Archive for the ‘Near Earth Object’ Category
Asteroids and Black Holes | SciByte 20
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We take a look at asteroid flyby’s, black hole data, new elements, Mars water, the brain, headaches, Mars500, health sensors in our cars and game systems, and take another peek at what’s up in the sky this week.
SciByte will provide you with a treasure trove of small talk for your next cocktail party, the knowledge to show off to friends and family, and provide you the means, with the help of our trusty show notes, to further investigate the things that interest you the most.
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Nov. 8 Asteroid Flyby

- The low down
- 2005 YU55 : 1,300-foot-wide (quarter-mile / 400-meter) asteroid
- At the point of closest approach, it will be no closer than 201,700 miles (324,600 kilometers) or 0.85 the distance from the moon to Earth. (above the Guatemalan coast)
- Data collected during Arecibo’s observation of 2005 YU55 allowed scientists to refine the space rock’s orbit, allowing the Near-Earth Object Program Office at NASA’s Jet Propulsion Laboratory to rule out any possibility of an Earth impact for the next 100 years.
- Amateur astronomers would need a 6-inch-or-bigger telescope and know exactly where to look to spot it.
- Significance
- The gravitational influence of the asteroid will have no detectable effect on anything here on Earth, including our planet’s tides or tectonic plates.
- NASA scientists hope to obtain images of the asteroid from Goldstone as fine as about 7 feet (2 meters) per pixel.
- The last time a space rock as big came as close to Earth was in 1976, although astronomers did not know about the flyby at the time. The next known approach of an asteroid this large will be in 2028.
- With more observations in the coming years, scientists may be able to accurately plot 2005 YU55’s orbit even further out.
- * Of Note*
- If it’s so close why can’t we spot it naked eye? One, it’s a dark object, composed of carbonaceous material and is thus effectively darker than coal. Two, the moon is close to full.
- As for an actual strike by an asteroid this size, that’s estimated to occur once every 100,000 years or so.
- If 2005 YU55 were to plow into the home planet, it would blast out a crater four miles across and 1,700 feet deep, according to Melosh’s calculations. Think a magnitude–7 earthquake and 70-foot-high tsunami waves
- Multimedia
- Huge Space Rock 2005 YU55 Sneaks Within Moon’s Distance (Infographic) @ Space.com
- VIDEO : Asteroid 2005 YU55 @ YouTube.com
- Close Shave Asteroid 2005 YU55 Bombarded by Radio Waves
- VIDEO : Radar image of 2005 YU55, acquired in April 2010
- VIDEO : First Movie of Asteroid 2005 YU55
- 2005YU555 Fly-by in Spacemap
- Animation of the trajectory for asteroid 2005 YU55 – November 8–9, 2011. Image credit: NASA/JPL-Caltech
- Social Media
- On Twitter, Asteroid YU55 @AsteroidYU55
- @NASAJPL :: Asteroid 2005 #YU55 comes closest to Earth at 3:28pm PT, ~200,000 miles above the Guatemalan coast. Map
- On Twitter, Asteroid Watch @AsteroidWatch
- Further Reading / In the News
- NASA in Final Preparations for Nov. 8 Asteroid Flyby @ NASA.gov
- Asteroid 2005 YU55: An Expert’s Explanation @ UniverseToday.com
- Radar Love: Asteroid Detection and Science @JPL.NASA.gov
- Radar Clicks Asteroid’s Pic @ JPL.NASA.gov
- Quarter-mile-wide asteroid coming close to Earth @ Physorg.com
- New Model Predicts Fallout from Big Meteorite Strike @ LiveScience.com
- How to Spot the Huge Asteroid 2005 YU55’s Close Encounter With Earth @ Space.com
- Asteroid 2005 YU55: See It For Yourself! @ UniverseToday
- Huge Asteroid 2005 YU55 Approaches Earth @ Discovery.com
- 2005 YU55 asteroid will sweep near Earth November 8, 2011 @ EarthSky.org
- Asteroids: Formation, Discovery and Exploration @ Space.com
- Huge Asteroid 2005 YU55 Zips by Earth in Rare Close Flyby @Space.com
- Slooh SpaceCamera
- More information about asteroids and near-Earth objects
- More information about asteroid radar research is at
- More information about the Deep Space Network is at
Direct Observations of disk around black hole

- The low down
- Quasars — short for quasi-stellar objects — are glowing discs of matter that orbit supermassive black holes, heating up and emitting extremely bright radiation as they do so.
