HAYABUSA 2 IS ABOUT TO LAUNCH
On 30 November, Hayabusa 2 will lift off from Japan’s Tanegashima Space Center on a 6-year round trip to asteroid 1999 JU3. If all goes as planned, it should bring home samples not just from the asteroid’s surface but also from beneath it, by blasting a crater and collecting ejecta.
ASTEROID IMPACT THREAT: EXPERTS REPORT ON EARLY-WARNING STRATEGIES
Leonard David, in Space News, November 20 (heavily edited)
The danger of an asteroid smacking into Earth is a clear and present hazard, underscored by the huge fireball and shattering explosion that occurred over Chelyabinsk, Russia, in February 2013. A dedicated United Nations Action Team 14 has been deliberating over the years regarding the gathering and analysis of near-Earth object (NEO) data to provide timely warnings to national authorities should a potentially hazardous NEO threaten Earth. That work, in part, has helped produce an International Asteroid Warning Network (IAWN).
A workshop hosted by the Secure World Foundation in September brought experts together to discuss the IAWN, which operates independently of the United Nations. “We made very good progress toward identifying the main issues involved with communicating with the media and public regarding warnings of possible NEO impacts and other related issues,” said workshop participant Sergio Camacho, who chairs the U.N. Action Team on NEOs — a group that was established in 2001.
Workshop participants agreed that honing NEO-speak communiqués for the public and politicians will not be a simple task. For example, How will different audiences around the world receive and respond to IAWN messages, given the range among them of cultural and political contexts, leadership changes and current events; and of definitions and translation issues as well as religious beliefs and world views? “Communicating about any future asteroid threat will not be easy,” said Michael Simpson, SWF’s Executive Director. “People will need messages they can act on,” he told Space.com, “and they will deserve to know the limitations on what modern science can predict.”
“It is not just about crafting the right message, but also about understanding the different audiences, how they respond to information and how this impacts decision making,” Laura Delgado López told Space.com.
It is of paramount importance that this communication take place as early as possible and through channels that will reach as many people as possible, José Luis Galache said. “There is no point to discovering an impending danger from an asteroid if it’s not then possible to warn those who will be affected by it. Effective communication of the NEO hazard or imminent threat by a particular asteroid is paramount and just as important as NEO discovery.”
To read the full report, “Workshop on Communicating about Asteroid Impact Warnings and Mitigation Plans,” go to: http://swfound.org/media/186555/iawn_communication_workshop_report.pdf
DATA SHOWS FREQUENCY OF SMALL ASTEROID IMPACTS
JPL Press Release, November 14 (heavily edited)
Data gathered by U.S. government sensors and released to NASA for use by the science community reveal that these small impact events are frequent and random. A map of these small impact events – known as fireballs or bolides – recently released by NASA shows the frequency and approximate energy released by bolide events detected from 1994 through 2013. It dwarfs a data-base of small impacts based on infra-sound detections released last fall, but it does not contain all fireballs – objects less than a meter in size – that impacted the Earth during this period.
Over this 20-year interval, U.S. Government assets recorded at least 556 bolide events of various energies. On this world map illustration, the size of the orange dots (daytime events) and blue dots (nighttime events) are proportional to the optical radiated energy of the impact event measured in billions of Joules (GJ) of energy. An approximate conversion between the measured optical radiant energy and the total impact energy can be made using an empirical relationship provided by Peter Brown and colleagues in 2002. For example the smallest dot on the map represents1 billion Joules (1 GJ) of optical radiant energy, or when expressed in terms of a total impact energy the equivalent of about 5 tons of TNT explosives. Likewise, the dots representing 100, 10,000 and 1,000,000 GJ of optical radiant energies correspond to impact energies of about 300 tons, 18,000 tons and one million tons of TNT explosives respectively.
The largest impact energy recorded during this 20-year interval was the recent daytime Chelyabinsk event (440,000 – 500,000 tons of TNT) recorded over central Russia on February 15, 2013. This small asteroid was about 20 meters in size before it hit the Earth. While that impact focused public attention on the potential hazards of NEO impacts with Earth, space scientists have long known that such events are just a part of Earth’s geologic history.
Every day, Earth is bombarded with more than 100 tons of dust and sand-sized particles from space. About once a year, an automobile-sized asteroid hits Earth’s atmosphere, creating a spectacular fireball (bolide) event as the friction of the Earth’s atmosphere causes them to disintegrate – sometimes explosively.
Studies of Earth’s history indicate that about once every 5,000 years or so on average an object the size of a football field hits Earth and causes significant damage. Once every few million years on average an object large enough to cause regional or global disaster impacts Earth. Impact craters on Earth, the Moon and other planetary bodies are evidence of these occurrences.
For a documented list of bolide events, see: http://neo.jpl.nasa.gov/fireball
WHY WERE NEAS ADDED TO THE NASA LUNAR SCIENCE INSTITITE?
Selected Q&A from interview with Yvonne Pendleton (SSERVI Director)
Space News, November 24
Why was SSERVI formed?
The institute was created because complex science and engineering challenges require expertise and resources across many disciplines. By eliminating geographical constraints, the virtual institute model enables us to select the best investigations, teams and resources to address NASA’s current goals, regardless of where team members or infrastructure are located.
What do you focus on?
We tried to come up with questions we would need to answer before people travel beyond low Earth orbit. The topics include things like trying to understand how small bodies would outgas material. If you were approaching one, you would need to understand that. From a science perspective, volatiles are incredibly interesting to people who want to understand the origin, evolution and composition of these bodies.
What has SSERVI accomplished?
We picked teams in November. I got the teams together in December and asked them to come up with ideas for collaboration. They formed a long list and they’ve been marching right down that list. One was the idea of having a shared repository of samples that team members collect. If they go into the field to collect meteorites or rock samples that other teams want to analyze, they work from the same rock. They also share facilities, laboratory resources and students. Some teams are taking other teams’ students with them on trips to analog work sites. The teams are already publishing papers together.
Why is SSERVI at NASA Ames?
Ames is home to all of NASA’s virtual institutes: the NASA Astrobiology Institute, the NASA Aeronautics Research Institute and SSERVI (replacing NLSI). Ames is an innovative center. People here are very interested in cost-savings approaches to exploration. I think the institutes are thriving because we are in the heart of Silicon Valley. We pick up a lot of virtual tools hot off the press and introduce them to our community.
David Morrisons NEO News (now in its nineteenth year of distribution) is an informal compilation of news and opinion dealing with Near Earth Objects (NEOs) and their impacts. These opinions are the responsibility of the individual authors and do not represent the positions of NASA, Ames Research Center, the International Astronomical Union, NEOShield, or any other organization. If anyone wishes to copy or redistribute original material from these notes, fully or in part, please include this disclaimer.