Asteroid Flyby Near Earth, Manila Wednesday Morning

When an asteroid the size of an aircraft carrier makes its flyby near Earth Wednesday morning (Manila time), the weather will be clear enough for it to be seen, state astronomers said Tuesday.

The Philippine Atmospheric Geophysical and Astronomical Services Administration also allayed fears that the asteroid, codenamed YU55, will hit the Earth with catastrophic results. "Ang alam ko hindi magiging maulap dahil maganda ang panahon, maaari nating makita [ang asteroid]," PAGASA forecaster Elvie Enriquez said in an interview on dzBB radio.

An article on UK's The Daily Mail said the asteroid will not be visible to the naked eye, but amateur astronomers could see it "if they use a telescope at least 6 inches in diameter as it approaches from a sunward direction."

In the same radio interview, Enriquez dismissed doomsday scenarios as shown in movies, as she stressed YU55 will only pass by the Earth and will not crash into it. "Dadaan lang (ito), hindi tulad ng pinapanood natin [sa] sine. Hindi yan ia-allow ni Lord. Makikita lang natin ang kanyang kagandahan," she said.

The UK Daily Mail cited experts who calculated that if something of that size were to hit Earth, it would cause a 4,000 megaton blast, a magnitude 7.0 earthquake, and if it hit water a 70-foot high tsunami would spread within 60 miles of the crash site.

The asteroid’s closest passage is expected at 5:28 p.m. CST (7:28 a.m. Manila time). Earlier, the National Space and Aeronautics Administration said asteroid YU55 will not hit Earth, and are making preparations to track it. "The trajectory of asteroid 2005 YU55 is well understood. 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. 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 said.

NASA said 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. It said the next known approach of an asteroid this large will be in 2028.

For the November flyby, NASA scientists will use antennas of its Deep Space Network at Goldstone, California, to track the asteroid. It said it will track the asteroid starting at 9:30 a.m. local time (PDT) on Nov. 4, using a massive 70-meter Deep Space Network antenna, for about two hours.

Goldstone will continue tracking the asteroid for at least four hours each day from Nov. 6 through Nov. 10. Radar observations from the Arecibo Planetary Radar Facility in Puerto Rico will begin on Nov. 8, the same day the asteroid will make its closest approach to Earth at 3:28 p.m. PST. "Although 2005 YU55 is in an orbit that regularly brings it to the vicinity of Earth (and Venus and Mars), the 2011 encounter with Earth is the closest this space rock has come for at least the last 200 years," NASA said.

NASA scientists hope to obtain images of the asteroid from Goldstone as fine as about 7 feet (2 meters) per pixel. This should reveal a wealth of detail about the asteroid's surface features, shape, dimensions and other physical properties. Arecibo radar observations of asteroid 2005 YU55 made in 2010 show it to be approximately spherical in shape.

It is slowly spinning, with a rotation period of about 18 hours. The asteroid's surface is darker than charcoal at optical wavelengths. "Amateur astronomers who want to get a glimpse at YU55 will need a telescope with an aperture of 6 inches (15 centimeters) or larger," NASA said.