California Institute of Technology Engineering & Science Winter 1992 In this issue Keck Telescope Dedicated Gamma Ray Sky Science in the Schools Looking out Keck I's dome through the partially completed primary mirror. The mirror and its support. ing frame can be seen reflected in the secondary mirror. California Institute of Technology Engineering & Science Winter 1992 Volume LV, Number 2 2 Deep Into That Darkness Peering - by Douglas L. Smith The first of two ten-meter telescopes, collectively known as the W. M. Keck Observatory, is dedicated on the summit of Mauna Kea. The telescope should be open for business this year. 16 Exploring the Gamma Ray Sky - by Thomas A. Prince The Gamma Ray Observatory, less than a year in orbit, is yielding new insight into such exotic astrophysical objects as supernovae, neutron stars, and black holes. 26 Planting SEEDs - by Winifred J. Veronda A couple of Caltech professors (along with students, postdocs, and alumni) take hands-on science to Pasadena schoolchildren and their teachers. Departments 34 SURFboard: Chute the Works 37 Books: Five Billion Vodka Bottles to the Moon by Iosif Shklovsky 38 Letters 42 Random Walk On the cover: The Engineering & Science (ISSN 0013-7S12) is published quarterly, Gary W. Stupian summit of Mauna Kea Fall, Winter, Spring, and Summer, at the California Institute of President of the Alumni Association Technology, 1201 Easr California Boulevard, Pasadena, California is prime telescope Thomas W. Andersoo country. The W. M. 91125. Annual subscription $8.00 domestic; $20.00 foreign air mail; single copies $2.00. Third class postage paid at Pasadena, Vice President for Institute Relations Keck Telescope, a California. All rights reserved. Reproduction of material contained Robert 1. O'Rourke joint venture of Cal· herein forbidden without authorization. © 1992 Alumni Associa­ AJJistant Vice President for Public Relations tech and the Universi· tion, California Institute of Technology. Published by the ty of California, is the California Institute of Technology and the Alumni Association. latest arrival. Keck II, Telephone: SlS-356-3630. Postmaster: Send change of address to its twin, will be Caltech 1-71, Pasadena, CA 91125. following shortly. PICTURE CREDITS: Cover, 2, 4, S, 11, 14, 34-36 - Bob Paz; inside front cover: 4, 6, 7,10, 15-DougSmith; 5,S-Steven STAFF: Editor-Jane Dietrich Simpson; 6 - Carol Lachata, JPL; 9,10,15, inside back (Over­ Writer - Douglas Smith CARA; 9 - P~ter French; 11 - Bill Varie; 12 - J. Anthony Tyson Copy Editors - Michael Farquhar, and Patrick Seitzer; 13 - Palomar; 13 - JPL; 17, IS, 22 - NASA; Danielle Gladding, Julie Hakewill 19 - Tom Weaver, Stan Woosley; 20 -Anglo-Australian Art Consultant - Barbara Wirick Observatory; 25 - Scientific American; 26-33 - Elizabeth Hamil­ BUJiness Manager - Debbie Bradbury ton; 35 - Garland Lee; 36 - Erik Taylor; 3S - Caltech Archives; Circulation Manager - Susan Lee 43 - Huntington Library, Ron Blom; 44 - Manny Delbriick Photographer - Robert Paz Deep Into That Darkness Peering Keck's size and instru­ mentation will make the most of by Douglas L. Smith the view. On Thursday, November 7,1991, some 150 already the world's largest telescope, yet only 18 invited spectators from Caltech, the University of its 36 hexagonal mirror segments had been in­ of California, and the W. M. Keck Foundation stalled. When the final segment is gently low­ joined the observatory staff to witness the dedica­ ered into place some time this spring, the 10- tion of the W. M. Keck Telescope and the meter Keck will have twice the diameter and four ground blessing of the site of Keck II. The twin times the light -gathering power of Caltech' s ven­ telescopes, collectively known as the W. M. Keck erable Hale Telescope; the world's premier opti­ Observatory, are the latest addition to an interna­ cal telescope for more than 40 years. (And when tional collection of eight others on the summit of Keck II, an identical telescope sited 93 yards Mauna Kea, on the Big Island of Hawaii-the away, becomes operational, the Kecks' combined world's finest astronomical site. (Mauna Kea has resolving power should be sufficient to detect all the advantages of other mountains of compara­ warm Jupiter-sized planets, should any be orbit­ ble height, plus the virtue of being on an island. ing Earth's closest stellar neighbors.) Wind takes the path of least resistance, going The VIPs-a few shivering in nylon wind­ Opposite: The Keck Telescope stands around the mountain rather than being forced breakers that had seemed more than adequate eight stories tall when over it, as happens with continental mountains. at the foot of the mountain-huddled in folding pointed at the zenith. Thus the air at the summit is very stable. And chairs on the dome's floor. The