This area will cover relevant news of the threat to the planet from Near Earth Objects (NEOs) including concepts and designs for mitigation. All opinions are those of the author.

26 December 2008

Article: China starts building world's largest radio telescope

From the article...

GUIYANG, Dec. 26 (Xinhua) -- China officially started construction of a Five-hundred-meter Aperture Spherical Telescope (FAST), the largest in the world, in a remote southwest region on Friday.
Preparation and research for the project took some 14 years.

The dish-like telescope, as large as 30 football fields, will stand in a region of typical Karst depressions in Guizhou Province when it's done in 2013.

Karst depressions are usually located in regions plentiful in limestone and dolomite, where groundwater has enlarged openings to form a subsurface drainage system.

The facility will greatly improve China's capacity for astronomical observation, according to the National Astronomical Observatory (NAO), the major developer of the program.

FAST's main spherical reflector will be composed of 4,600 panels. Its observation sensitivity will be 10 times more powerful than the 100-m aperture steerable radio telescope in Germany. Its overall capacity will be 10 times larger than what is now the world's largest (300 m) Arecibo radio telescope developed by the United States, according to Nan Rendong, the chief scientist of the project and an NAO researcher.

The project, costing more than 700 million yuan (102.3 million U.S. dollars), will allow international astronomers and scientists to discover more of the secrets of the universe based on cutting-edge technologies, said Zhang Haiyan, an NAO official in charge of construction.

Scientists have so far observed only 1,760 pulsars, which are strongly magnetized spinning cores of dead stars. With the help of FAST, they could find as many as 7,000 to 10,000 within a year, Nan said.

Pulsars have allowed scientists to make several major discoveries, such as confirmation of the existence of gravitational radiation as predicted by the theory of general relativity.

FAST could also be a highly sensitive passive radar to monitor satellites and space debris, which would be greatly helpful for China's ambitious space program.

The telescope could also help to look for other civilizations by detecting and studying communication signals in the universe.

Chinese scientists and officials selected Dawodang, Pingtang County as the site, where a Karst valley will match the shape of the huge bowl-like astronomical instrument.

The sparsely populated, underdeveloped region will provide a quiet environment to ensure the electromagnetic waves, the crucial requirement of operation, are not interrupted by human activities.

Construction of a new residential area about 60 km away also began on Friday to relocate 12 households. By 2013, when the telescope is to be in operation, all 61 farmers will move to their new houses in Kedu town, with farmland allocated by the government.

"The project is beyond my imagination. I'm glad to see that an ordinary old guy like me could contribute to the country's science program," said Yang Chaoli, 68.

The project was approved by the National Development and Reform Commission, the country's top planning body, the Ministry of Science and Technology, the Chinese Academy of Sciences and its subordinating NAO, Guizhou Province and other departments.

Link: Article

19 December 2008

In Remembrance: Steven Ostro

In Remembrance: Steven J. Ostro, radar astronomer at the Jet Propulsion Laboratory.

Link: Article - Sky and Telescope

Link: Planetary Society

Link: Blog Entry from Steve's brother (Stu Ostro)

10 December 2008

New Report: "Meteorites Hitting Early Earth's Oceans May Have Helped Spawn Life"

From the articles...

Many theories about the origins of life on Earth posit that prebiotic compounds may have arrived from outer space on asteroids or comets. But a new study suggests that extreme chemical reactions fired up by meteorite impacts may have jump-started life in the early oceans, rather than delivering its building blocks preformed. Meteorites striking the primordial oceans, the paper's authors say, could have supplied significant amounts of carbon, critical to life, and created a sort of chemical pressure cooker by the force of their impacts to synthesize the foundations of biological molecules.

The researchers report in Nature Geoscience today that they replicated the impact of a chondrite, a common type of meteorite, striking the ocean at about 1.25 miles (two kilometers) per second. The team did this by subjecting chemical constituents of chondrites (iron, nickel and carbon), as well as water and nitrogen, believed to be plentiful in the early atmosphere, to shock compression. The resulting pressures and temperatures, which likely exceeded 5,000 degrees Fahrenheit (2,760 degrees Celsius), yielded a variety of organic (carbon-based) compounds, such as fatty acids and amines. And when ammonia, which a previous study showed impacts could produce, was added to the starting mix, the experiment also yielded glycine (a simple amino acid).

Study co-author Toshimori Sekine, a researcher at the National Institute for Materials Science in Tsukuba, Japan, says he was surprised by the output from the experiment, adding that "there are many additional molecules we found but didn't analyze yet." Lead author Yoshihiro Furukawa, a PhD candidate at Tohoku University in Sendai, Japan, says that in light of the results, "we can say those ocean impact events [were] very effective processes for the production of various biomolecules on the early Earth." He is quick to note, though, that it is unclear how much or how many of these biomolecules would be needed to initiate life.

Link: Article: "Meteorites laid groundwork for early life"

Link: Article: Rock and Roil: Meteorites Hitting Early Earth's Oceans May Have Helped Spawn Life

02 December 2008

NYTimes Article on Early Earth

An interesting New York Times article on new evidence for a more benign early Earth has some information on early Earth bombardment. I would recommend the entire article but here is a section on early impact events...

