A parallel Worlds

Tuesday September 18 2007 / Science & Technology

To Fly Free in Space. Credit: STS-41B and NASA. Please click on the image for a larger version.

At about 100 meters from the cargo bay of the space shuttle Challenger, Bruce McCandless II was further out than anyone had ever been before. Guided by a Manned Maneuvering Unit (MMU), astronaut McCandless, pictured above, was floating free in space. McCandless and fellow NASA astronaut Robert Stewart were the first to experience such an "untethered space walk" during Space Shuttle mission 41-B in 1984.

The MMU works by shooting jets of nitrogen and has since been used to help deploy and retrieve satellites. With a mass over 140 kilograms, an MMU is heavy on Earth, but, like everything, is weightless when drifting in orbit. The MMU was replaced with the SAFER backpack propulsion unit. Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)

Tentacles of the Tarantula Nebula. Credit & Copyright: WFI, MPG/ESO 2.2-m Telescope, La Silla, ESO. Please click on the image for a larger version.

The largest, most violent star forming region known in the whole Local Group of galaxies lies in our neighboring galaxy the Large Magellanic Cloud (LMC). Were the Tarantula Nebula at the distance of the Orion Nebula -- a local star forming region -- it would take up fully half the sky. Also called 30 Doradus, the red and pink gas indicates a massive emission nebula, although supernova remnants and dark nebula also exist there.

The bright knot of stars left of center is called R136 and contains many of the most massive, hottest, and brightest stars known. The above image taken with the European Southern Observatory's (ESO's) Wide Field Imager is one of the most detailed ever of this vast star forming region. ESO has made it possible to fly around and into this detailed image by clicking here.

South Pole Lunar Eclipse. Credit & Copyright: Robert Schwarz (South Pole Station). Please click on the image for a larger version.

The Moon was up continuously for 14 days in August -- when viewed from the South Pole. But during the total lunar eclipse on August 28, it circled only about 10 degrees above the horizon. For Robert Schwarz, the resulting long line-of-sight through the atmosphere that blurred his images was a minor problem when he recorded this four hour long lunar eclipse sequence. A more severe problem was the outdoor air temperature of -68 C (-90 F).

The extreme cold required him to make the series of exposures through a slit in a window from inside a heated room. Though the heat produced convection and further blurring, it was the only way to keep the camera at a reasonable operating temperature for an extended period of time. Still, he was rewarded with this impressive record of August's lunar eclipse from a unique perspective on planet Earth.

For more information on these images and the technology involved, please click on the images and/or visit the NASA Astronomy Picture of the Day Archive

Suggested by
Ian Skellern