Archive for October 13th, 2009

When you think of Idaho, what do you think of? Besides potatoes, do you think lava field? No? You should. Also in the second image, when you enlarge the image those are farms below and above. You can even see the road passing through between the farms.

These images were taken with two different satellites and several years apart, the Earth Observing-1 sat and Landstat 7. See details below, and clicking the first image for embiggination isn’t going to work. There is no larger image that I’m aware of, but the second image gives you an idea of the scale.

Acquired September 16, 2009

Craters of the Moon lava field is an accumulation of geologically young lava flows (some only 2,100 years old) spreading over the Snake River Plain. Weathering of the lava flows in arid southeastern Idaho is very slow, so the flows appear similar to when they were first erupted. The bare lava appears dark gray and black in this natural-color satellite image. The brown region encircled by lava is a kipuka, a region of high ground spared from the encroaching lava. Carey Kipuka, to the west of this image, preserves some of the only remaining natural grassland in the Snake River Plain. Most of the other grasslands in the area, including Huddles Hole (shown here), have been changed by grazing and other agriculture.

The entire Snake River Plain is underlain by old lava flows similar to those at Craters of the Moon. Instead of being exposed, the older flows are covered by loess, soil composed of wind-driven silt. The loess accumulated during the last ice age, which ended about 10,000 years ago. Along the southern edge of this scene the 11,000-year old Heifer Reservoir flow is covered with only 5 centimeters (2 inches) of wind-blown sand. Older flows in the area are covered by up to 2 meters (6.6 feet) of sand, volcanic ash, and loess. Where the soil is thick enough, sagebrush grows. Newer flows support only scattered tufts of grass or an occasional tree.

This image was acquired on September 16, 2009, by the Advanced Land Imager aboard the Earth Observing-1 (EO-1) satellite. It has a spatial resolution (level of detail) of ten meters per pixel.

Acquired August 1, 2001

Craters of the Moon lava field is a striking area of recent volcanic activity within Idaho’s Snake River Plain. The 60 (or more) lava flows in the field range from approximately 15,000 to 2,100 years old. Together the flows cover 1,600 square kilometers (620 square miles) with a total volume of 30 cubic km (7.2 cubic miles). A 3-D view of Craters of the Moon shows the Snake River Plain in relation to the adjacent mountains.

This natural-color image of Craters of the Moon was acquired by the Enhanced Thematic Mapper Plus (ETM+) aboard the Landsat 7 satellite on August 1, 2001. The lava flows appear black, dark brown, and even dark blue. Thick vegetation (forest in the Pioneer Mountains and irrigated fields on the Snake River Plain) is green, while the scrubby vegetation surrounding the lava field appears brown. Scrub-covered areas surrounded by lava flows are called kipukas.

U2 visits with NASA mission control in Houston to talk to the ISS crew. With spaceflight participant Guy Laliberté on the phone with U2.

Frank De Winne is honored by European dignitaries because of his new role is ISS commander.

Pictures from the October 11th landing of Soyuz TMA-14, the spacecraft that brought safely back to earth Commander Gennady Padalka of the RKA, Flight Engineer Michael Barratt from NASA, and spaceflight participant Guy Laliberté.

Seated left to right, Spaceflight participant Guy Laliberté, Expedition 20 Commander Gennady Padalka, Expedition 20 Flight Engineer Michael Barratt sit in chairs outside the Soyuz Capsule just minutes they landed near the town of Arkalyk, Kazakhstan on Sunday, Oct. 11, 2009. Padalka and Barratt are returning from six months onboard the International Space Station, along with Laliberté who arrived at the station on Oct. 2 with Expedition 21 Flight Engineers Jeff Williams and Maxim Suraev aboard the Soyuz TMA-16 spacecraft. Photo Credit (All Images): NASA/Bill Ingalls

Volcanoes, you like Volcanoes? I do! Enjoy, details as always below.

After 10 months of relative quiet, Soufriere Hills volcano on the Caribbean island of Montserrat blasted ash into the sky in early October 2009. This natural-color satellite image, acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra spacecraft, shows a plume of ash extending westward from Soufriere Hills on October 12, 2009, a week after eruptive activity resumed on October 5th. According to the U.S. Air Force Weather Agency, ash extended 540 kilometers (330 miles) at an elevation of approximately 4,000 meters (13,000 feet).

Soufriere Hills is a stratovolcano composed of alternating layers of hardened lava, solidified ash, and rocks ejected by previous eruptions. After the seventeenth century, the volcano experienced no recorded eruptions until 1995, when a series of major eruptions eventually forced the evacuation of the Montserrat’s former capital city, Plymouth.

LROC looks at a fresh crater south of Mare Tranquillitatis.

The crater above looks like any ordinary bright spot in lower resolution images, such as those from the Clementine mission (100 m/pixel). However, at high resolution (52 cm/pixel), extraordinary detail is revealed that will help us to better understand the complex series of events that occur during and after an impact event. In the first image, layers of ejecta stream out across the surface. Small craters churn up and expose both the fresh material within the ejecta blanket (those that appear bright) and reveal mature material from beneath it (those that appear dark).

Together with the high spatial resolution of the NAC, the lighting conditions also contribute to make this an especially spectacular view. When LRO initially went into orbit, all of the images were acquired with the sun very low on the horizon, and even small features cast huge shadows. Over the next three months the orbit gradually transitioned to one where the sun was directly overhead at the equator, as in this image where the incidence angle is just two degrees. While low sun images are ideal for interpreting surface texture and topography, the high-sun images that LROC is currently acquiring enhance subtle albedo (brightness) differences on the surface, as can be seen in the the image above showing the jumbled interior of the crater, and the reduced-resolution view of the entire crater below. Many factors determine the reflectance of a surface, including composition, particle size, whether the soil is tightly-packed or loose and fluffy, and how long it has been exposed on the surface. At the site of a fresh impact such as this one, all of these factors can come into play.

Reduced-resolution view of a fresh lunar crater. Scene is 2.5 km across. Credit: NASA/GSFC/Arizona State University.