- Until now, the minute apparent size of quasars has meant that most of our knowledge of their inner structure has been based on theoretical extrapolations, rather than direct observations.
- The new study makes use of a novel technique that uses gravitational lensing to give an immense boost to the power of the telescope.
- The team measured the disc’s size and studied the colours (and hence the temperatures) of different parts of the disc.
- The team used an innovative method to study the quasar: using the stars in an intervening galaxy as a scanning microscope to probe features in the quasar’s disc that would otherwise be far too small to see.
- Significance
- this type of observation is akin to spotting individual grains of sand on the Moon
- The precision of the method has allowed astronomers to directly measure the disc’s size and temperature across different parts of the disc.
- They found that the disc is between four and eleven light-days across (approximately 100 to 300 billion kilometres).
- Multimedia
- VIDEO : Observing a quasar accretion disc using gravitational lensing with Hubble @ YouTube.com
- This picture shows a quasar that has been gravitationally lensed by a galaxy in the foreground, which can be seen as a faint shape around the two bright images of the quasar.
- Social Media
- On Twitter, Hubble @NASA_Hubble
- Further Reading / In the News
- Hubble directly observes the disc around a black hole @ SpaceTelescope.org
- Hubble Telescope Directly Observes Quasar Accretion Disc Surrounding Black Hole @ UniverseToday.com
- Hubble Directly Observes the Disk Around a Black Hole @ ScienceDaily.com
- Hubble directly observes the disc around a black hole [heic 1116] @ Sci.ESA.int
- Hubble directly observes the disk around a black hole @ Astronomy.com
*— NEWS BYTE — *
Three New Elements Added To The Periodic Table
- The low down
- November 4, 2011, the General Assembly of the International Union of Pure and Applied Physics (IUPAP) met to approve the names of three new elements… one of which will honor the great Copernicus
- Copernicus was a Renaissance astronomer and the first person to formulate a comprehensive heliocentric cosmology which displaced the Earth from the center of the universe.
- Their names are: Element 110, darmstadtium (Ds), Element111, roentgenium (Rg) and Element 112. copernicium (Cn).
- Copernicium was created on February 9, 1996 by the Gesellschaft für Schwerionenforschung, but its original name – ununbium – didn’t get changed until almost two years ago when a German team of scientists provided enough information to prove its existence.
- When it was time to give it a moniker, the rules were that it had to end in “ium” and it couldn’t be named for a living person.
- Multimedia
- Electron shell diagram for Copernicium
- Periodic Table of Elements
- Further Reading / In the News
- Honoring Copernicus – Three New Elements Added To The Periodic Table @UniverseToday.com
- Three new elements named, including one for Copernicus @ PhysOrg.com
- International Union of Pure and Applied Physics (IUPAP)
Mars’ history is a fluid situation
- The low down
- The picture painted by a review paper in the November 3 issue of Nature.
- An international team of researchers crafted a tale of Mars’ parched, frigid history
- Four billion years ago, the Martian surface may have been cold and dry — not warm, watery and more Earthlike than it is today, as many scientists have suggested.
- Instead of saturating the dusty surface, fluids appeared only occasionally, quickly shaping channels and other landforms that bear watery footprints.
- Beneath the planet’s reddish, rocky sands lurked a warm and wet subterranean environment, a potential incubator powered by hydrothermal activity and revealed when meteorite impacts blasted telltale minerals from the planet’s crust.
- Water-carved landscapes, like snaking channels and river deltas, played a large role in producing the current view of a warm and watery Martian past.
- Significance
- If the authors are right, scientists hunting for evidence of past Martian life might be better off using a shovel
- While the evidence for subterranean hydrothermal activity is strong, Bishop says it’s unlikely that transient or small amounts of surface water quickly crafted some of the river features, valley networks, or layered beds seen across Mars.
- In September, NASA announced that Opportunity had found a rock at the edge of Endeavour Crater that looked as though it had been formed in a subterranean hydrothermal system.
- Whether life might have evolved in the Martian subsurface is an open question. But on Earth, even multicellular organisms can live in the deep.
- Multimedia
- Mars WHERE’S WATER?
