Space at
your fingertips.
"I want to know why the universe exist, why there is something greater than nothing."
Steven Hawking
Scientist, Space Lover
Skylab was an orbiting laboratory launched by a Saturn V rocket in May 1973. Skylab, pictured above, was visited three times by NASA astronauts who sometimes stayed as long as two and a half months. Many scientific tests were performed on Skylab, including astronomical observations in ultraviolet and X-ray light. Some of these observations yielded valuable information about Comet Kohoutek, our Sun and about the mysterious X-ray background - radiation that comes from all over the sky. Skylab fell back to earth on 11 July 1979.
The deeper you peer into the universe, the harder it is to see straight. The reason is that distant galaxies act as gravitational lenses, deflecting light that passes nearby. These deflections result in the distortion of background sources, and in some cases the creation of multiple images. Pictured above, candidate artifacts of gravitational lensing have been found in images from the Medium Deep Survey being done with the Hubble Space Telescope. Background source images that are lensed by foreground galaxies include quasars, appearing as multiple blue smudges, and galaxies, distorted into curving arcs. Unusual and interesting candidates for gravitational lensing include an edge-on galaxy disk which might be acting as a lens (upper left) and an image nicknamed London Underground (far left) which could well be the distortion of a background galaxy into an optical Einstein ring.
The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, the umbra has a circular cross section that can be most easily seen during a lunar eclipse. For example, last Saturday the Full Moon slid across the northern edge of the umbra. Entertaining moon watchers throughout Earth's eastern hemisphere, the lunar passage created a deep but partial lunar eclipse. This composite image uses successive pictures recorded during the eclipse from Athens, Greece to trace out a large part of the umbra's curved edge. The result nicely illustrates the relative size of the umbra's cross section at the distance of the Moon, as well as the Moon's path through the Earth's shadow.
Expanse