Earth, like the other planets, coalesced more than 4.5 billion years ago. It is commonly hypothesized that almost immediately, a Mars-size object about 4,000 miles wide hit it — a true cataclysm that vaporized much of the object and Earth. Some of the debris ejected into orbit became the Moon. The molten Earth cooled quickly, probably within a few million years, and nothing that large ever struck again.

Dr. Sleep [Norman H. Sleep, professor of geophysics at Stanford] said his calculations suggested that during the 700 million years of the Hadean period about 15 objects 100 miles wide or wider hit the Earth. About four of the objects were wider than 200 miles, and those collisions would have been violent enough to boil off most of the oceans. (By contrast, the more recent object that hit the Earth 65 million years ago and helped kill off the dinosaurs was about 6 miles wide.)

But in numerical simulations that will be presented this month at a meeting of the American Geophysical Union in San Francisco, Dr. Mojzsis and Oleg Abramov, a postdoctoral researcher at the University of Colorado, show that the Late Heavy Bombardment impacts were not quite as lethal as had been thought.

“Things are hurt really bad,” Dr. Mojzsis said. But the computer calculations indicated that even rocks up to 300 miles wide would not kill everything, that pockets would exist where organisms that thrive in high-temperature environments like hydrothermal vents could survive.

Genetic studies of current life support that notion, pointing to an organism that lived in a high-temperature environment as the last common ancestor. That does not mean that life started there, but that is almost certainly where survivors of the giant impacts would have huddled.

Link: NYTimes Article: A New Picture of the Early Earth

01 December 2008

Article on Asteroid Threat and Initiatives Through U.N.

Former NASA Apollo astronaut, Russell Schweickart, is leader of an international Panel on Asteroid Threat Mitigation. Their report -- Asteroid Threats: A Call for Global Response -- is being briefed to United Nations officials, as well as leaders of space agencies around the world.

From the article...

A milestone-making report on the need to develop an international decision-making program to respond to the threat of Near Earth Objects (NEOs) has been briefed to United Nations officials in Vienna, Austria.

The report -- Asteroid Threats: A Call for Global Response -- was compiled by the international Panel on Asteroid Threat Mitigation, a group comprised of members of the Association of Space Explorers (ASE), as well as other experts tackling the NEO threat and repercussions to the Earth.

Former NASA Apollo astronaut, Russell Schweickart, is chairman of the panel and led the November 25 consultation with UN officials.

The briefing on the ASE-NEO report, its findings and implications, was given to a group of national representatives from the Permanent Missions to the United Nations in Vienna, in cooperation with One Earth Future Foundation.

The session was opened by Austrian Ambassador Helmut Böck who, along with Ciro A. Arévalo Yepes, the Chairman of the UN Committee on the Peaceful Uses of Outer Space (COPUOS), and Mazlan Othman, Head of the United Nations Office for Outer Space Affairs (UN-OOSA) sponsored the briefing.

The report is being submitted for consideration and subsequent action by the United Nations, with the goal to assist the international community in preventing loss of life and property resulting from an asteroid impact on Earth.

As the report underscores, there is need for a world-wide response to NEOs and the implications for Earth.

“Faced with such a threat, we are far from helpless. Astronomers today can detect a high proportion of Near Earth Objects and predict potential collisions with the Earth. Evacuation and mitigation plans can be prepared to cope with an unavoidable impact,” the report explains.

“For the first time in our planet's 4.5-billion-year history, the technical capacities exist to prevent such cosmic collisions with Earth. The keys to a successful outcome in all cases are preparation, planning, and timely decision-making,” the report states.

The Secure World Foundation (SWF) has a working relationship with the Association of Space Explorers and the Schweickart-chaired ASE Panel on Asteroid Threat Mitigation.

“We share a common interest in NEO governance. We also want to promote the results of their two-year process that has led to the report being submitted for consideration and subsequent action by the United Nations,” explained Cynda Collins Arsenault, President of the Secure World Foundation.

“These briefings are very important in terms of the UN receiving our report. There is only one institution in the world that represents everybody,” Schweickart said. To prevent an actual impact, he added, an international decision-making program, including necessary institutional requirements, must be agreed upon and implemented within the framework of the United Nations.

Schweickart also noted that briefings on the ASE-NEO report have been given to officials of several space agencies: The Indian Space Research Organization, the Canadian Space Agency, as well as NASA. Future briefings are being negotiated with the European Space Agency, China, Japan and Russia, he said.

At the close of the UN briefing in Vienna, former Austrian Ambassador Walther Lichem -- a member of the ASE International Panel on Asteroid Threat Mitigation -- made closing comments on the need for the UN “system” to deal seriously with the need for building the institutional capability to support the decision-making process ultimately required.

Link: Article

Podcast: Radio Astrobiology: Marco Polo and Meteorites

From the article...

Astrobiology Magazine presents a new podcast with our host Simon Mitton. In this interview, Beda Hofmann, an astrobiologist at the Natural History Museum in Bern, Switzerland, explores the links between meteorites, asteroids, and astrobiology. Europe's proposed Marco Polo Mission would land on an asteroid, drill down for samples, and return them to Earth. As Hofmann explains, the samples will be older than any rocks on Earth, and may contain important clues on the formation of the solar system.

Link: Astrobiology Magazine Article

Link: Podcast (.mp3)
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