- Further Reading / In the News
- Mars’ history is a fluid situation @ ScienceNews.com
- ‘Tisdale 2’ Rock, Next Stop for Opportunity @ NASA.gov
Researchers identify brain cells responsible for keeping us awake
- The low down
- Bright light makes it easier to stay awake.
Very bright light not only arouses us but is known to have antidepressant effects - dark rooms can make us sleepy
- researchers at UCLA have identified the group of neurons that mediates whether light arouses us – or not
- the cells necessary for a light-induced arousal response are located in the hypothalamus, an area at the base of the brain responsible for, among other things, control of the autonomic nervous system, body temperature, hunger, thirst, fatigue – and sleep.
- These cells release a neurotransmitter called hypocretin
- Significance
- This same UCLA research group earlier determined that the loss of hypocretin was responsible for narcolepsy and the sleepiness associated with Parkinson’s disease
- This current finding explains prior work in humans that found that narcoleptics lack the arousing response to light, unlike other equally sleepy individuals
- findings suggest that administering hypocretin and boosting the function of hypocretin cells will increase the light-induced arousal response
- onversely, blocking their function by administering hypocretin receptor blockers will reduce this response and thereby induce sleep
- implications for treating sleep disorders as well as depression
- Further Reading / In the News
- UCLA researchers identify brain cells responsible for keeping us awake @ UCLA Newsroom
- Researchers identify brain cells responsible for keeping us awake @ MedicalxPress.com
- Researchers Identify Brain Cells Responsible for Keeping Us Awake @ BioScienceTechnology.com
- Brain Cells Responsible for Keeping Us Awake Identified @ TimesofScience.com
Headache tree is a pain in the brain

- The low down
- One whiff of bay laurel tree can spur intense, excruciating pain — and now scientists know why.
- An ingredient in the tree sets off a chain of events that eventually amps up blood flow to the brain’s outer membrane.
- The protein tickles the same cellular detector that responds to painfully cold stimuli and the sinus-clearing scent of wasabi and mustard oil
- This protein prompts blood vessels to swell, and scientists think this swelling puts pressure on the skull and nerves, causing pain.
- Significance
- Other headache triggers interact with some of the same cellular machinery, suggesting they all work via the same pain-inducing mechanism.
- Stimulating this chemical detector ultimately triggers the release of a particular protein implicated in migraine headaches
- Further Reading / In the News
- Headache tree is a pain in the brain @ ScienceNews.org
Mars500 experiment ends
- The low down
- All-male crew of three Russians, a Frenchman, an Italian-Colombian and a Chinese have stayed at the facility at a Moscow space research center since June 2010 to simulate confinement, stress and fatigue of interplanetary travel minus the weightlessness.
- the crew achieved the longest-ever imitation of space flight
- During the experiment, the crew communicated with the organizers and their families via the Internet, which was delayed and occasionally disrupted to imitate the effects of space travel.
- They ate canned food similar to that offered on the International Space Station.
- the crew even conducted a mock Mars landing, venturing from their cramped quarters in heavy space suits to trudge into a sand-covered room and plant flags of Russia, China and the European Space Agency on a simulated Red Planet.
- The organizers said each crew member will be paid about $100,000, except the Chinese researcher whose reward hasn’t been revealed by Chinese officials.
- The organizers said they had considered some female candidates for the experiment, but left them out for various reasons.
- They denied that they deliberately had formed an all-man crew because of the failure of a similar simulation in the past.
- To kill time, China’s Wang Yue practiced calligraphy, France’s Romain Charles strummed his guitar and together the crew, aged from 28–38, played karaoke, chess and Nintendo Wii.
- Significance
- Space veteran Sergei Krikalyov, who has spent a record 803 days in orbit, told Reuters: “It’s useful but, sitting here on Earth, it won’t solve real problems of long human exposure in space.”
- “The most difficult thing for them was being starved of information.”
- A previous 420-day experiment ended in drunken disaster in 2000, when two participants got into a fistfight and a third tried to forcibly kiss a female crew member.
