26 March 2013

Congress on Meteors & Asteroids


See archived webcast and the opening statement by Dr. Lamar Smith

Statement of Chairman Lamar Smith (R-Texas)
Hearing on Space Threats: A Review of U.S. Government Efforts to Track and Mitigate Asteroids and Meteors, Part I
Chairman Smith: Good morning. Today’s hearing is on a subject important to our nation and to our world. This is the first hearing of two on Space Threats to Earth, reviewing U.S. Government efforts to track incoming asteroids and meteors.
Although many may be only aware of this subject due to recent events, it is actually one as old as our planet. This is a copy of TIME Magazine from nearly 20 years ago (1994) where this topic was featured on the cover. Though the issue has been around for a number of years, there are many questions still to be asked and answered. The range of questions are broad and complex, from how to track an object millions of miles away to how to respond if an asteroid or meteor is headed toward Earth.
The two events of Friday, February 15 - the harmless flyby of asteroid 2012 DA14 and the not so harmless impact of a meteor in Russia - are a stark reminder of the need to invest in space science. The asteroid passed just 17,000 miles from Earth, a distance less than the Earth’s circumference. Fifty years ago, we would have had no way of seeing the asteroid coming, and even so it was discovered by amateur astronomers. The U.S. has come a long way in its ability to track and characterize asteroids, meteors, comets and meteorites. But we still have a long way to go. NASA believes it has discovered 93 percent of the largest asteroids in near-Earth orbit, those one kilometer or larger.
But what about the other seven percent remaining, about 70, or even those smaller than one kilometer, estimated to be in the thousands? An asteroid as small as 100 meters could destroy an entire city upon a direct hit. Are we tracking those?The meteor that struck Russia was estimated to be 17 meters, and wasn’t tracked at all. The smaller they are, the harder they are to spot, and yet they can be life-threatening. The broad scope of our efforts include participation of governments, research institutions, industries and amateur astronomers in their backyard or on home computers.
Some space challenges require innovation, commitment and diligence. This is one of them. And this Committee will strive to continue to lead in this area. For all of the attention and publicity the two events of February 15 received, it was still too late for us to have acted to change the course of the incoming objects. We are in the same position today and for the foreseeable future unless we take actions now that improve our means of detection. Part of our discussion today is about how to achieve this in the current budget environment.
I do not believe that NASA is going to somehow defy budget gravity and get an increase when everyone else is getting cuts. But we need to find ways to prioritize NASA’s projects and squeeze as much productivity as we can out of the funds we have.
Examining and exploring ways to protect the Earth from asteroids and meteors is a priority for the American people and should be a priority for NASA. We were fortunate that the events of last month were simply an interesting coincidence rather than a catastrophe.
However, we still need to make investments and improvements in our capability to anticipate what may
occur decades from now, or tomorrow.


Smith: Avoiding Asteroid Threats Requires Innovation, Commitment and Diligence

Mar 19, 2013

Washington, D.C. – The House Science, Space, and Technology Committee today held a hearing titled, Threats from Space: A Review of U.S. Government Efforts to Track and Mitigate Asteroids and Meteors. The hearing is the first in a two-part series on what the U.S. is doing to track and monitor Near Earth Objects (NEO) that pose a threat to the planet. It comes one month after an asteroid passed the earth and a meteor exploded over the skies in Russia on the same day.

Chairman Smith: “The meteor that struck Russia was estimated to be 17 meters, and wasn’t tracked at all. The smaller they are, the harder they are to spot, and yet they can be life-threatening. Some space challenges require innovation, commitment and diligence. This is one of them.

“Examining and exploring ways to protect the Earth from asteroids and meteors is a priority for the American people and should be a priority for government. We were fortunate that the events of last month were simply an interesting coincidence rather than a catastrophe. And this Committee will strive to continue to lead in this area.”

On February 15, 2013, an unforeseen meteor exploded above Russia, releasing the equivalent of about 20 times the explosive energy of an atomic bomb. The blast injured nearly 1,200 people and resulted in an estimated $33 million in property damage. Until it entered our atmosphere, the Russian meteor went completely undetected. On the same day, a larger asteroid discovered by amateur astronomers and tracked closely by NASA passed safely by the Earth, but within the orbital belt of weather satellites.

Today’s hearing provided an overview of the U.S. government’s plans and programs to track, classify and mitigate the threat of NEOs. Witnesses estimated that between 13,000 and 20,000 objects exist that are over 140 meters and considered “near Earth.” Of those objects, we only have knowledge of and track around 10 percent. In order to improve on these capabilities, witnesses discussed the need for better international collaboration and more space-borne telescopes to track NEOs.

A second hearing is planned for April to address international, commercial private sector and philanthropic initiatives to survey the sky for asteroids and comets.

