Astronomer urges world to prepare for asteroids to hit earthBy John HollenhorstSALT LAKE CITY — Threats from the skies are real, and they could could push the human race to extinction, according to a prominent astronomer who spoke Friday in Logan. But he's quick to denounce a popular "end of the world" notion making the rounds this year.
Space is fairly dangerous. I like to say that the universe is trying to kill us.
–Phil PlaitHe worries about real threats to Earth, verified by science. There's not much we can do about extremely improbable threats like black holes, exploding stars and gamma-ray bursts, Plait said. But the most likely threat is from asteroids, which most scientists now accept as the instrument of doom for the dinosaurs. Every shooting star is a warning sign."Asteroid impacts are rare; they don't happen that much," Plait said. "But we just had something about the size of an SUV explode over California."If we sit around and do nothing long enough, a big asteroid hit is almost certain, Plait said, so let's do something."We have to find these asteroids," he said. "We have to find out, if we see one, how do we do this? Do we blow it up? Do we slam it? Do we tow it?"But the key, he said, is using science as a tool, instead of ignorance and phony mythology."It's so easy to fool human beings," he said. "And science circumvents that as long as you use it correctly."SOURCE: KSL.COM__________________________________________________________Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown@nasa.gov
Nancy Neal Jones
Goddard Space Flight Center, Greenbelt, Md.
301-286-0039
nancy.n.jones@nasa.gov April 18, 2012RELEASE : 12-121NASA Mission Wants Amateur Astronomers to Target AsteroidsWASHINGTON -- A new NASA outreach project will enlist the help of amateur astronomers to discover near-Earth objects (NEOs) and study their characteristics. NEOs are asteroids with orbits that occasionally bring them close to the Earth.
Starting today, a new citizen science project called "Target Asteroids!" will support NASA's Origins Spectral Interpretation Resource Identification Security - Regolith Explorer (OSIRIS-REx) mission objectives to improve basic scientific understanding of NEOs. OSIRIS-REx is scheduled for launch in 2016 and will study material from an asteroid.
Amateur astronomers will help better characterize the population of NEOs, including their position, motion, rotation and changes in the intensity of light they emit. Professional astronomers will use this information to refine theoretical models of asteroids, improving their understanding about asteroids similar to the one OSIRIS-Rex will encounter in 2019, designated 1999 RQ36.
OSIRIS-REx will map the asteroid's global properties, measure non-gravitational forces and provide observations that can be compared with data obtained by telescope observations from Earth. In 2023, OSIRIS-REx will return back to Earth at least 2.11 ounces (60 grams) of surface material from the asteroid.
Target Asteroids! data will be useful for comparisons with actual mission data. The project team plans to expand participants in 2014 to students and teachers.
"Although few amateur astronomers have the capability to observe 1999 RQ36 itself, they do have the capability to observe other targets," said Jason Dworkin, OSIRIS-REx project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.
Previous observations indicate 1999 RQ36 is made of primitive materials. OSIRIS-REx will supply a wealth of information about the asteroid's composition and structure. Data also will provide new insights into the nature of the early solar system and its evolution, orbits of NEOs and their impact risks, and the building blocks that led to life on Earth.
Amateur astronomers long have provided NEO tracking observations in support of NASA's NEO Observation Program. A better understanding of NEOs is a critically important precursor in the selection and targeting of future asteroid missions.
"For well over 10 years, amateurs have been important contributors in the refinement of orbits for newly discovered near-Earth objects," said Edward Beshore, deputy principal investigator for the OSIRIS-REx mission at the University of Arizona in Tucson.
NASA's Goddard Space Flight Center in Greenbelt, Md., will provide overall mission management, systems engineering and safety and mission assurance for OSIRIS-REx. Dante Lauretta is the mission's principal investigator at the University of Arizona. Lockheed Martin Space Systems in Denver will build the spacecraft. OSIRIS-REx is the third mission in NASA's New Frontiers Program. NASA's Marshall Space Flight Center in Huntsville, Ala., manages New Frontiers for the agency's Science Mission Directorate in Washington.
For more information about NASA, visit:
http://www.nasa.gov
For more information on Target Asteroids! and OSIRIS-REx, visit:
http://osiris-rex.lpl.arizona.edu- end -
SOURCE: NASA
Tucson scientist reveals new dangers of asteroid impact
Posted: Nov 5, 2010 6:00 AMTUCSON - New research by a Tucson scientist reveals shocking details about asteroids and our planet. The study shows certain asteroids could be more destructive than we ever thought.Elisabetta Pierazzo, a senior scientist at the Planetary Science Institute, studied asteroids ranging from 500 meters to one kilometer. Unlike the one that killed the dinosaurs, these asteroids would not cause mass extinction.
Impact of large asteroid may cause disruption of Earth ozonosphere
Is this all we can expect from such a catastrophic scenario? Or do we need to prepare for something more? As studies by the American scientists of the Planetary Science Institute (PSI) have shown, one more biosphere-destroying event will be the destruction of the planet’s ozone layer. The group, under the direction of Elizabeth Pierazzo, generated two models describing the fall of asteroids 500 and 1000 meters in diameter into the ocean (depth of 4000 meters). From their analysis of the data the scientists came to some conclusions about the catastrophic consequences of the ejection of huge quantities of hot water vapor into the atmosphere. After the water vapor, the liberation of huge volumes of chlorides and bromides will continue the process of destroying the ozone layer. As a result of these events, there will be a global exhaustion of the ozone layer, and Earth life will be defenseless for years.
The UVI (ultraviolet index) may be over 20 for several months after Earth is hit by a 500 meter asteroid. A reading of 10 is dangerous to humans, and 20 is the maximum value ever recorded on Earth. Under such radiation, a person can get burned even after only five minutes in the sun. Even more serious are the facts associated with the impact of a kilometer-sized asteroid. The brightness of the ultraviolet radiation will reach a huge value – 56! A person without protection in the open sunlight would literally burn up. The ultraviolet intensity would gradually decrease, but over the course of two years its level would remain over 20.
During this time most of the plant and animal life on Earth would perish; in countries where there are not huge reserves of foodstuffs, hunger would become a problem. All this is without calculating in the catastrophe which a huge tsunami would cause.
All these data are not to scare the people of the Earth, but, instead, they have the purpose of bringing understanding of what we must be prepared for, if we want to preserve our civilization at our modern level of development, and not plunge it into chaos because we couldn’t take a hit from space.
SOURCE: SPACE OBS.ORG LEONID ELENIN
New observations of Apophis
With these observations begins a new round of study of this interesting and potentially hazardous object. Remember that April 13, 2029 it passes closer to the Earth than geostationary satellites, at an elevation of about 30,000 km, and will be visible to the unaided eye. This passage will not be dangerous for our planet. The danger may be in the asteroid flying through the so called “keyhole” – a zone of width of only 600 km. If that happens, the Earth’s own gravitational influence will bring the asteroid into an orbit of resonant return, and in 2036 the asteroid will collide with the Earth. The probabilty of such an event is very small, but it does exist. The fall of a body with a diameter on the order of 270 meters can have catastrophic consequences for the Earth. We still have time and we must protect ourselves regardless of how events might develop. But we must do this before the 2029 passage, otherwise the complexity of this already difficult task will increase many times.
SOURCE: SPACE OBS.ORG LEONID ELENIN
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