- Multimedia
- Mars500 video diary 1 – Diego’s guided tour()
- Mars500 – 520 days in 15 minutes
- Replay of the Mars500 hatch opening
- Mars500: Photos From Russia’s Mock Mars Mission @ Space.com
- Replay of the Mars500 hatch opening @ YouTube.com
- Social Media
- Twitter account, Mars500 experiment @Mars_500
- Further Reading / In the News
- ESA Mars 500
- Hatch Opens as Simulated Mars Mission Ends @ UniverseToday.com
- Researchers complete 520-day mock mission to Mars @ PhysOrg.com
- Mars500 Crew Finally Freed @ PBS.org
- Fake Mars mission to open hatch after 520 days in isolation @ MotherNatureNetwork
- “Mars crew” played Counter-Strike to cool tempers @ Reuters
Health check on the road
- The low down
- A research team at the Technische Universitaet Muenchen (TUM), in collaboration with researchers at the BMW Group develop a sensor system integrated into the steering wheel that can monitor the driver’s state of health while driving
- monitors vital signs such as heart rate, skin conductance and oxygen saturation in the blood via simple sensors in the steering wheel
- A driver’s skin conductance, for instance, reveals whether he or she is under severe stress, or whether his or her blood pressure exceeds a critical value
- Two commercially available sensors are key elements of the integrated vital signs measurement system
- One of them shines infrared light into the fingers and measures the heart rate and oxygen saturation via reflected light
- One of them shines infrared light into the fingers and measures the heart rate and oxygen saturation via reflected light
- Significance
- the device might be used recognize the onset fainting spells or heart attacks
- When a stress situation is detected by means of skin conductance values, phone calls can be blocked, for instance, or the volume of the radio turned down automatically.
- With more serious problems the system could turn on the hazard warning lights, reduce the speed or even induce automated emergency braking
- Further Reading / In the News
- Health check on the road @ PhysOrg.com
- Health Check on the Road: Safe Stop When the Driver Can’t Go On @ ScienceNEwslineTechnology
Sony Patent Reveals Biometric Controllers
- The low down
- Measuring skin moisture, heart rhythm and muscle movement
- The last time biometric feedback was introduced to mainstream games was Nintendo’s vitality sensor, which was announced at E3 2009 but never released.
- Mentioned in the application
- Character changes based on biometric feedback, such as a character sweating when you’re nervous.
- Tensing up your muscles to absorb an attack or power up shields
- Weapons that become more accurate or less steady depending on your level of stress
- A boost to run faster, jump higher and punch harder while stressed
- Rapid decreases in health if your stress increases
- Different attacks based on stress levels.
- Background music that matches your stress level, or becomes more relaxing if you’re stressed
- Scaling difficulty based on stress level.
- Further Reading / In the News
- Sony Patent Reveals Biometric Controllers
Largest Sunspot in Years Observed on the Sun

- The low down
- The massive sunspot, called AR1339, is about 50,000 miles (80,000 km) long, and 25,000 miles (40,000 km) wide
- Earth itself is only 8,000 miles (12,800 km) wide.
- Was first observed Nov 3 by NASA’s Solar Dynamics Observatory (SDO) satellite and was not yet facing Earth
- Sunspots appear when intense magnetic activity ramps up on the sun, blocking the flow of heat through the process of convection, which causes areas of the sun’s surface to cool down.
- Sunspots appear when intense magnetic activity ramps up on the sun, blocking the flow of heat through the process of convection, which causes areas of the sun’s surface to cool down.
- The intense magnetic activity around sunspots can often cause solar flares, which are large releases of energy that can actually brighten up the sun.
- Significance
- Flares are also accompanied by flows of charged particles out into space, called coronal mass ejections, which can wreak havoc on satellites and power grids on Earth if they head our way.
- AR1339 erupted with an X-Class solar flare and a coronal mass ejection forecast to impact Mercury on November 4 and Venus on November 5
- The MESSENGER spacecraft currently orbiting Mercury is in prime condition to observe the CME scour material off the planet’s surface and form a temporary comet-like tail.
