Artists concept of an impact crater on Jupiters moon Ganymede, with Jupiter
Artist's concept of an impact crater on Ganymede, about 10 miles in diameter, dominates a scene otherwise defined by a dozen long ridges. In the middle of the crater is a central peak, formed when the energy of the impact liquefied the crust long enough for it to rebound upward and solidify once again.
Immediately above the horizon, Jupiter is still a majestic spectacle, even at a distance of nearly three times that between the Earth and its moon. Much closer on the upper right is Ganymede's sister satellite Europa. At a distance of 307 thousand miles from this vantage point, Europa is only a quarter again as far as the Earth is from its moon. To the lower left of Jupiter at nearly a million miles is Jupiter's volcanic satellite Io.
Jupiter's largest satellite Ganymede has a varying surface, some of which is characterized by rumpled bundles of ridges and grooves that run for hundreds of miles over a frozen surface of water-ice. They probably formed long ago when tectonic forces pulled apart Ganymede's upper crust; similar sets of faults occur in rift zones on Earth, as in eastern Africa. Subsequent meteoritic impacts have peppered, and broken in places, the continuity of the running formations
© Walter Myers/Stocktrek Images
Art of space shuttle exploration
Planetary exploration. Computer artwork depicting the space shuttle being launched to explore the planets of our solar system. The planets are not drawn to scale. The two largest planets are Saturn (left), with its extensive ring system, and Jupiter (right). Earth lies below and between them, with Mars and then Pluto to its left. Below Pluto is Neptune, with the Earth's moon to its right and Venus beneath it. At centre right are Mercury (brown) and Uranus (green/blue). Future space shuttles may be launched into space in order to explore the planets
© VICTOR HABBICK VISIONS/SCIENCE PHOTO LIBRARY
New Horizons spacecraft approaches dwarf planet Pluto and its moon Charon
NASA's New Horizons unmanned spacecraft approaches dwarf planet Pluto and its moon Charon. New Horizons has been en route to Pluto since its launch from Earth in 2006 and is scheduled to make its closest approach on July 14, 2015.
New Horizons is about the size and shape of a grand piano and weighed 1, 054 pounds at launch. The high-gain dish antenna is about 7 feet in diameter and is employed for communication with the Earth.
In this image the New Horizons spacecraft is about 15, 000 miles from Pluto (upper right), 27, 000 miles from its largest moon Charon (lower left) and 2.97 billion miles from the Earth. This side of the spacecraft on the left can be seen the Visible/Near Infrared Multi-Spectral Imager and the Short Wavelength Infrared Spectral Imager (aka Ralph), and the Ultraviolet Imaging Spectrograph (aka Alice). On the right extending about four feet from the main body of the spacecraft is the radioisotope thermoelectric generator (RTG) which provides constant electric power for the 10 year mission from heat produced by 24 pounds of plutonium-238.
While little is known about Pluto's appearance, here this Kuiper belt dwarf planet is realized as a frozen world covered with various ices, hosting a thin atmosphere of nitrogen, methane and other hydrocarbons too possibly, with a significantly weathered surface as Pluto's 248-year orbit alternately brings it closer then further from the warmth of the sun
© Walter Myers/Stocktrek Images