2 posts tagged dust
Explanation: The Whirlpool Galaxy is a classic spiral galaxy. At only 30 million light years distant and fully 60 thousand light years across, M51, also known as NGC 5194, is one of the brightest and most picturesque galaxies on the sky. The aboveimage is a digital combination of a ground-based image from the 0.9-meter telescope at Kitt Peak National Observatory and a space-based image from the Hubble Space Telescope highlighting sharp features normally too red to be seen. Anyone with a good pair of binoculars, however, can see this Whirlpool toward the constellation of the Hunting Dogs (Canes Venatici. M51 is a spiral galaxy of type Sc and is the dominant member of a whole group of galaxies. Astronomers speculate that M51’s spiral structure is primarily due to its gravitational interaction with a smaller galaxy just off the top of the image.
Titan appears to be strung like a bead on Saturn’s rings, which cast shadows onto the southern hemisphere of the gas giant in this beautiful image from Cassini.
Faint but exquisite detail in the gas giant’s upper atmosphere paints a tranquil scene. A thin band of bright white ammonia ice clouds is etched into the planet’s disc towards the top of the image while clouds dotted below are faded scars of a huge storm that raged across the planet through much of 2011.
Shadows cast by Saturn’s iconic rings appear painted onto the planet’s southern hemisphere in two thick bands broken by thin, lighter stripes, reflecting the intricacies of the individual rings. As Saturn’s seasons progress towards northern hemisphere summer, the rings will appear to grow wider and wider.
Meanwhile Titan, Saturn’s largest moon, appears to hang on the planet’s rings like a bead on a necklace. The effect is a result of the line-of-sight viewing position; Titan orbits Saturn at an average distance of 1,221,870 km.
reblogged from unknownskywalker