- Multimedia
- VIDEO : Solar Flare From Group AR1339 (2011.11.03) @YouTube
- Analysts at the Goddard Space Weather Lab
- The Sun as of 20:00 UT on Nov. 3, 2011. AR 1339 is on the top left of the Sun. Credit SDO/GSFC
- Social Media
- Twitter account for Space Weather @spaceweather
- Twitter account for NASA Goddard’s Space Weather Lab @NASA_SDO
- Twitter account for iNtegrated Space Weather Analysis System @NASAiSWA
- Further Reading / In the News
- Largest Sunspot in Years Observed on the Sun @Space.com
- Huge Sunspot (Named AR1339) @ AccuWeather.com
+Giant Sunspot Unleashes Massive Solar Flare @ Space.com - Largest Sunspot in Years Now on the Sun @ UniverseToday
+NOAA projects 20% chance of X-class solar flares today
LAUNCHING THIS WEEK
Phobos-Grunt and Yinghuo–1
- Launch Date
- November 9, 2011 at 00:26 a.m. Moscow time [Nov. 8 3:36 p.m. EST]
- Mission Duration
- 3 years
- Mission Run Down
- The Phobos-Grunt (A Russian spacecraft) mission will try to grab some Phobos (the larger of Mars’s two tiny moons) soil and bring it back to Earth
- Phobos-Grunt translates as Phobos-Soil.
- Phobos–Grunt is bringing a couple of tagalongs on the trip
- One is China’s first Mars craft, a small satellite called Yinghuo 1 that will orbit Mars
- The other is a project of the nonprofit Planetary Society: a biological experiment called Phobos LIFE
- Further Reading
- Phobos-Grunt and Yinghuo–1 Encapsulated for Voyage to Mars and Phobos
- Planetary Scientists Hope to Bring Back Mars Moondust @ ScientificAmerican
- China’s Yinghuo–1 Mars Orbiter
- LIFE Experiment: Shuttle & Phobos
- Multimedia
- Animated look at the Phobos-Grunt mission @ Space.com
SCIENCE CALENDER
Looking back this week
- Nov 11, 1572 – 439 years ago : Tycho’s Supernova – Danish astronomer Tycho Brahe began his meticulous observations of the supernova. Brahe was at the beginning of his career in 1572, and it was this supernova that inspired him to devote his lifetime to making accurate measurements of the positions of the stars and planets. Thus 16th-century astronomers learned that the heavens were not immutable, as had been believed. Brahe’s book on his observations, De Nova Stella, originated the word “nova.”
- Nov 14, 1666 – 345 years ago : First blood transfusion – the English physician, Samuel Pepys, made an record in his diary describing Richard Lower making the first documented blood transfusion.
- Nov 10, 1885 – 126 years ago : Motorcycle – the world’s first motorcycle, designed by Gottlieb Daimler, made its debut. The frame and wheels were made of wood. A leather belt transfered power from the engine to large brass gears mounted to the rear wheel. The single cylinder engine had a bore of 58mm and stroke of 100mm giving a displacement of 264cc’s. The engine gave 0.5hp at 700 rpm. The top speed for the motorcycle was 7mph [12 km/h]
- Nov 12, 1901 – 110 years ago : First Nobel Prize in Physics – The first Nobel Prize for Physics was awarded to Wilhelm Roentgen for his discovery of X-rays.
- Nov 11, 1925 – 86 years ago : Cosmic rays – the discovery of cosmic rays was announced in Madison, Wisconsin by Robert A. Millikan who coined their name.
- Nov 12–13, 1927 – 84 years ago : Holland Tunnel – the Holland Tunnel connecting N.Y. and N.J., the world’s first underwater vehicular tunnel, officially opened.
- Nov 13, 1946 – 65 years ago : Artificial snow – artificial snow from a natural cloud was produced over Mount Greylock, Mass., for the first time in the U.S. An airplane spread small pellets of dry-ice (frozen carbon dioxide) for three miles at a height of 14,000 ft. Although the snow fell an estimated 3,000 feet, it evaporated as it fell through dry air, and never reached the ground.
- Nov 09, 1957 – 54 years ago : Laser invented – Gordon Gould began to write down the principles of what he called a laser in his notebook during a sleepless Saturday night. By Wednesday morning he had a notary witness and date his notebook. Unfortunately, he misunderstood the patent process, and did not file promptly. But, other scientists, did file for a patent on their similar but independent discovery of how to make a laser. When Gould belatedly tried to get a patent, it took decades to eventually establish priority and gain what had then grown to be profitable royalties from the established laser industry.
- Nov 13, 1971 – 40 years ago : Mars satellite – Mariner–9, the first man-made object to orbit another planet, entered Martian orbit. The mission of the unmanned craft was to return photographs mapping 70% of the surface, and to study the planet’s thin atmosphere, clouds, and hazes, together with its surface chemistry and seasonal changes.
