronomers working in concert with professional
educators. It is not enough to create materials and hope they are
used and used properly. A proper formal education program must ensure
that students are truly benefitting from the materials and proper
instruction. For this reason, the VAO formal education program's
implementation strategy includes needs assessments to be sure we are
meeting the needs of educators, alignment with national benchmarks and
standards, professional development opportunities for educators so
that they understand how to properly use the materials, and impact
studies to be sure that our materials are effective and are being
taught properly.
The VAO EPO program has the goal of meeting the needs of high school
and community college educators and students. Our formal education
program aims to utilize many VO tools, including Microsoft's WWT,
Aladin, Data Discovery Tool, and others.
United States Virtual Observatory Timeline
2000: Decadal Review names the National Virtual Observatory (NVO) as
the top small initiatives project.
2001 July - March 2002: Science Definition Team (SDT) responding to
Decadal Review
2001, April 23: ITR/IM: Building the Framework for the National
Virtual Observatory submitted, this is a copy of the original proposal
to NSF's Information Technology Research (ITR) Program
2002, April: Toward the National Virtual Observatory, a report
prepared by the National Virtual Observatory Science Definition Team
2002, June: International Virtual Observatory Alliance (IVOA) founded
2002, July 12: White paper published
2004: First NVO Summer School, The Aspen Meadows Resort, Aspen,
Colorado
2005, September 6-15: Second NVO Summer School, The Aspen Meadows
Resort, Aspen, Colorado
2006, September 6-14: NVO Summer School, Aspen, The Aspen Meadows
Resort, Aspen, Colorado
2008, September 3-1: NVO Summer School, The Lodge at Santa Fe, Santa
Fe, New Mexico
2009, April 3: The Role of the Virtual Observatory in the Next Decade
2010, October: A Vision of the US Virtual Astronomical Observatory
2010, May 15: The NSF and NASA announce a cooperative agreement to
create a new research facility for astronomy: the Virtual Astronomical
Observatory
2011, November 30: VO Day in Boston, MA. Showcasing VAO tools to the
astronomical community.
2011, December 7: VO Day in Pasadena, CA. Showcasing VAO tools to the
astronomical community.
2012, January 8: AAS Workshop: Science Tools for
Data—Intensive Astronomy. Professional astronomer component and
educator component, Austin, TX.
VAO Senior Personnel
Robert Hanisch, Director
Joseph Lazio, Project Scientist
Alex Szalay, Technology Advisor
Bruce Berriman, Program Manager
Marie Huffman, Business Manager
Robert Hanisch is a Senior Scientist at the Space Telescope Science Institute in Baltimore, MD.
Dave De Young (NOAO) was NVO and VAO Project Scientist before Lazio.
Joseph Lazio is the Principal Research Scientist at the Jet Propulsion Laboratory at California
Institute of Technology in Pasadena, California.
Alex Szalay is the Alumni Centennial Professor in the Department of Physics and Astronomy at
John Hopkins University.
Bruce Berriman is an astronomer and computer scientist at the Infrared Processing and Analysis
Center, California Institute of Technology.
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