The following witnesses testified today:
The Honorable John P. Holdren, Director, Office of Science and Technology Policy, Executive Office of the President
Gen. William L. Shelton, Commander, U.S. Air Force Space Command
The Honorable Charles F. Bolden, Jr., Administrator, National Aeronautics and Space Administration

We’re on notice to plan for the next meteor

By Rush Holt and Donna F. Edwards,February 15, 2013
Rush Holt (D) is a physicist and former assistant director of the Princeton Plasma Physics Laboratory. He represents New Jersey’s 12th District in the U.S. House. Donna F. Edwards, who represents Maryland’s 4th District, is the ranking Democrat on the House subcommittee on space.
Ameteor broke apart over rural Russia on Friday morning, injuring at least 1,200 people. Hours later, an asteroid known as 2012 DA14 passed about 17,000 miles above Earth’s surface — a close shave in astronomical terms, passing nearer than many of our communications satellites. One was predicted; the other was not.
These events were unrelated, but they underscore how crucial it is that nations know, quickly, what is falling from the sky and what, if any, dangers are posed.
Every day about 40 tons of space debris hit the atmosphere, burn and settle to Earth, NASA has found. The vast majority of the detritus consists of meteoroids no larger than a grain of sand, but even tiny specks pack a wallop: A typical meteor hits Earth traveling at least seven miles per second, at least 30 times faster than a bullet shot from a handgun. That is why a tiny meteoroid can make such a spectacular shooting star.
According to the Russian Academy of Sciences, the meteor that disintegrated over Siberia on Friday weighed in the neighborhood of 10 tons. It was thought to be traveling at 10 to 12 miles per second when it broke apart.
Every year or so, such a meteor blazes through the sky somewhere over Earth. But every 100 years or so, Earth is hit by a meteor large enough to cause much more significant devastation. Such an impact occurred in 1908 in Tunguska, Russia, when a meteor 100 feet or so in diameter exploded in the Siberian wilderness, releasing about 1,000 times the amount of energy as the nuclear bomb dropped on Hiroshima.
And every 100 million years or so, Earth is hit by a meteor large enough to cause mass extinctions, like the one at the end of the age of dinosaurs. These threats are minuscule on a day-to-day basis, but surely any existential threat to the human race must be taken seriously.
To help get a handle on this danger, NASA coordinates the Near-Earth Object Program, which searches for and tracks asteroids and comets that could approach the earth. As of this week, about 10,000 near-Earth objects have been discovered, including nearly 900 with a diameter of roughly a kilometer or larger. None is expected to hit Earth anytime soon, but many large objects are believed to remain undetected.
In 2005 Congress set a 15-year deadline for scientists to find 90 percent of the near-Earth objects greater than about 500 feet in diameter — those large enough to cause regional or global devastation. But the mandate has been chronically underfunded. The project would require several more dedicated telescopes. Last year the project received about $20 million, far less than the $50 million that the National Research Council estimated in 2010 was needed to reach the congressional goal by 2030, a decade late. Even when this goal is met, most small asteroids and comets — too small to cause global devastation but still large enough to cause damage far worse than just occurred in Russia — will remain undetected unless funding is significantly increased.

Algae-like structures inside a Sri Lankan meteorite are clear evidence of panspermia

From: http://www.technologyreview.com/view/512381/astrobiologists-find-ancient-fossils-in-fireball-fragments/?goback=%2Emid_I471135276*416_*1
Astrobiologists Find Ancient Fossils in Fireball Fragments

Algae-like structures inside a Sri Lankan meteorite are clear evidence of panspermia, the idea that life exists throughout the universe, say astrobiologists.

On 29 December 2012, a fireball lit up the early evening skies over the Sri Lankan province of Polonnaruwa. Hot, sparkling fragments of the fireball rained down across the countryside and witnesses reported the strong odour of tar or asphalt.

Over the next few days, the local police gathered numerous examples of these stones and sent them to the Sri Lankan Medical Research Institute of the Ministry of Health in Colombo. After noticing curious features inside these stones, officials forwarded the samples to a team of astrobiologists at Cardiff University in the UK for further analysis.

The results of these tests, which the Cardiff team reveal today, are extraordinary. They say the stones contain fossilised biological structures fused into the rock matrix and that their tests clearly rule out the possibility of terrestrial contamination.

In total, Jamie Wallis at Cardiff University and a few buddies received 628 stone fragments collected from rice fields in the region. However, they were able to clearly identify only three as possible meteorites.

The general properties of these three stones immediately mark them out as unusual. One stone, for example, had a density of less than 1 gram per cubic centimetre, less than all known carbonaceous meteorites. It had a partially fused crust, good evidence of atmospheric heating, a carbon content of up to 4 per cent and contained an abundance of organic compounds with a high molecular weight, which is not unknown in meteorites. On this evidence, Wallis and co think the fireball was probably a small comet.

The most startling claims, however, are based on electron microscope images of structures within the stones (see above). Wallis and co. say that one image shows a complex, thick-walled, carbon-rich microfossil about 100 micrometres across that bares similarities with a group of largely extinct marine dinoflagellate algae.
They say another image shows well-preserved flagella that are 2 micrometres in diameter and 100 micrometres long. By terrestrial standards, that’s extremely long and thin, which Wallis and co. interpret as evidence of formation in a low-gravity, low-pressure environment.