- Nov 10, 1983 – 28 years ago : First computer virus – U.S. student Fred Cohen presented to a security seminar the results of his test – the first documented virus, created as an experiment in computer security.In the paper, he defined a virus as “a program that can ‘infect’ other programs by modifying them to include a … version of itself”.
- Nov 09, 1991 – 20 years ago : Nuclear fusion power – In Culham, England, nuclear fusion was first harnessed to produce a significant amount of power. Though lasting for only two seconds, about 1.7 megawatts of electric power was produced.
Post Show Correction
- One letter can make a world of difference …
- Today’s power plants use fission to generate heat and do useful work. The creation of the first man-made fission reactor, known as Chicago Pile–1, achieved criticality on December 2, 1942. Fusion differs from the fission reactions used in current nuclear power plants for it occurs when light nuclei travelling at high speed combine, without radioactive waste as a byproduct.
Looking up this week
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You might have seen …
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Tuesday, Nov. 8 : The bright “star” near the Moon is Jupiter. Although they look close together, Jupiter is 1,400 times farther away.
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Tuesday, Nov. 8 : 2005 YU55 passed closer to us than the Moon; closest approach was at 6:28 p.m. EST. ’s visible across North America in the ensuing hours, dim at 11th or 12th magnitude and moving fast Chart
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Keep an eye out for …
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Wednesday, Nov. 9 : In bright twilight just 20 or 30 minutes after sunset, bring binoculars to a location with a clear view practically down to the southwest horizon. There will be Venus
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Thursday, Nov. 10 : Full Moon
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Thursday-Sunday Nov. 10–13 : Mars moves past Regulus, the brightest star of Leo, the lion. They rise shortly after midnight and are high in the southeast at first light. Mars looks like a bright orange star with Regulus quite close to the right or lower right.
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Friday, Nov. 11 : Venus and Mercury are quite lo
Near Earth Objects | SciByte 12
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This week on SciByte we take a look at Near Earth Object, what qualifies as a NEO, what dangers they actually pose and some of the impacts that had already occurred on the Earth. Plus we take a quick look at at the DAWN spacecraft that is currently orbiting the asteroid Vesta and has plans to visit the asteroid Ceres as well.
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Show Notes:
What is a Near Earth Object? NEO
- A Solar System object, like comets or asteroids, whose orbit brings them into close proximity, less than 1.3 AU, with the Earth.
- That’s 15,245.6 times the diameter of the Earth, or 508.2 times the distance from the center of the Earth to the center of the Moon.
- 1.3 AU =
120,842,549.5 mi / 194,477,231.9 km - Astronomical unit (AU) :
92,955,807.3 mi / 149,597,870.7 km - Earth’s Diameter :
7,926.4 mi / 12,756.3 km - Moon Orbit ~=
238,858.2 mi / 384,405 km - Moon Orbit ~=
30 Earth Diameters
- 1.3 AU =
Asteroids and Meteoroids and Meteorites … oh my!
- Asteroid : A relatively small, inactive, rocky body orbiting the Sun.
- Comet : A relatively small, at times active, object whose ices can vaporize in sunlight forming an atmosphere (coma) of dust and gas and, sometimes, a tail of dust and/or gas.
- Meteoroid : A small particle, conventionally below 32ft / 10m, from a comet or asteroid orbiting the Sun.
- Meteor : The light phenomena which results when a meteoroid enters the Earth’s atmosphere and vaporizes; a shooting star.
- Meteorite : A meteoroid that survives its passage through the Earth’s atmosphere and lands upon the Earth’s surface.
What was that thing I saw in the sky?
- It depends on when and what you saw …
- Meteors, often called shooting stars or fireballs, streak across the sky in a matter of seconds, can leave a faint ionization trail visible for minutes, and can be as bright as the Moon sometimes.
- Satellites in orbit around the Earth, are much slower moving and relatively constant in brightness. Just after sunset and before sunrise, are likely times to see them as this is the time when they are reflecting sunlight but it is still dark on the surface of the Earth. (Some satellites can flare up for a few seconds and become very bright when their solar panels reflect the sunlight.)
Asteroids / NEO’s Facts
- The mass of all the objects of the Main asteroid belt, lying between the orbits of Mars and Jupiter, is about 4 percent of the mass of the Moon.
- Objects spend on average a few million years as NEOs before hitting the Sun, being ejected from the Solar System, or (for a small number of them) hitting a planet.
