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Sunday, May 1, 2011

Small Asteroid to Pass Within Earth-Moon System Tuesday

A newly-discovered car-sized asteroid will fly past Earth early Tuesday.  

A newly discovered car-sized asteroid will fly past Earth early Tuesday. The asteroid, 2010 TD54, will make its closest approach to Earth at 6:51 EDT a.m. (3:51 a.m. PDT). Image credit: NASA/JPL 

PASADENA, Calif. -- A small asteroid will fly past Earth early Tuesday within the Earth-moon system. The asteroid, 2010 TD54, will have its closest approach to Earth's surface at an altitude of about 45,000 kilometers (27,960 miles) at 6:50 EDT a.m. (3:50 a.m. PDT). At that time, the asteroid will be over southeastern Asia in the vicinity of Singapore. During its flyby, Asteroid 2010 TD54 has zero probability of impacting Earth. A telescope of the NASA-sponsored Catalina Sky Survey north of Tucson, Arizona discovered 2010 TD54 on Oct. 9 at (12:55 a.m. PDT) during routine monitoring of the skies.

2010 TD54 is estimated to be about 5 to 10 meters (16 to 33 feet) wide. Due to its small size, the asteroid would require a telescope of moderate size to be viewed. A five-meter-sized near-Earth asteroid from the undiscovered population of about 30 million would be expected to pass daily within a lunar distance, and one might strike Earth's atmosphere about every 2 years on average. If an asteroid of the size of 2010 TD54 were to enter Earth's atmosphere, it would be expected to burn up high in the atmosphere and cause no damage to Earth's surface.

The distance used on the Near Earth Object page is always the calculated distance from the center of Earth. The distance stated for 2010 TD54 is 52,000 kilometers (32,000 miles). To get the distance it will pass from Earth's surface you need to subtract the distance from the center to the surface (which varies over the planet), or about one Earth radii. That puts the pass distance at about 45,500 kilometers (28,000 miles) above the planet. NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground-and space-based telescopes. 

The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and plots their orbits to determine if any could be potentially hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena.

More information about asteroids is available at http://www.jpl.nasa.gov/asteroidwatch/ . You can also follow the latest news about asteroids on Twitter at @asteroidwatch .
A technician makes his way across a platform in Endeavour's aft section. 

Image above: At NASA Kennedy Space Center's Launch Pad 39A, a technician makes his way across a platform in space shuttle Endeavour's aft section as work begins to remove and replace the aft load control assembly-2 (ALCA-2). Photo credit: NASA/Kim

The crew members for space shuttle Endeavour's STS-134 mission are Commander Mark Kelly, Pilot Gregory H. Johnson and Mission Specialists Michael Fincke, Greg Chamitoff, Andrew Feustel and European Space Agency astronaut Roberto Vittori.

During the 14-day mission, Endeavour and its crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre.

Teams to Replace APU Heater Power Box; Launch No Earlier than May 8

Technicians and engineers at NASA's Kennedy Space Center in Florida have identified the likely source of what caused heaters on a fuel line for space shuttle Endeavour's auxiliary power unit-1 (APU-1) to fail on Friday, scrubbing the first launch attempt for the STS-134 mission. The failure appears to be a power problem within the aft load control assembly-2 (ALCA-2), a box of switches controlling power feeds.

"That basically means the power is not getting out to the heaters that weren't working on launch day," said Space Shuttle Program Launch Integration Manager Mike Moses.

The plan is to remove and replace the box, but that work and related testing will take several days to complete. Once the new box is installed, the team must verify it's working properly -- at least a two-day process -- and perform forensics on the failed box.

"We can tell you, pretty much, that it's not going to be any earlier than (May 8)," Moses said. "We're really not even setting the schedules today. There's still a whole lot of short-term work that has to be done."

Endeavour's six astronauts have returned to NASA's Johnson Space Center in Houston for a few days of additional training before they report to Kennedy for the next launch attempt, and the crew's families also are going to return home today. The launch team is backing out of launch countdown operations.

"Responding to problems is one of the things we do best around here, and the team always likes a good challenge," said Shuttle Launch Director Mike Leinbach. "I'm sure we're going to be really glad when Endeavour's finally on orbit, but right now, the team is upbeat and ready to execute."

The Great 2012 Doomsday Scare


Scenes from the motion picture  



The year 2012 is acting like a badly behaved celebrity. Frightful rumors and gossip are spreading. Already more than a half dozen books are marketing, to eager fans, astronomical fears about 2012 End Times. Opening in theaters on Friday, Nov. 13, will be 2012, a $200-million disaster movie that seems designed to break all records for disaster spectacles -- with cracking continents, plunging asteroids, burning cities, and a tsunami throwing an aircraft carrier through the White House. The movie's ominous slogan: "Find out the truth." Two other major movies about the 2012 doomsday are also reported to be in the works.

