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Every
week, the Large-aperture Synoptic Survey Telescope (LSST), whose
6.5-meter mirror has been shaped to provide a much wider field of
vision than that of other telescopes, will survey the entire sky,
producing an almost real-time movie of the night sky.
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Image
showing the gravitational "fish-eye lens" effect.
The dark matter in the massive cluster of yellowish galaxies
curves space-time to such a degree that the light from a more
distant blue galaxy behind the cluster is focused toward Earth
and appears as the distorted blue arcs around the edge of
the "lens."
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These
surveys will be produced in digitized format and distributed immediately
to astronomers and the public over the Web. They will yield a wealth
of data that will open our eyes in new ways to cosmic objects that
vary in brightness on time scales of days, weeks, months, or years,
and range in distance all the way from the outer reaches of the
visible universe down to the dangerously close. LSST will discover
approximately 100,000 supernovas each year, located in galaxies
many millions or even billions of light-years from the Milky Way,
some of which can be studied in detail with the GSMT. Another benefit
of LSST's deep-space survey will accrue from its ability to find
places in the night sky where a massive object happens to lie almost
directly between Earth and a still more distant object. Under these
circumstances, the massive object magnifies the light from the more
distant object by bending nearby space. LSST's measurements of these
magnification effects will allow us to map the distribution of dark
matter in space. This map will test, on the largest attainable distance
scales, evidence of the acceleration of the expansion of the universe,
theorized to be due to the presence of so-called dark energy. Much
closer to Earth, LSST will find 90 percent of all the near-Earth
objects-asteroids moving on orbits that pass close to our own-with
diameters that exceed 300 meters. Each of these asteroids represents
a potential threat worth identifying and assessing,since a collision
of such an asteroid with our planet could produce localized, if
not planet-wide, disaster.
LSST
will also study comets and their close cousins,the members of the
Kuiper Belt. Most of the comets that we see probably originate in
the Kuiper Belt, a collection of minor planets orbiting beyond Neptune.
The Kuiper Belt is the remnant of the protoplanetary disk of material
that once orbited the Sun and produced the planets and their large
satellites nearly 5 billion years ago. These remnants incorporate
the nearly pristine record of the composition and dynamics of the
Sun's protoplanetary disk. Astronomers have now discovered more
than 500 separate objects in the Kuiper Belt,most with diameters
between 100 and 800 kilometers. Deeper surveys made with the LSST
should reveal many more of these objects, which are believed to
number nearly 100,000, with diameters larger than 100 kilometers.
Astronomers suspect that among them may be perhaps as many as 10
objects as large as Pluto (2,000 kilometers across), but several
times farther from the Sun.
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Optical
image of the asteroid Ida (more than 50 kilometers long) and
its moon Dactyl taken by the passing Galileo spacecraft.
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LSST
should generate the largest nonproprietary database and data- mining
system in the world, adding the dimension of time to the three spatial
dimensions in our knowledge of the cosmos. The classification, analysis,
and distribution of an anticipated trillion bits of data collected
each day represent an enormous challenge.
Visit
the Official LSST Site
The
National Virtual Observatory (NVO) Will Provide User-Friendly Access
To The Nation's Large Astronomica Databases
The
National Virtual Observatory (NVO), the highest priority among the
recommended small initiatives, will link all major space-and ground-based
astronomical data banks into a virtual Web-based system. The NVO
is intended for users from grade-school children to professional
astronomers, and it will allow automated searches among all the
objects and the wide range of wavelengths contained in the vast
array of observations made by LSST and other planned and currently
operational facilities. Collaborations with international partners
should lead to a future global virtual observatory.
Visit
the Official NVO Site
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