Image credit: ESA
View from overhead of the complex caldera (summit crater) at the summit of Olympus Mons on Mars, the highest volcano in our Solar System.
Olympus Mons has an average elevation of 22 km and the caldera has a depth of about 3 km. This is the first high-resolution colour image of the complete caldera of Olympus Mons.
The image was taken from a height of 273 km during orbit 37 by the High Resolution Stereo Camera (HRSC) on ESA?s Mars Express on 21 January 2004. The view is centred at 18.3?N and 227?E. The image is about 102 km across with a resolution of 12 m per pixel. South is at the top.
This complementary 3D view shows the Olympus Mons volcano in its entirety, to put the caldera images in context. It has been derived from the Mars Orbiter Laser Altimeter (MOLA) topographic data superimposed with the Mars Orbiter Camera (MOC) wide-angle image
Original Source: ESA News Release
Image credit: Hubble
A collision of two galaxies has left a merged star system with an unusual appearance as well as bizarre internal motions. Messier 64 (M64) has a spectacular dark band of absorbing dust in front of the galaxy’s bright nucleus, giving rise to its nicknames of the “Black Eye” or “Evil Eye” galaxy.
Fine details of the dark band are revealed in this image of the central portion of M64 obtained with the Hubble Space Telescope. M64 is well known among amateur astronomers because of its appearance in small telescopes. It was first cataloged in the 18th century by the French astronomer Messier. Located in the northern constellation Coma Berenices, M64 resides roughly 17 million light-years from Earth.
At first glance, M64 appears to be a fairly normal pinwheel-shaped spiral galaxy. As in the majority of galaxies, all of the stars in M64 are rotating in the same direction, clockwise as seen in the Hubble image. However, detailed studies in the 1990’s led to the remarkable discovery that the interstellar gas in the outer regions of M64 rotates in the opposite direction from the gas and stars in the inner regions.
Active formation of new stars is occurring in the shear region where the oppositely rotating gases collide, are compressed, and contract. Particularly noticeable in the image are hot, blue young stars that have just formed, along with pink clouds of glowing hydrogen gas that fluoresce when exposed to ultraviolet light from newly formed stars.
Astronomers believe that the oppositely rotating gas arose when M64 absorbed a satellite galaxy that collided with it, perhaps more than one billion years ago. This small galaxy has now been almost completely destroyed, but signs of the collision persist in the backward motion of gas at the outer edge of M64.
This image of M64 was taken with Hubble’s Wide Field Planetary Camera 2 (WFPC2). The color image is a composite prepared by the Hubble Heritage Team from pictures taken through four different color filters. These filters isolate blue and near-infrared light, along with red light emitted by hydrogen atoms and green light from Str?mgren y.
Original Source: Hubble News Release
Here’s a 1024×768 resolution wallpaper of the amazing first photograph of Mars taken by the European Space Agency’s Mars Express spacecraft. The stereoscopic image was taken on January 14, 2004 by Mars Express when it was 275 kilometres above the Valles Marineris – a 1700 km long by 65 km wide canyon that runs across the surface of Mars.
This image mosaic was taken by the Mars Spirit rover while it was still sitting on its landing platform – the direction is to the southwest of the landing site. The landscape is very flat, scattered with small rocks and occasional shallow depressions; the narrow peak of a hill is visible seven to eight kilometres away. The image was taken using Spirit’s Panoramic Camera.