Shiny Polar Clouds

A NASA satellite has captured the first occurrence of mysterious shiny polar clouds that form 50 miles above Earth's surface. The AIM (Aeronomy of Ice in the Mesosphere) spacecraft returned some of the first data on these noctilucent or "night shining" clouds on June 11, 2007. In this image of the Arctic regions of Europe and North America, white and light blue represent noctilucent cloud structures. Black indicates areas where no data is available.
The clouds form in an upper layer of the Earth’s atmosphere called the mesosphere during the Northern Hemisphere’s summer season which began in mid-May and extends through the end of August and are being seen by AIM’s instruments more frequently as the season progresses. They are also seen in the high latitudes during the summer months in the Southern Hemisphere.
Very little is known about how these clouds form over the poles, why they are being seen more frequently and at lower latitudes than ever before, or why they have been growing brighter. AIM will observe two complete cloud seasons over both poles, documenting an entire life cycle of the shiny clouds for the first time.
AIM is providing scientists with information about how many of these clouds there are around the world and how different they are including the sizes and shapes of the tiny particles that make them up. Scientists believe that the shining clouds form at high latitudes early in the season and then move to lower latitudes as time progresses. The AIM science team is studying this new data to understand why these clouds form and vary, and if they may be related to global change.
Image credit: Cloud Imaging Team, U. of Colorado/NASA

Volcano

On March 29, 2007, the Shiveluch Volcano on the Russian Federation's Kamchatka Peninsula erupted, sending an ash cloud skyward roughly 9,750 meters (32,000 feet).
Satellites often capture images of volcanic ash plumes, but usually as the plumes are blowing away. This image, however, is different. It shows the gray-brown ash cloud suspended directly over the summit. At the time the Aqua satellite passed overhead, the local air was still enough to let the ash cloud hover. In this image, the bulbous cloud casts its shadow northward over the icy landscape.
Volcanic ash eruptions inject particles into Earth's atmosphere; substantial eruptions of light-reflecting particles can reduce temperatures and even affect atmospheric circulation. Large eruptions may impact climate patterns for years. A massive eruption of the Tambora Volcano in Indonesia in 1815, for instance, earned 1816 the nickname "the year without a summer."
Shiveluch is a stratovolcano -- steep-sloped volcano composed of alternating layers of solidified ash, hardened lava and volcanic rocks. One of Kamchatka's largest volcanoes, it sports a summit reaching 3,283 meters (10,771 feet). Shiveluch is also one of the peninsula's most active volcanoes, with an estimated 60 substantial eruptions in the past 10,000 years.
Image credit: NASA/GSFC/MODIS Rapid Response Team

The Thames flows through the North Sea!

Muddy Thames water leaves a visible trail as it meanders past the coasts of Belgium, the Netherlands, Germany and towards the Danish coast. Image from NASA's Terra satellite, 26 March 2007.