How Many Near-Earth Objects Have Been Discovered So Far?
- August 8, 2011 : 8,168 Near-Earth objects have been discovered.
- 828 have a diameter of approximately 0.6mi / 1 km or larger
- 1,243 have been classified as Potentially Hazardous Asteroids (PHAs).
- NASA – How many NEO’s have been discovered?
*Generally the hype from an object is more due to the ‘late discovery’ of an object. With some being discovered mere days before an encounter.
Potentially hazardous object
- An asteroid or comet with an orbit such that it has the potential to make close approaches, within 0.05 AU, to the Earth and a size large enough to cause significant regional damage in the event of impact.
- That’s 586.4 times the diameter of the Earth, or 19.5 times the distance from the center of the Earth to the center of the Moon.
- Astronomical unit (AU) :
92,955,807.3 mi / 149,597,870.7 km - Earth’s Diameter :
7,926.4 mi / 12,756.3 km - Moon Orbit ~=
238,858.2 mi / 384,405 km</li>30 Earth Diameters
<li>Moon Orbit ~=
- Astronomical unit (AU) :
- Diameter is at least
492ft / 150 m.- Would cause regional devastation to human settlements. No impact of this size has occurred during human history.
- Such impacts would occur on average around once per 10,000 years.
How often does the Earth get a close encounter?
- Objects with diameters of
16-30 ft / 5-10 mimpact the Earth’s atmosphere approximately once per year. These ordinarily explode in the upper atmosphere, and most or all of the solids are vaporized- These can produce as much energy as the atomic bomb dropped on Hiroshima
- ~15,000 tonnes of TNT
- Every 2000–3000 years NEAs produce explosions comparable to the one observed at Tunguska in 1908
- Objects with a diameter of one kilometer hit the Earth an average of twice every million year interval
- Large collisions with five kilometer objects happen approximately once every ten million years.
Impact Craters on Earth
- It was around the turn of the century that the idea that craters were due to impacts rather than volcanism.
- Grove Karl Gilbert : In 1892 Gilbert would be among the first to propose that the moon’s craters were caused by impact rather than volcanism
- Daniel Barringer : In 1903, mining engineer and businessman Daniel M. Barringer suggested that the crater had been produced by the impact of a large iron-metallic meteorite.
- It wasn’t until 1960 that we had definitive proof that there were actual impact craters on Earth.
- This was proved by Eugene Shoemaker, the same guy who co-discovered the comet Shoemaker-Levy 9 that hit Jupiter in 1994, studying Meteor Crater in Arizona.
- The key discovery was the presence in the crater of the mineral stishovite, a rare form of silica found only where quartz-bearing rocks have been severely shocked by an instantaneous overpressure.
- Where are all the Earth impact we know about?
How do we categorize the danger level?
- Palermo Technical Impact Hazard Scale : a logarithmic scale used by astronomers to rate the potential hazard of impact of a near-earth object (NEO) and combines two types of data; probability of impact, and estimated kinetic yield, into a single “hazard” value.
- A rating of 0 indicates a low hazard level
- A rating of +2 would indicate the hazard is 100 times more likely
- Torino Scale : a method for categorizing the impact hazard associated with near-Earth objects (NEOs) such as asteroids and comets. It is intended as a tool for astronomers and the public to assess the seriousness of collision predictions, by combining probability statistics and known kinetic damage potentials into a single threat value.
NEO Asteroid 99942 : Apophis
- Diameter : 886 ft / 270 m
- 2.9 x height Statue of Liberty [ 306 ft / 93.47 m ]
- 2 x height of Pyramids of Giza [ 449.5 ft / 137 m ]
- Rotation : 30.4 h
- Mass [ 59,524,810,800 lb / 27,000,000,000 kg ]
- 4.5 x Great Pyramids of Giza : 13,227,735,700 lb / 6,000,000,000 kg
- 519 x RMS Titantic : 114,640,376 lb / 52,000,000 kg
- Caused a brief period of concern in December 2004 because initial observations indicated a small probability (up to 2.7%) that it would strike the Earth in 2029.
- Additional observations provided improved predictions that eliminated the possibility of an impact on Earth or the Moon in 2029
- However, a possibility remained that during the 2029 close encounter with Earth, Apophis would pass through a gravitational keyhole, a precise region in space no more than about a half-mile wide, that would set up a future impact on April 13, 2036.
