"ATI-on/WoRkD The Michigan Daily - Friday, December 8, 1995 - 11A GAILEO SEES THE MANY MOONS OF JUPITER *I Spacecraft enters atmosphere of Jupiter, sends data PASADENA, Calif. (AP)-- A 746- pound probe from the Galileo space- craft entered the harsh, whirling gases of Jupiter's atmosphere yesterday and sent back 75 minutes of precious data before it disintegrated. After receiving weather and chemi- cal data from the probe, Galileo fired its thrusters to push the spacecraft into orbit around Jupiter for two years of study. NASA workers cheered and there were handshakes and back slaps all around when it was confirmed at 3:15 p.m. that the probe was transmitting information back to its trailing Galileo mother ship. "Fantastic!" said Torrence Johnson, Galileo project scientist at NASA's Jet Propulsion Laboratory in Pasadena. "Wow! You never really believe it till you see it." After slamming into the atmosphere at 106,000 mph, the giant, squat cone dropped more than 125 miles by para- clfute, sending data for 75 minutes be- fore being crushed by air pressure 20 times greater than Earth's. U'libraryI By Scot Woods Daily News Editor The arrival of the Galileo probe at the Jovian system is the latest stage ofnearly iOur centuries of investigation of the solar system's largest planet. NASA's interplanetary traveleris the namesake of Jupiter's first explorer, 17th-century Italian astronomer Galileo Galilei, who turned his spyglass sky- ward early in January of 1610. The University is fortunate to pos- sess the actual manuscript of Galileo's notes from those winter nights when he first discovered Jupiter's four brightest moons (See illustration). Curators at the Harlan Hatcher Gradu- ate Library say the document, written in Italian, is of great historical value be- cause it is a working document, not a final, published product. "In some ways, it shows the work- ings of his mind," said Peggy Daub, head of special collections and arts li- braries at the University. "Usually, what we have is the nice, clean, final copies. In this case, he seemed to be trying out different theories." Humanities collections Curator Kathryn Beam said, "Besides being an oiiginal Galileo manuscript, the con- teint itself is significant because of its likely being the first observations ofthe moons of Jupiter." Excited by his discovery, Galileo rushed to publish his findings by that March. The manuscript came into the University's possession in 1938, when Detroit resident Tracy McGregor do- nated part of his collection. McGregor had purchased the manuscript in 1934 at an auction. Nobody knew what a treasure the University had until an extensive ar- ticle on the piece appeared in "Scien- tific American" in 1976. Since then, the document has been cited often by schol- ars. Galileo's notes are written on the bottom third ofa sheet of paper that also contains the draft of a letter to the doge - or prince - of Venice, written at "We've never, never sampled a giant planet. We'll figure out what this atmo- sphere is made of over 600 million miles away," said Wesley T. Huntress, NASA associate administrator for space science. Previous space missions have ana- lyzed the atmospheres of Mars and Venus. But Jupiter is different; the gi- ant planet is surrounded by powerful magnetic fields and intense radiation, and is made up mostly of hydrogen and helium, the elements in the primordial mix that once condensed into the solar system. Scientists monitoring the events on Scientist closed-circuit television in an audito- Sinit rium at the laboratory burst into ap- plause again after getting confirmation well as t that Galileo had begun a 49-minute magnetic engine burn to send the spacecraft into and charg orbit. "We've done it! We've got con- give the 1 firmation," said Richard Terrile, a composit NASA scientist. Up to t The orbits around Jupiter are expected traterrest to provide images of eight ofthe planet's the Hub 16 known moons. mirror is By illuminating Jupiter's moons, as "YouI owns Galileo's A monitor Information from the Galileo spacecraft at NASA's Jet Propulsion Laboratory in Pasadena, Calif.v he planet's rings, its intense field and its swarms of dust ged particles, the mission could best view ever of the planet's tion. now, the best glimpses of ex- rial bodies have come from ble Space Telescope, whose less than 8 feet across. would need a Hubble Space notes on Telescope over 10 miles in diameter to ammonia crystal clouds get images of the moons as good," a stew of ammonia coi Johnson said. "There's no substitute in ing in hurricane windsi this business for getting your instru- After that, scientists& ments up close." would probably encou Detailed data from the atmospheric and lightning before b encounter won't be available until mid- by the heat and pressur December at the earliest. "The probe is ... rec Scientists speculated that after the the most important in probe passed through a high layer of the solar system," John ijupiter discovery s, it would reach mpounds swirl- up to 200 mph. said, the probe nter heavy rain eing vaporized re. ording some of formation from son said. Planet's immensity creates curiosity Los Angeles Times