'Crater' spied under California

[coughymachine]

According to the International Herald Tribune...

In 1998, Congress gave NASA's Spaceguard Survey program a mandate of "discovering, tracking, cataloging and characterizing" 90 percent of the near-Earth objects larger than one kilometer (3,200 feet) wide by 2008. An object that size would probably destroy civilization.

However...

Realizing that there are many smaller but still terribly destructive asteroids out there, Congress has modified the Spaceguard goal to identify 90 percent of even smaller objects — 460 feet and larger — by 2020. This revised survey, giving us decades of early warning, will go a long way toward protecting life on the planet in the future.

Fortunately...

...scientists feel we have the technology to intercept and deflect many asteroids headed toward Earth.

Perhaps less fortunately...

...scientists haven't had a chance to try it in practice. And this is where NASA's report was supposed to come in. Congress directed the agency in 2005 to come up with a program, a budget to support it and an array of alternatives for preventing an asteroid impact.

But instead of coming up with a plan and budget to get the job done, the report bluntly stated that "due to current budget constraints, NASA cannot initiate a new program at this time."

This article from the BBC reminds us that our planet has long been pummeled by meteors and asteroids, and makes me think that perhaps NASA should get those budget constraints lifted.

'Crater' spied under California

By Paul Rincon

Science reporter, BBC News, Houston

Oil exploration work in California's Central Valley region has uncovered a possible space impact crater.

A seismic survey peels away the sediments to reveal the structure

The 5.5km-wide bowl is buried under shale sediments west of Stockton, in San Joaquin County, and is thought to be between 37 and 49 million years old.

Researchers are continuing to analyse cuttings from oil exploration wells drilled in the structure.

Details of the discovery were presented at the Lunar and Planetary Science Conference in Houston.

Data from a 3D seismic survey of an ancient sea bed clearly shows a circular structure buried 1,490-1,600m (4,890-4,250ft) below sea level.

The Victoria Island structure, as it has been named, has a concentric rim surrounding a "central uplift" - a peak at the centre - which are both characteristic of impact craters.

Co-investigator Professor Jared Morrow, from San Diego State University, said the context of the crater in relation to surrounding rock layers suggested it dated from the middle Eocene Epoch.

Crater pair

Preliminary estimates for the age of the crater suggest it is just too early for an episode of multiple impacts on Earth known as the late Eocene bombardment, which occurred about 35 million years ago.

One of the largest impact craters in the world - the 45km-wide (28 miles) Chesapeake Bay structure on the eastern shore of North America - is from this period.

"It would be interesting if our crater dated to that time, but we can't make that association at the moment," said co-author Dr Morrow, an assistant professor at San Diego State University.

The team plans to look for characteristic geological signatures of impact sites in cuttings drilled from wells in and around the structure.

These include a type of quartz deformed under intense pressure - known as shocked quartz - as well as glass and melt particles, and an enhancement of the element iridium.

Victoria Island is not the first crater proposed for the Central Valley. A 1.3km-wide (0.8 miles) feature to the north known as the Cowell structure, dating to the Miocene (5 to 24 million years ago), has also been put forward as the location of a space impact.

Dr Morrow co-authored the work with Samuel Spevack from Grossmont Middle College High School, in California, and Bennett Spevack from ABA Energy.

Several more images of this 'crater' can be found here.

[Pax Unum]

the report bluntly stated that "due to current budget constraints, NASA cannot initiate a new program at this time."

funny, when you think of the things the government CAN find money for in the budget...