observatory staff there aren't any major air polluters-or even dust thronged the catwalk overhead, on a level with generators-for thousands of miles upwind, so the telescope itself. The ceremony proceeded the air is exceptionally clear.) from a dais set against the telescope's concrete It was a bright, windswept day at 13,600 feet, pedestal. The telescope was pointed at the hori­ well above the clouds that perpetually cling to zon so that its primary mirror, standing vertically Mauna Kea's slopes. Style took a back seat to at the tube's far end, served as both backdrop and comfort, as gloves, wool hats, and winter coats featured attraction. Kalena Silva, associate pro­ supplanted-or at least camouflaged-the jackets fessor of Hawaiian studies at the University of and ties normally associated with such rituals. Hawaii, gave the invocation-a Hawaiian chant, The bulk of the ceremony took place in the tele­ written for the occasion, blessing the telescope scope's dome, which shielded the crowd from the and all who will work there. Assorted dignitaries 15 mile-per-hour wind, but also blocked the sun­ made congratulatory speeches, and Monsignor shine that took the chill off of the 40-degree day. Charles Kekumano wrapped things up with If the thin, cold air wasn't enough to take another blessing in Hawaiian and English. And, one's breath away, the sight of nine tons of mirror finally, the telescope came to life. All watched in supported by blue-painted steel trusswork worthy silence as 150 tons of steel and glass, floating on a of a railroad trestle certainly was. At seven me­ few thousandths of an inch of oil, slowly began to ters (nearly 23 feet) in diameter, Keck I was pivot clockwise, as did the dome around them. Engineering & SciencelWinter 1992 3 Applause broke out as the telescope lifted its eye toward the heavens. Then the dome shutter raised itself with a clatter far louder than any noise the telescope had made. Sunlight flooded into the dome-a flood carefully cut off before it hit the mirror, which would have acted as one of the larger burning glasses since Archimedes. The crowd then trooped out of the dome, down the observatory hall, and out the far end of the building to a roped-off area, the site of Keck II's ground blessing. A line of 0'0 sticks-tradi­ tional Hawaiian digging implements-awaited the dignitaries, who dutifully seized them and lined up shoulder to shoulder in what proved to be the wrong direction. Confusion reigned briefly as the line re-formed under Kekumano's choreography. The phalanx of photographers, who had also been fooled, scrambled for new vantage points. The ceremony resumed and the Above: Now properly 0'0 sticks scrabbled briskly in the rust-red volcan- • oriented (from left), William Frazer, vice ic cinders, halting only when Kekumano dead­ chairman of CARA; panned, "That's enough dust, and there's no base­ Albert Simone, presi· ment necessary." Many key members of the Keck dent of the University of Hawaii; David Gard· I team have gone on to other things, but the les­ ner, president of the sons that they learned have already been incorpo­ University of Califor­ rated into Keck II's design. Work begins this nia; Howard Keck, chairman of the Keck spring on "The Bride of Keck," as it is sometimes Foundation; Thomas known, with completion set for 1996. The two Everhart, president of telescopes were conceived as a single astronomical Caltech; and Edward Stone, chairman of facility from the beginning, sharing utilities and CARA ply their 0'0 support staff, and even pooling their starlight sticks at the ground through a technique called optical interferometry. blessing. The sticks were of koa, a species The Keck Observatory is being built and oper­ of acacia native to the ated by the California Association for Research in Islands whose wood Astronomy (CARA), a partnership of Caltech and is prized for making ukuleles. the University of California, which will get the lion's share of the observing time. Caltech is funding the construction, primarily through a Right: Under the $70 million grant for Keck I and a $74.6 million telescope's second· grant for Keck II, both from the W. M. Keck ary·mirror cage, Silva Foundation. (Each telescope actually costs about chants the invocation. The ductwork below $94 million.) NASA has indicated its interest the catwalk is part of in obtaining one-sixth of the observing time in an air·handling sys· exchange for putting up a corresponding contri­ tem that can replace the entire volume of bution toward the construction cost. UC is air inside the dome covering the operating expenses for the first 25 with outside air every years, and funding the development of spectro­ five minutes. This prevents electrical graphic equipment being built by {.:altech and equipment (and hu· Uc.