- This possibility kept the asteroid at Level 1 on the Torino impact hazard scale until August 2006, when the probability that Apophis will pass through the keyhole was determined to be very small.
- Apophis broke the record for the highest level on the Torino Scale, being, for only a short time, a level 4, before it was lowered
NEO Asteroid 99942 : Apophis what DID NOT happen
- Apophis Path of Risk
- Energy Estimates were originally equivalent of 1480 megatons of TNT, but were later refined to estimate was 880 megatons, then revised to 510 megatons
- Barringer Crater or the Tunguska event are estimated to be in the 3–10 megaton range
- Biggest hydrogen bomb ever exploded, the Tsar Bomba, was around 50 megatons
- Krakatoa was the equivalent of roughly 200 megatons
- Chicxulub impact has been estimated to have released about as much energy as 100,000,000 megatons
- It was estimated that the hypothetical impact of Apophis in countries such as Colombia and Venezuela, which are in the path of risk, could have more than 10 million casualties
DAWN Spacecraft (http://dawn.jpl.nasa.gov/)
- Science Payload that includes : Camera’s, Visible and Infrared Spectrometer, Gamma Ray and Neutron Spectrometer (GraND), and Gravity Science
- Images of Vesta and Ceres in three colors and black and white
- Full surface with mapping spectrometer
- In three bands, 0.35 to 0.9 micron, 0.8 to 2.5 micron and 2.4 to 5.0 micron
- Neutron and gamma ray spectra to produce maps of the surface elemental composition of each asteroid
- Including the abundance of major rock-forming elements (O, Mg, Al, Si, Ca, Ti, and Fe), trace elements (Gd and Sm), long-lived radioactive elements (K, Th, and U), and light elements such as H, C, and N, which are the major constituents of ices.
- Radio tracking to determine mass, gravity field, principal axes, rotational axis and moments of inertia.
Other Spacecraft Missions to Comets & Asteroids
Near-Earth Asteroid Rendezvous (NEAR)
Deep Impact
Deep Space 1 (DS1)
STARDUST
Hayabusa (MUSES-C)
Rosetta
EPOXI
Stardust-NExT
Additional Research Material
Interactive : Impact Earth!
NASA : Near Earth Object Program
Meteor Crater / Barringer Crater
WIKI : East Antarctica Crater
WIKI : Near Earth Object
WIKI : List of impact craters on Earth
WIKI : Tunguska event
WIKI : Chicxulub crater
WIKI : Meteor Crater
Tracking Study’s or Groups
Asiago-DLR Asteroid Survey
Japan Spaceguard Association
Campo Imperatore Near-Earth Object Survey
Catalina Sky Survey
Lowell Observatory Near-Earth-Object Search
Space Watch
Near Earth Asteroid Tracking
The Lincoln Near-Earth Asteroid Research
Social Media
Facebook : Asiago-DLR Asteroid Survey
Facebook : Campo Imperatore Near-Earth Object Survey
Facebook : Catalina Sky Survey
Facebook : Near Earth Asteroid Tracking
Facebook : The Lincoln Near-Earth Asteroid Research
Twitter : Catalina Sky Survey
Related News Stories
NASA : Near Earth Object News
NASA : Asteroid 2005 YU55 to Approach Earth on November 8, 2011
NASA : 2010 TK7: The First Earth Trojan Asteroid
ScienceNews.com : Five days after being discovered, an interplanetary visitor whizzes past
National Geographic : Huge Impact Crater Found in Remote Congo (March 2011)
National Geographic : “Fresh” Crater Found in Egypt; Changes Impact Risk? (July 2010)
National Geographic : India Asteroid Killed Dinosaurs, Made Largest Crater? (Oct 2009)
Wired : Asteroid Impact Craters on Earth as Seen From Space (Aug 2009)
National Geographic : Huge Impact Crater Uncovered in Canadian Forest (Nov 2008)
National Geographic : Giant Meteor Fireball Explodes Over Northwest U.S. (Feb 2008)
National Geographic : Crater From 1908 Russian Space Impact Found, Team Says (Nov 2007)
National Geographic : Photo in the News: Mysterious Space Object Crashes Into House (Jan 2007)
National Geographic : Meteorite Impact Reformulated Earth’s Crust, Study Shows (Jan 2006)