The work goes on to see what is out there that might find its way here and make for a big boom. What we do with the information remains to be seen. It often comes down to money that has to be shared among a lot of mission requests.
It might be said that the squeaky wheel gets the grease, but sometimes when no grease is available the wheel may catch fire or just seize up, break, and fall off. Your interpretation of the sound bites may vary. :-)
- LRK -
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Ten Thousandth Near-Earth Object Discovered
"Finding 10,000 near-Earth objects is a significant milestone," said Lindley Johnson, program executive for NASA's Near-Earth Object Observations (NEOO) Program at NASA Headquarters. "But there are at least 10 times that many more to be found before we can be assured we will have found any and all that could impact and do significant harm to the citizens of Earth."
Near-Earth objects (NEOs) are asteroids and comets that can approach the Earth's orbital distance to within about 28 million miles (45 million kilometers). They range in size from as small as a few feet to as large as 25 miles (41 kilometers) for the largest near-Earth asteroid, 1036 Ganymed. Ninety-eight percent of all known near-Earth objects were first detected by NASA-supported surveys:statistics
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You may view charts and visuals of the numbers here.
- LRK -
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NEO Discovery Statistics
Some entries in the following charts and tables are dependent upon a diameter that is roughly inferred from the object’s estimated absolute magnitude (H) and its assumed reflectivity, or albedo. The absolute magnitude (H) of a near-Earth asteroid (NEA) is a measure of the object's brightness one astronomical unit from the sun and Earth and at zero phase angle (i.e., the angle between the sun and Earth, as seen from the NEA, is zero). The absolute magnitude (H) for a particular NEA is computed from the observed apparent magnitudes of the object at various times when the phase angles and the distances from the sun and Earth are known. An effective diameter is the diameter of a hypothetical spherical NEA that would provide the same apparent brightness as the observed NEA, whose actual shape is unknown.
Since most NEAs do not have a known reflectivity, or albedo, this albedo must be estimated before the H values, representing intrinsic brightness, can be converted to an approximate diameter. Pravec et al (2012) determined that, for their sample of 583 main-belt asteroids and NEAs, the mean albedos and their standard deviations are 0.057 (±0.013) for the Tholen/Bus/DeMeo C/G/B/F/P/D types and 0.197 (±0.051) for the S/A/L types. Since the albedos for NEAs are most likely to be either approximately 6% for asteroids of the C-type and associated taxonomic classes or 20% for asteroids of the more populous S-type and associated taxonomic classes, we have used an approximate mean value of 14% albedo and an H value of 17.75 to represent a one kilometer spherical NEA. Since the determined H values are uncertain, and likely biased by a few tenths (see Pravec et al., 2012, Icarus) and the single 14% albedo is only a rough mean representing a bimodal albedo distribution, the estimated numbers of one kilometer and larger sized objects in the tables below are very rough. However, these statistics are useful for monitoring the annual NEA discovery progress.
Using near-infrared data provided by the WISE spacecraft in 2010 and early 2011, Mainzer et al (2011) were able to determine diameters and albedos for 250 NEAs with a minimum uncertainty of 10% and 20% respectively. Hence they were able to determine the albedo distribution of these objects with known diameters and this distribution was then used to compute diameters for previously known NEOs with known H values but unknown diameters or albedos. They provided an estimate of 981 (±19) NEAs as the total population of NEAs one kilometer and larger. At the time of their analysis (Spring 2011), they also estimated that 911 (±17) of these large NEAs had already been discovered. While this latter estimate is both higher and more accurate than the estimated numbers given for Spring 2011 in the following tables, this statistical technique cannot be easily employed for day-to-day estimates of the population of NEAs one kilometer and larger. In the following tables, we will continue to use the simpler method described in the previous paragraph.
Since most NEAs do not have a known reflectivity, or albedo, this albedo must be estimated before the H values, representing intrinsic brightness, can be converted to an approximate diameter. Pravec et al (2012) determined that, for their sample of 583 main-belt asteroids and NEAs, the mean albedos and their standard deviations are 0.057 (±0.013) for the Tholen/Bus/DeMeo C/G/B/F/P/D types and 0.197 (±0.051) for the S/A/L types. Since the albedos for NEAs are most likely to be either approximately 6% for asteroids of the C-type and associated taxonomic classes or 20% for asteroids of the more populous S-type and associated taxonomic classes, we have used an approximate mean value of 14% albedo and an H value of 17.75 to represent a one kilometer spherical NEA. Since the determined H values are uncertain, and likely biased by a few tenths (see Pravec et al., 2012, Icarus) and the single 14% albedo is only a rough mean representing a bimodal albedo distribution, the estimated numbers of one kilometer and larger sized objects in the tables below are very rough. However, these statistics are useful for monitoring the annual NEA discovery progress.