Anyone who cruises the internet or all-night talk radio knows why. The ancient Maya of Mexico and Guatemala kept a calendar that is about to roll up the red carpet of time, swing the solar system into transcendental alignment with the heart of the Milky Way, and turn Earth into a bowling pin for a rogue planet heading down our alley for a strike.

None of it is true. People you know, however, are likely becoming a bit afraid that modern astronomy and Maya secrets are indeed conspiring to bring our doom. If people know you’re an astronomer, they will soon be asking you all about it.

Here is what you need to know.

Birth of a Notion
We"ve had similar scares in the recent past, but none quite like this. The last time the world got all worked up over the mystical turning of a calendar was the false Millennium of Jan. 1, 2000. Never mind the actual Y2K computer-date bug. True-believer authors  published scary and/or hopeful books about the moment's prophetic potential to catch an immense cosmic wave and change everything for either good or ill. Borrowing a forecast from Nostradamus, the 16th-century French riddler, author Charles Berlitz predicted catastrophe in his 1981 book Doomsday 1999. Berlitz warned that 1999 could inflict flood, famine, pollution and a shift of Earth's magnetic poles. He also spotlighted the planetary alignment of May 5, 2000, and warned that it could bring solar flares, severe earthquakes, "land changes" and "seismic explosions."

In the 1990s an entire "Earth Changes" movement swelled into being as the end of the century neared, with all sorts of Millennial expectations -- earthquakes, plagues, polar axis shifts, continents sliding into the sea, Atlantis rising and more. In England, the Sun tabloid predicted a "marvelous millennium of joy, peace, prosperity."

When Jan. 1, 2000, came and went with nothing worse than ski-lift passes printing the date as 1900, the focus shifted to "5/5/2000" several months later. Most believers in the power of planetary alignments forgot the failure of earlier lineups to induce disaster. The "Jupiter Effect" cataclysm predicted for March 10, 1982 (named for the 1974 book about it by John Gribbin and Stephen Plagemann) commanded headlines but never materialized.

Throughout history, end-of-the-world movements missing their mark number in the "hundreds of thousands at the very least, says Richard Landes, historian at Boston University and director of its Center for Millennial Studies. But people eager for the world to end are not to be denied, and this time, of course, all will be different.

The Rollover
What exactly is the Maya calendar about to do? On Dec. 21, 2012, it will display the equivalent of a string of zeros, like the odometer turning over on your car, with the close of something like a millennium. In Maya calendrics, however, it's not the end of a thousand years. It's the end of Baktun 13. The Maya calendar was based on multiple cycles of time, and the baktun was one of them. A baktun is 144,000 days: a little more than 394 years.

Scholars have deciphered how the Maya calendar worked from historical texts and ancient inscriptions, and they have accurately correlated so-called Maya Long Count dates with the equivalent dates in our calendar. Just as we number our years counting from a historically and culturally significant event (the presumed birth year of Christ), Maya times were numbered from a date endowed with religious and cosmic significance: the creation date of the present world order. A Long Count date is the tally of days from that mythic startup. Most experts think the start point corresponds to Aug. 11, 3114 B.C.

Most of the Maya calendar intervals accumulate as multiples of 20. An interval of 7,200 days (360 × 20) was known as a katun. It takes 20 katuns to complete a baktun (20 × 7,200 = 144,000 days). Although some ancient inscriptions turn 13 baktuns into an important reset milestone, others imply that the calendar simply keeps running. For instance, it takes 20 baktuns to make a pictun.

No one paid much attention to the end of Baktun 13 until fairly recently. In 1975 Frank Waters, a romantic and speculative author, devoted a brief section to the subject in his book Mexico Mystique. He identified the 13-baktun interval as a "Mayan Great Cycle," overestimated its duration as 5,200 years, and equated five such cycles with five legendary eras, each of which ends in the world’s destruction and rebirth. There is no genuine Maya tradition behind any of this.

Waters also miscalculated the date when the calendar would supposedly pull down the shades. "The end of the Great Cycle . . . will occur Dec. 24, 2011 A.D.," he announced, when the world "will be destroyed by catastrophic earthquakes." Exact date aside, the doomsday ball was now rolling.

Another book in 1975 also spotlighted the Maya calendric roundup. Dennis and Terence McKenna discussed it in The Invisible Landscape: Mind, Hallucinogens, and the I Ching. That book at least got the Baktun-13 end date right: Dec. 21, 2012. It also noted that the date is the winter solstice, when the Sun will be "in the constellation Sagittarius, only about 3 degrees from the Galactic Center, which, also coincidentally, is within 2 degrees of the ecliptic." The McKennas continued, "Because the winter solstice node is precessing, it is moving closer and closer to the point on the ecliptic where it will eclipse the galactic center." In reality this event will never happen, but it hardly matters. The McKennas linked the whole arrangement with the concept of renewal and called 2012 a moment of "potential transformative opportunity."

