Astronomy Today 4E CW Chapter 5 -- Destinations

Chapter 5: Telescopes
Destinations

No matter how hard we try, and despite the many other online sections and resources here, there will always be more information available in the world than can be contained on one server.

Here are our favorites for this chapter. Go ahead and check them out, but be sure to return back to do more exploring when you're done!

For a good selection of general sites of broad interest and utility that are related to many chapters of the book, see our collection of General Web Destinations for All Chapters.

Telescope Tutorial: This site gives a short introduction to the different kinds of telescopes used in astronomy, both for personal observation and for research.
Buying a First-Time Telescope: From the Public Information Office at McDonald Observatory, this link gives just what you want: a description of the essential features of basic telescope models, recommendations for low to medium price range options, and information on how to learn more before making a selection. See also the related and complementary links Selecting a Telescope and So, You Want to Buy a Telescope.
Everything You Wanted to Know about the Hubble Telescope, But Were Afraid to Ask: This multiple set of pages gives a great overall introduction to the history, layout, performance, and capabilities of the Hubble Space Telescope. Diagrams, links to resources for the related site for the PBS series on Mysteries of Deep Space, images, and even some technical data are provided. You can even find out where the Hubble is right now!
The Space Infrared Telescope Facility: The newest of NASA's "Great Observatories", SIRTF will be to infrared observations what the Hubble Space Telescope is to visible-light astronomy. Scheduled for launch April 18, 2003.
Hubble Goes to the Limit in Search of Farthest Galaxies in 1998: According to Hubble Space Telescope News, Press Release Number STScI-PR98-32, the NASA Hubble Space Telescope has achieved a view of the faintest galaxies ever seen in the universe. The view was taken in infrared light with the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). Though most of these galaxies were first seen in 1995 when Hubble was used to take a visible-light deep exposure of the same field, NICMOS has uncovered many new objects. Astronomers believe that some of these galaxies could be over 12 billion light years away (depending on cosmological models), making them the farthest objects ever seen. A powerful new generation of telescopes will be needed to confirm the suspected distances. Scheduled for launch in 2007, the Next Generation Space Telescope (NGST) will be used to take infrared spectra of candidate galaxies to confirm their distances, and its higher resolution will help reveal the shapes of these early objects.
An Introduction to Light Pollution: An introduction to the very serious problem of light pollution, which interferes with much ground-based astronomy and limits access to the sky for city dwellers in particular, from the International Dark-Sky Association.
The New England Light Pollution Advisory Group: Another excellent introduction, also with proposed solutions, to the problem of wasted outdoor nighttime lighting. Efficient, glare-free lights that are directed only onto the surface that needs illumination can save money, improve aesthetics, and reduce stray light all at the same time.
What Is Adaptive Optics?: An extremely complete online introduction to adaptive optics, with references, written by N. Hubin and L. Noethe of the European Southern Observatory. Research in adaptive optics has the potential to improve the performance of both Earthbound and orbiting telescopes dramatically, opening literally whole new worlds and other aspects of the universe to our vision for the first time. Learn more from this introductory tutorial.
What Is Imaging Radar?: Radar images of a surface are acquired using a radio-frequency-sensitive "telescope" pointing toward the surface that also has to transmit the radio wave pulses that it eventually receives. An imaging radar therefore works much like a flash camera in that it provides its own "light" to illuminate an area on the surface to take pictures, but at radio wavelengths. Images taken with different radar polarizations and/or at different wavelengths can be combined to produce "false-color" pictures for better visualization and contrast. This page gives an indroduction, along with some illustrative diagrams. Follow the links to learn more and to find synthetic-aperture radar images and videos, or go directly to the Imaging Radar Virtual Classroom.
Information and On-line Data in Astronomy: A wide-ranging index of on-line databases that give interactive access to data from many large telescope and satellite facilities via the World Wide Web. Includes summary descriptions of the data archiving systems for these facilities. The sites pointed to by this index are, in general, quite technically oriented, so this is not a destination of choice for casual image browsing.
The Bradford Robotic Telescope: The Bradford Robotic Telescope is a totally autonomous 46 cm telescope located high on the moors in West Yorkshire, England. The telescope decides when the conditions are good enough to make observations of the sky by itself; an astronomer does not need to be present and waste time waiting for clear weather. Anyone on the Internet can register and ask the telescope to look at anything in the northern night sky. Observations are automatically prioritized, scheduled, and completed by the telescope as time allows.
The Reuven Ramaty High Energy Solar Spectroscopic Imager: NASA's newest solar observatory is a satellite named RHESSI, the Reuven Ramaty High Energy Solar Spectroscopic Imager. Designed to image the highest-energy processes in the solar system, solar flares, RHESSI (pronounced "ressy") collects X-rays and gamma rays from the Sun's outer atmosphere. Since these kinds of light can't easily be focused by a lens or a mirror, the reconstruction of images is pretty difficult. Visit the RHESSI site to learn more about the Sun, solar flares, gamma ray telescopes, and the connection to magnetic storms on Earth.