Using near-infrared data provided by the WISE spacecraft in 2010 and early 2011, Mainzer et al (2011) were able to determine diameters and albedos for 250 NEAs with a minimum uncertainty of 10% and 20% respectively. Hence they were able to determine the albedo distribution of these objects with known diameters and this distribution was then used to compute diameters for previously known NEOs with known H values but unknown diameters or albedos. They provided an estimate of 981 (±19) NEAs as the total population of NEAs one kilometer and larger. At the time of their analysis (Spring 2011), they also estimated that 911 (±17) of these large NEAs had already been discovered. While this latter estimate is both higher and more accurate than the estimated numbers given for Spring 2011 in the following tables, this statistical technique cannot be easily employed for day-to-day estimates of the population of NEAs one kilometer and larger. In the following tables, we will continue to use the simpler method described in the previous paragraph.
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"Grand Challenges," let me clear my throat, ach, hmm, for whom?
- LRK -
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White House, NASA want help hunting asteroids
June 22, 2013By Joel AchenbachThe Washington Post
WASHINGTON — The White House and NASA on Tuesday will ask the public for help finding asteroids that potentially could slam into the Earth with catastrophic consequences.
Citing planetary defense, the administration has decided that the search for killer rocks in space should be the latest in a series of "Grand Challenges," in which the government sets an ambitious goal, helps create public-private partnerships and sometimes offers prize money for innovative ideas.
"This is really a call to action to find all asteroid threats to human populations and know what to do about them," NASA Deputy Administrator Lori Garver said Monday. She said the asteroid hunt would help prove that "we're smarter than the dinosaurs."
- See more at: http://randolphguide.com/
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Finding what is out there is important if you want to go catch an asteroid or push one around. How you define a set of missions will have to take into account risk and cost, and just what are the benefits. We seem to do a lot of talking.and I don't know that the asteroids are listening. :-)
- LRK -
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House Hearing Shows Opposition to Asteroid Mission, Divisions on Draft Bill
Marcia S. Smith
Posted: 19-Jun-2013
Updated: 20-Jun-2013 12:46 AM
Updated: 20-Jun-2013 12:46 AM
The House subcommittee hearing on a draft 2013 NASA Authorization Act this morning showed continued skepticism about or opposition to the Obama Administration's proposed asteroid initiative. It also revealed that even some Republicans on the subcommittee object to certain provisions of the draft bill.
Rep. Steve Palazzo (R-MS), chairman of the Space Subcommittee of the House Science, Space and Technology Committee, began the hearing by praising the committee's outreach efforts in drafting the bill saying that it was the result of "input from a wide variety of interests throughout the science and space communities." Somewhat surprisingly then, not only did subcommittee Democrats and both witnesses -- NASA Advisory Council Chairman Steve Squyres and retired industry executive Tom Young -- express deep reservations about the bill, but the subcommittee's vice chairman, Rep. Mo Brooks (R-AL), said he "may have to oppose it."
Brooks's complaint is the $1.4 billion for the Space Launch System (SLS) included in the bill is insufficient. He read from an email sent by former NASA Administrator Mike Griffin and a letter from an unnamed former NASA official both insisting that a minimum of $1.8 billion is needed for that program. SLS is being built at Marshall Space Flight Center, which Brooks represents.
The total amount of funding provided by the bill is $16.845 billion for FY2014 and for FY2015. A provision in the bill says that if Congress repeals or replaces the sequester and additional funds become available, they are to be spent 50 percent for the International Space Station (ISS), 25 percent for commercial crew, and 25 percent for SLS.
Not everyone on the committee is a fan of SLS, however. Rep. Dana Rohrabacher (R-CA), vice chairman of the full committee and a strong supporter of commercial space, called it the "SLS Titanic," saying it is not sustainable and will drain money from everything else. He asked Squyres, who is best known as the principal investigator for the Mars rovers Spirit and Opportunity, if SLS is a prerequisite for sending people to Mars. Squyres said that some sort of heavy lift rocket is needed, but his main concern is that NASA is being asked to do too much with too little: "We can afford to utilize the space station.... We can afford to develop SLS and to do it on a safe and reasonable schedule. But I don't see that we can do both." Squyres also expressed concern about the low launch rate expected for SLS -- perhaps one launch every two years -- an issue he has emphasized in the past.
Later, Rep. Bill Posey (R-FL) asked Squyres and Young when we could send people to Mars if we started right now. Squyres asked "with the current budget?" and then turned to Young, who quickly responded "never." Squyres added "I agree."
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And the hands are raised and you hear the shouts, "Fund me, fund me!"
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How Can We Defend Earth From Asteroids?
"When I go outside and it's clear? Yeah, I look up. It's a habit. It's something I wish more people did. You may seem something that will profoundly affect you."— Phil Plait
Gazing up at the night sky is simultaneously humbling and utterly thrilling. This hour, we'll hear from TED speakers who share an infectious sense of wonder and curiosity about our place in the universe and what lies beyond our skies.
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Thanks for looking up with me.
- LRK -
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- LRK -
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WHAT THE MIND CAN CONCEIVE, AND BELIEVE, IT WILL ACHIEVE - LRK -
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