FIGURE 3.1 An example of the Hubble Space Telescope’s superior resolution compared with that of a standard ground-based telescope: (left) a distant, peculiar interacting galaxy imaged with the Subaru telescope on Mauna Kea; (right) the same object imaged with Hubble. Subaru (8 m) telescope image courtesy of National Astronomical Observatory of Japan; Hubble (2.4 m) image courtesy of STScI/NASA.

FIGURE 3.2 Two Hubble Space Telescope images illustrate the value of observing at different wavelengths. (left) An image obtained at near-infrared wavelengths, which penetrate the dust, reveals hundreds of stars in the region, as well as a large complex of newly forming stars deep within the dusty column itself. (right) An image obtained at visible wavelengths shows a column of obscuring dust and gas in the famous Eagle nebula (M16). The sculpting away of the dust by an intense rain of radiation from nearby hot stars (off image to top) reveals denser globules of gas inside the column that are seen as protuberances on the surface of the cloud. These protuberances are likely sites of star formation.

Each wavelength imaged by Hubble provides unique information about the sources studied. Images courtesy of STScI/NASA.