Broader interest in 2012 caught on beginning in 1987. In The Mayan Factor: Path Beyond Technology, José Argüelles (an "artist, poet, and visionary historian" according to the dust jacket) linked the 13-baktun period with an impalpable "beam" from the center of the Milky Way Galaxy. According to Argüelles, the Maya knew when we entered this beam and when we would leave it, and set their 13-baktun cycle to mark our passage through it accordingly. The beam, he asserted, operates as "invisible galactic life threads" that link people, the planet, the Sun, and the center of the Galaxy. Neither Maya tradition nor modern astronomy supports a belief in any such beam. It stemmed instead from Argüelles’s personal philosophy, which emphasizes "the principle of harmonic resonance." Argüelles also concluded that the planets are "orbiting harmonic gyroscopes" that “play a role in the coordination of the beam," which advances the development of anything with DNA. The year 2012, therefore, will bring a rosy version of the apocalypse.

If this sounds a bit familiar, you're right. In 1987 Argüelles and his followers predicted, with worldwide fanfare, that Aug. 16–17 of that year would bring a Maya-Galactic "Harmonic Convergence." That event turned into a global phenomenon, with thousands gathering at Earth’s “acupuncture points” to create a "synchronized and unified bio-electromagnetic collective battery." Unfortunately, the date passed with nothing more than colorful newspaper stories and a Doonesbury satire. (A character explains earnestly that that the alignment could bring either "mass unification of divine and earth-plane selves," or perhaps nuclear annihilation. "Either way there will probably be a crafts fair.")

Galactic Guessing Games
Fast-forward to 1995. That year John Major Jenkins packaged several of these themes into Maya Cosmogenesis 2012. According to Jenkins, the winter-solstice point and the centerline of the Galaxy will line up exactly on Dec. 21. Arguing that this motivated the Maya to contrive the calendar to end on that date, Jenkins concludes that it will be "a tremendous transformation and opportunity for spiritual growth, a transition from one world age to another."

In fact, astronomy cannot pinpoint such a "galactic alignment" to within a year, much less a day. The alignment depends on the rather arbitrary modern definition of the galactic equator, and/or the visual appearance of the Milky Way. There is no precise definition of the Milky Way's edges -- they are very vague and depend on the clarity of your view. (Jenkins says that he personally established the Milky Way’s edges by viewing it from 11,000 feet, far above anywhere the Maya lived.) So to give a precise visual position for its centerline is not meaningful.

Jenkins did acknowledge that the winter-solstice Sun actually crosses the center of the Milky Way anytime between 1980 and 2016. Elsewhere he expands this approach zone to a 900-year period, and settles for an imprecise alignment to which Dec. 21, 2012, is arbitrarily and circularly assigned. Real astronomy does not support any match between the Baktun-13 end date and a galactic alignment. The advocates both admit and ignore this discrepancy.

It's almost a sidelight that the winter-solstice sun will never actually "eclipse" the galaxy's true center, the pointlike radio source marking the Milky Way's central black hole. Moreover, the winter-solstice sun won’t even pass closest to it on the sky for another 200 years. What did the Maya themselves think about End Times? There is no evidence that they saw the calendar and a world age ending in either transcendence or catastrophe on December 21, 2012. Some Maya Long Count texts refer to dates many baktuns past 13 and even into the next pictun and beyond. For instance, an inscription commissioned in the 7th century A.D. by King Pacal of Palenque predicts that an anniversary of his accession would be commemorated on Oct. 15, 4772.

In all of the Long Count texts discovered, transcribed, and translated, only one mentions the key date in 2012: Monument 6 at Tortuguero, a Maya site in the Mexican state of Tabasco. The text is damaged, but what remains does not imply the end of time.

The Secret NASA Conspiracy
Some advocates for the 2012 catastrophe say that what will actually cause the devastation is an alignment of planets. There is no planet alignment on the winter solstice in 2012. Nonetheless, advocates of doom connect the fictional alignment to astrological predictions or groundless claims about a reversal of Earth's magnetic field and unprecedented solar storms. Many internet postings and guests on all-night apocalyptic radio have elaborated on these themes.

In particular, several threads of irrational thought have created an internet phantom, the secret planet Nibiru. It's the bowling ball, and Earth is the pin. There is no such planet, though it is often equated with Eris, a plutoid orbiting safely and permanently beyond Pluto. Some insist, however, that a NASA conspiracy is in play and that Nibiru, looming in on the approach, can already be seen in broad daylight from the Southern Hemisphere. It was supposed to become visible from the Northern Hemisphere, too, by last May, but like a fickle blind date, it stood up those awaiting it.

Others on the Web, confused about the supposed alignment of the winter-solstice sun with the Milky Way's center, have declared that the Sun is now plummeting to the Milky Way’s center and dragging Earth with it. The predicted result? Earth’s polar axis will shift. Most of what's claimed for 2012 relies on wishful thinking, wild pseudoscientific folly, ignorance of astronomy, and a level of paranoia worthy of Night of the Living Dead.

So maybe the Maya were on to us after all. The clock is ticking. And it’s the end of the world as we know it.

 
 
E.C. Krupp, a Sky & Telescope contributing editor, is Director of Griffith Observatory in Los Angeles.