Wallis and co. also measured the abundance of various elements in the samples to determine their origin. They say that low levels of nitrogen in particular rule out the possibility of contamination by modern organisms which would have a much higher nitrogen content. The fact that these samples are also buried within the rock matrix is further evidence, they say.

Wallis and co. are convinced that the lines of evidence they have gathered are powerful and persuasive. “This provides clear and convincing evidence that these obviously ancient remains of extinct marine algae found embedded in the Polonnaruwa meteorite are indigenous to the stones and not the result of post-arrival microbial contaminants,” they conclude.

There’s no question that a claim of this kind is likely to generate controversy. Critics have already pointed out that the stones could have been formed by lightning strikes on Earth although Wallis and co. counter by saying there was no evidence of lightning at the time of the fireball and that in any case, the stones do not bear the usual characteristics of this kind of strike. What’s more, the temperatures generated by lightning would have destroyed any biological content.

Nevertheless, extraordinary claims require extraordinary evidence and Wallis and co. will need to make their samples and evidence available to the scientific community for further study before the claims will be taken seriously.

If the paper is taken at face value, one obvious question that arises is where these samples came from. Wallis and c.o have their own ideas: “The presence of fossilized biological structures provides compelling evidence in support of the theory of cometary panspermia first proposed over thirty years ago,” they say.

This is an idea put forward by Fred Hoyle and Chandra Wickramasinghe, the latter being a member of the team who has carried out this analysis.

There are other explanations, of course. One is that the fireball was of terrestrial origin, a remnant of one of the many asteroid impacts in Earth’s history that that have ejected billions of tonnes of rock and water into space, presumably with biological material inside. Another is that the structures are not biological and have a different explanation.

Either way, considerably more work will have to be done before the claims from this team can be broadly accepted. Exciting times ahead!Ref: arxiv.org/abs/1303.1845: The Polonnaruwa Meteorite: Oxygen isotope, Crystalline and Biological Composition

Russia mulls beacons and the bomb to thwart asteroids

From: http://www.spacedaily.com/reports/Russia_mulls_beacons_and_the_bomb_to_thwart_asteroids_999.html

Russia mulls beacons and the bomb to thwart asteroids
by Staff Writers
Moscow (AFP) March 12, 2013

Russian officials on Tuesday proposed ideas ranging from planting beacon transmitters on asteroids to megaton-sized nuclear strikes to avert the threat from meteor collisions with the Earth.

Saving the world from asteroid strikes has moved out of the realm of science fiction in Russia into a political reality after a spectacular meteor explosion injured over 1,500 people in the Russian Urals in February.

The meteor strike over the Russian city of Chelyabinsk raised fears of what could happen if an even larger space body entered the earths atmosphere above an inhabited area.

Russian space agency chief Vladimir Popovkin told a special conference at the Federation Council, the Russian upper house, that Russia was closely following the asteroid Apophis that is due to come close to the Earth in 2036.
"We want to put a beacon on the asteroid Apophis to ascertain its exact orbit and work out what further actions to take with respect to the asteroids approach to the Earth in 2036," he said quoted by Russian news agencies.

NASA has already said that according to its calculations there is no danger of the asteroid colliding with the Earth.

Popovkin said that an initial state plan to combat threats from space could appear in Russia at the end of 2013 but the first real measures would only be adopted no earlier than 2018-2020.

He did not give details on the cost of the programme, although Russian news agencies said previous estimates had been around 58 billion rubles ($1.9 billion).
A senior official from Russias nuclear agency Rosatom told the same conference that taking out an asteroid with a nuclear weapon would require a bomb with a force of at least one megaton.

"Intercepting an asteroid of a span of more than one kilometre would need the use of nuclear material of the power of over a megaton," said Oleg Shubin, the deputy director of the department of nuclear munitions experiments at Rosatom.

"This is a separate scientific task that needs to be solved," he added

Shubin said that it could not be predicted well in advance when some 50 percent of asteroids and meteors in the tails of comets would be on a collision course with the earth.

He said while the probability of an asteroid collision was low it could still happen at any time.

"In the foreseeable future I cannot see any other danger that would lead - at the very least - to the disintegration of human civilisation," Shubin said.

Likely 3 Earth-like planets within 7 Light Years!

"…We now estimate that if we were to look at 10 of the nearest small stars we would find about four potentially habitable planets, give or take," said Ravi Kopparapu, a post-doctoral researcher in geosciences. "That is a conservative estimate," he added. "There could be more…."

…According to his findings, "The average distance to the nearest potentially habitable planet is about seven light years. That is about half the distance of previous estimates," Kopparapu said. "There are about eight cool stars within 10 light-years, so conservatively, we should expect to find about three Earth-size planets in the habitable zones."…