Quake Damages Hawaii Telescopes
WAIMEA, Hawaii, Oct. 20, 2006 -- While their telescopes' huge mirrors escaped unharmed, scientists at the 13 powerful and technologically advanced telescopes circling the dormant Mauna Kea volcano have reported damage to other equipment vital to the instruments in the days following Sunday's 6.7-magnitude earthquake and aftershocks.
W.M. Keck Observatory machinist Neil Felton shows what 100,000 pounds of force can do to an earthquake restraint pad which was removed from the Keck I telescope during earthquake recovery efforts. (Photo: Sarah Anderson)
The earthquake struck off the west coast of Hawaii at 7:07 a.m. on Sunday. It was the largest to hit Hawaii in 20 years and caused power and communication failures across the state. None of the observatories reported any injuries or damage to computers or servers. Many of the observatories canceled skygazing sessions until the end of this week while equipment was assessed for damage.
From reports as of Thursday, it appeared that the W.M. Keck Observatory, home to the twin Keck optical and infrared telescopes, and the Canada-France-Hawaii Telescope, a 3.6 meter optical infrared telescope, sustained most of the damage.
While the Keck telescopes' mirrors and optics were not damaged, the radial pads and brakes that support the 300-ton structures on their mounts must be removed and replaced, Laura Kinoshita, an observatory spokeswoman, told the Associated Press.
She told the AP that an inspection showed the telescopes came down on the radial pads and brakes with about 100,000 pounds of force during Sunday's temblor. Because software uses the telescope's previous location to tell the scientists where in the sky it is now pointed, observatory engineers will have to recalibrate both telescopes to account for the seismic shifts that moved the Keck I telescope more than 1/8 inch and the Keck II telescope more than one inch, Kinoshita said.
"In astronomy, even a movement by a few nanometers makes a significant impact on the accuracy of our systems," Kinoshita told the AP. "So we need to update our systems to factor in the new position of the telescope."
The summit of Mauna Kea on the island of Hawaii hosts the world's largest astronomical observatory, with telescopes operated by astronomers from 11 countries. There are currently 13 working telescopes near the summit; nine are for optical and infrared astronomy, three are for submillimeter wavelength astronomy and one is for radio astronomy.
"Keck Observatory technical staff are working long hours at the summit to repair the systems damaged in the earthquake and to verify the proper functioning of the many precision systems required to operate a state-of-the-art telescope. I am struck by the dedication and resourcefulness of the staff performing these activities. We are all eager for the Keck telescopes to resume observing and astronomical discovery,” said Observatory Director Dr. Taft Armandroff in a statement posted Thursday morning on the Keck Web site.
According to the Web site, Thursday night was to be an engineering night, used to align the Keck I telescope and update the observatory's pointing models. If new parts were delivered quickly, the observatory said Keck II could be operational as early as the middle of next week.
The Canada-France-Hawaii Telescope (CFHT) needed to have its encoder assembly, a device that helps astronomers keep track of what part of the sky they are observing, replaced. A chunk was taken out of the old one when the earthquake lifted the telescope up and down.
"That device has been smashed and crushed by the telescope at the time of the main shake," Veillet told the AP. "It looks like you took some butter out of it with your knife, and it's really solid steel we are talking about."
Side view showing damage to the encoder on the Canada-France-Hawaii Telescope.
Once the telescope was operational again and the pointing was checked. "We were of by a few tens of arc-seconds, not a surprise as the absolute encoders are likely to have moved with respect to the telescope itself.Subsequent pointing all around the sky were as good as usual once the initial offsets had been removed. So, nothing really changed and the telescope was back as good as before," CFHT reported on its Web site on Thursday.
The Gemini Observatory, home to The Frederick C. Gillett Gemini North Telescope, said on its Web site that it was performing extensive tests to determine if the telescope was damaged.
"The observatory clearly shook hard during this event and there is evidence that the telescope moved on the hydrostatic bearing surfaces (without oil of course). There is also evidence that the earthquake restraint system may have engaged as well, this being the ultimate fallback to prevent the telescope from tipping over on the main support pier," the observatory said.
The NASA Infrared Telescope Facility (IRTF) reported on its Web site Tuesday that it didn't receive any significant damage, and that it had opened for observations of Saturn that morning and was operating normally.
A visual inspection of the optical infrared Subaru Telescope revealed it had avoided major damage. The National Astronomical Observatory of Japan, where the telescope is housed, said the telescope and its observing instruments would continue to be carefully assessed for damage.
For more information on the Mauna Kea observatories, visit: www.ifa.hawaii.edu/mko
- The scientific observation of celestial radiation that has reached the vicinity of Earth, and the interpretation of these observations to determine the characteristics of the extraterrestrial bodies and phenomena that have emitted the radiation.
- Pertaining to optics and the phenomena of light.
- An afocal optical device made up of lenses or mirrors, usually with a magnification greater than unity, that renders distant objects more distinct, by enlarging their images on the retina.
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