Proponents of the Precision Tracking Space System were not shy about touting its supposed benefits.
The head of the U.S. Missile Defense Agency said PTSS represented an “unprecedented capability” to protect America and its allies against a nuclear attack by the likes of North Korea and Iran.
A key congressional supporter described it as “a necessity for our country.”
The planned network of nine to 12 satellites, orbiting high above the equator, would detect missile launches and track warheads in flight with great precision, the proponents said.
It would be able to tell apart real missiles from decoys — an elusive capability known as “discrimination.” It would help guide U.S. rocket-interceptors to destroy incoming warheads. And it would do all this at a fraction of the cost of alternative approaches.
Based on those promises, the Obama administration and Congress poured more than $230 million into design and engineering work on PTSS starting in 2009. Four years later, the government quietly killed the program before a single satellite was launched.
The Missile Defense Agency said PTSS fell victim to budget constraints. In fact, the program was spiked after outside experts determined that the entire concept was hopelessly flawed and the claims made by its advocates were erroneous. It was the latest in a string of expensive failures for the missile agency.
The eastern coastline of Mexico's Yucatan Peninsula, a mecca for tourists, may have been walloped by a tsunami between 1,500 and 900 years ago, says a new study involving Mexico's Centro Ecological Akumal (CEA) and the University of Colorado Boulder.
There are several lines of evidence for an ancient tsunami, foremost a large, wedge-shaped berm about 15 feet above sea level paved with washing machine-sized stones, said the researchers. Set back in places more than a quarter of a mile from shore, the berm stretches for at least 30 miles, alternating between rocky headlands and crescent beaches as it tracks the outline of the Caribbean coast near the plush resorts of Playa del Carmen and Cancun.
Radiocarbon dates of peat beneath the extensive berm indicate a tsunami, which may have consisted of two or even three giant waves, likely slammed the coastline sometime after A.D. 450. In addition, ruins of Post-Classic Mayan structures built between A.D. 900 and 1200 were found atop parts of the berm, indicating the tsunami occurred prior to that time.
Catastrophic ice lake collapse in Aram Chaos, Mars
Authors:
Roda et al
Abstract:
Hesperian chaotic terrains have been recognized as the source of outflow channels formed by catastrophic outflows. Four main scenarios have been proposed for the formation of chaotic terrains that involve different amounts of water and single or multiple outflow events. Here, we test these scenarios with morphological and structural analyses of imagery and elevation data for Aram Chaos in conjunction with numerical modeling of the morphological evolution of the catastrophic carving of the outflow valley. The morphological and geological analyses of Aram Chaos suggest large-scale collapse and subsidence (1500 m) of the entire area, which is consistent with a massive expulsion of liquid water from the subsurface in one single event. The combined observations suggest a complex process starting with the outflow of water from two small channels, followed by continuous groundwater sapping and headward erosion and ending with a catastrophic lake rim collapse and carving of the Aram Valley, which is synchronous with the 2.5 Ga stage of the Ares Vallis formation. The water volume and formative time scale required to carve the Aram channels indicate that a single, rapid (maximum tens of days) and catastrophic (flood volume of 9.3?104 km3) event carved the outflow channel. We conclude that a sub-ice lake collapse model can best explain the features of the Aram Chaos Valley system as well as the time scale required for its formation.
A geologic scar left by a catastrophic Texas flood in 2002 is providing an unexpected scientific benefit. A new study demonstrates how researchers can use a channel carved by floodwaters pouring over the dam of a flooded reservoir as a laboratory to test scientific theories of how such canyons are formed. The research could help to inform the hydrological histories of Earth and Mars by indicating the kind of imprints large, sudden floods leave on a planet's surface.
The storm that struck central Texas eight years ago wreaked havoc on the region, which President George W. Bush declared a disaster area. Floodwaters killed 12 people and damaged 48,000 homes in dozens of counties, according to a report from the U.S. Geological Survey (USGS). At Canyon Lake, a reservoir north of San Antonio, water rushed over the dam's spillway, pouring into the valley below. Within days a 50-meter-wide channel now known as the Canyon Lake Gorge had been carved into the soil and bedrock, drastically transforming the landscape on a short timescale.
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New research indicates that one of the largest fresh-water floods in Earth's history happened about 17,000 years ago and inundated a large area of Alaska that is now occupied in part by the city of Wasilla, widely known because of the 2008 presidential campaign.
The event was one of at least four "megafloods" as Glacial Lake Atna breached ice dams and discharged water. The lake covered more than 3,500 square miles in the Copper River Basin northeast of Anchorage and Wasilla.
The megaflood that covered the Wasilla region released as much as 1,400 cubic kilometers, or 336 cubic miles, of water, enough to cover an area the size of Washington, D.C., to a depth of nearly 5 miles. That water volume drained from the lake in about a week and, at such great velocity, formed dunes higher than 110 feet, with at least a half-mile between crests. The dunes appear on topographical maps but today are covered by roads, buildings and other development.
"Your mind doesn't get around dunes of that size. Obviously the water had to be very deep to form them," said Michael Wiedmer, an Anchorage native who is pursuing graduate studies in forest resources at the University of Washington.
Wiedmer is the lead author of a paper describing the Wasilla-area megaflood, published in the May edition of the journal Quaternary Research. Co-authors are David R. Montgomery and Alan Gillespie, UW professors of Earth and space sciences, and Harvey Greenberg, a computer specialist in that department.
By definition, a megaflood has a flow of at least 1 million cubic meters of water per second (a cubic meter is about 264 gallons). The largest known fresh-water flood, at about 17 million cubic meters per second, originated in Glacial Lake Missoula in Montana and was one of a series of cataclysmic floods that formed the Channeled Scablands of eastern Washington.
The megaflood from Glacial Lake Atna down what is now the Matanuska River to the Wasilla region might have had a flow of about 3 million cubic meters per second. Another suspected Atna megaflood along a different course to the Wasilla region, down the Susitna River, might have had a flow of about 11 million cubic meters per second. The researchers also found evidence for two smaller Atna megafloods, down the Tok and Copper rivers.
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