It's not surprising that Jupiter was. named after the head honcho of the ancient gods. It has everything other planets have, and then some. Sitting on the borderline between planet and star, Jupiter "is about as big aplanet as you can make," said Torrence Johnson, a Galileo project scientist with Jet Propulsion Laboratory. Yet its fierce gravitational contraction causes it to "shine," radiating twice the energy it receives from the sun. Just why Jupiter got to be so im- mense - 1,300 times the size of Earth - remains something of a mystery, although Johnson explains that the gi- ant simply may have started gobbling up matter before the other planets be- gan to condense out of the cloud; before long, it would have had a strong gravi-. tationally grip on all matter in its local area. The composition of Jupiter is es- sentially the same as the sun - mostly hydrogen and helium. But because Jupiter isn't quite big enough to ig- nite a nuclear fire in its belly and become a star, it hasn't altered the composition of the matter it was= formed with. At the same time, its. huge gravity has kept matter from boiling off or blowing away. That makes it a perfect pristine labo-.. ratory to study the stuff that went into' making our solar system. Its huge grav- ity has allowed nothing to escape its grasp; and the matter it started with wouldn't have changed its form. Jupiter's weather also offers lessons in stellar and planetary atmospheric' science. In a sense, the entire planet is an atmosphere, since it's gas all the way down until pressure turns hydrogen into a metallic liquid thousands of miles down (although some scientists think' the core may be rocky). Swirling orange-brown ammonia clouds paint stripes on the rapidly spin ning sphere, which rotates in a 10-hour day. At the equator, winds get up to 250 mph, then reverse direction, then re verse again, causing bands of colors and eddies near the borders. "It's a major puzzle what drives these wind systems," said JPL probe scientist Rich" Young. 7--4 ~~ ~.OF ,f :. 4,1 * 44 Photo courtesy of NEWS AND INFORMATION SERVICES The University possesses the above manuscript of Galileo, in which he recorded his discovery of Jupiter's four brightest moons. Translation The following is the English translation of Galileo's original Latin manuscript, written Jan. 7-15, 1610. On the 7th of January Jupiter is seen as thusXwest east 4( On the 8th thus it was therefore direct and not retrograde. On the 12th day it is seen in this arrangement The 13th are seen very close to Jupiter 4 stars or better so On the 14th it is cloudy. The 15th the nearest to Jupiter was smallest the 4th was distant from the 3rd about double. The spacing of the 3 to the west was no greater than the diameter. and they were in a straight line. ect t * the st I I ~ III least three months earlier. "We know there was a finished letter actually sent to the doge in August 1609," Beam said The letter draft adds greatly to the value of the manuscript. "It's a full two-thirds ofa page in Galileo's hand. It has significance for his recognition of the telescope as a useful tool," she said. The letter describes "a telescope that will be a great help in maritime and land enterprises. ... The telescope has the advantage of discovering the ships of the enemy two hours before they can be seen with the natural vision and to dis- tinguish the number and quality of the ships and to judge their strength and be ready to chase them, to fight them, or to flee from them." The draft notably does not men- tion use of the telescope as an instru- ment for investigating the heavens. That idea would have been consid- ered dangerous because, as Galileo proved, it had the potential to under- mine the concept of an earth-cen- tered universe taught by the Roman Catholic Church. Nicolaus Copernicus had already challenged the church with his theory of a sun-centered universe in 1540. "(Galileo's observations) showed that things revolved around objects other than the Earth," Daub said. By exten- sion, this discovery suggested that the Earth might orbit the sun. Beam said this page, the library's .only manuscript in Galileo's hand, is used regularly by publishers."It's been used more in textbooks to introduce high school students to the significance of Galileo," she said. - "l u-EIG " I E"B -read them Daily 100s of Christmas Videos in stock Tower's Top 40 Books on Sale. How The Grinch Stole Christmas on sale $9.99 The Real World on sale $11.20 N I A Charlie Brown Christmas on sale $9.99 The Crossing Guard on sale $16.07 A Christmas Story on sale $10.99 '1'. Four Rooms on sale $6.97 Don't Panic!! If you think you're pregnant... call us-we listen, we care. PROBLEM PREGNANCY HELP 769-7283 Any time, any day, 24 hours. Fully confidential. Serving Students since 1970. sale ends 12/18/95 £ sale ends 12/18/95 All Classical and Opera CDs on Sale sale ends Monday 12/11/95 at Midnight Check out our "Buy this CD, get this stuff Free" rack. It has free T-shirts, candles & BBQ sauce. 11 Attenti A ertisers Due to the 11 Bring in this pp, .,. ~ .v..Sayx. v ^at .k > .f..y..M.3.w nas.,sti ; a x^sa . . a ..a, .,r. .;i 'a:.mn.,rc.,.., .....a. . r - fmu is