50 Years Ago: The First Look at a Dry Mars

first_img Guido Münch in a 1967 portrait on his election to the National Academy of Sciences. Credit: James McClanahanIn 1964, Caltech astronomy professor Guido Münch and Jet Propulsion Laboratory space scientists Lewis Kaplan and Hyron Spinrad pushed the world’s second-largest telescope to its limits and dashed—at least for the next few decades—any hopes of finding liquid water on Mars.Back in the late 1800s, it was widely assumed that Mars was a planet with abundant water, just like Earth. Astronomers were mapping Mars’s polar caps, which advanced and retreated as the seasons changed; a dark “wave,” apparently of vegetation, which swept from the pole toward the equator every spring; and even ruler-straight lines that might have been canals dug by an alien civilization. Today, we know that the ice caps grow larger because the winters are cold enough to freeze carbon dioxide right out of Mars’s thin air; the seasonal darkening is a wind-driven redistribution of the dust that blankets the planet; and the canals were optical illusions enhanced by wishful thinking.The notion of a moist Mars began to evaporate at the turn of the 20th century. In 1909, Lick Observatory dispatched a team of astronomers to climb Mount Whitney—whose summit, at 14,500 feet, rises above some four-fifths of Earth’s atmospheric water vapor. Pointing a small telescope at Mars, the team measured no water vapor in excess of that in the rarefied air around them, although observatory director William Wallace Campbell cautioned the Associated Press that their technique, “the only method known, is not a sensitive one.” Campbell diplomatically noted that “the question of life under these conditions is the biologist’s problem rather than the astronomer’s.”Bigger telescopes make for more sensitive measurements, and by the 1920s the world’s largest telescopes were just north of Pasadena at the Mount Wilson Observatory. In 1926, observatory director Walter Adams and Charles St. John wrote in the Astrophysical Journal that “the quantity of water-vapor in the atmosphere of Mars, area for area, was 6 per cent of that over Mount Wilson . . . This indicates extreme desert conditions over the greater portion of the Martian hemisphere toward us at the time.” The 60-inch telescope they used was second in size and power only to the adjacent 100-inch Hooker telescope, with which Adams revisited the question in 1937 and 1939 and revised his figures downward. In 1941 he wrote, “If water vapor lines are present . . . they cannot be more than 5 per cent as strong as in the earth’s atmosphere and are probably very much less.”The “lines” Adams referred to are spectral ones. The spectrum of light contains all the colors of the rainbow, plus wavelengths beyond, that we can’t see. Every gas in the atmosphere—both Earth’s and Mars’s—absorbs a specific collection of these colors. Passing the light from a telescope through a device called a spectrograph spreads out the rainbow and reveals the missing wavelengths, allowing the gases that absorbed them to be identified.In those days, spectra were usually recorded as shades of gray on glass plates coated with a light-sensitive emulsion—essentially the same technique photographer Matthew Brady had used to document the Civil War. Once the plates were developed, the missing wavelengths showed up as black lines that were painstakingly analyzed under a microscope. Each line’s location indicated its wavelength, while its darkness and thickness were related to the absorber’s abundance. And therein lay the problem: the wide, black blots left on the plate by Earth’s dense blanket of air made the thin, faint lines from the tenuous atmosphere of Mars hard to see, let alone measure. The best opportunities to find the lines occur at approximately two-year intervals. Earth travels in a tighter orbit around the sun than Mars does, and as we pass Mars on the inside track our close approach maximizes the apparent difference in our velocities. This shifts Mars’s spectrum ever so slightly away from Earth’s—if you have an instrument powerful enough to discern the separation.Unfortunately, some passes are closer than others. When Earth overtook Mars in 1963, the latter was at the point in its orbit most distant from the sun. Although the two planets were as close to each other as they were going to get that time around, the velocity effect was minimized—imagine looking out the window of a moving train at a distant farmhouse instead of the nearby telephone poles. But the Hooker’s spectrograph had recently been upgraded; Kaplan and Spinrad were expert spectroscopists; and Münch was a wizard at making very sensitive emulsions, so the trio decided to look for the lines anyway. With little prospect for success, the experiment was allotted a set of low-value nights that began more than two months after Earth had passed Mars and started to pull ahead. At its closest approach, Mars had been 62,000,000 miles away; by the time Münch and company got their turn at the telescope, that distance had nearly doubled. Their telescope was no longer the best available, having been overtaken as the world’s largest by the 200-inch Hale telescope at Caltech’s Palomar Observatory. Even the weather conspired against them; four nights of work yielded exactly one usable exposure.But as Münch wrote in the January 1964 issue of the Astrophysical Journal, that “strongly hypersensitized” plate gave “a spectrogram of excellent quality which shows faint but unmistakable lines which have been ascribed to H20 in Mars’ atmosphere . . . After comparing our plate with other ones found in the Mount Wilson files, we have convinced ourselves that ours is the spectrogram of Mars with the highest resolving power ever taken.”Even so, the lines were barely strong enough to be usable. The preliminary water-vapor calculation, announced in May 1963, had an error factor of 10. It would take another six months to work out the definitive number—a figure equivalent to 0.01 ± 0.006 per cent of the amount of water vapor over Mount Wilson, and 100 times less than the 6 percent Adams and St. John had referred to as “extreme desert conditions” 40 years earlier. Furthermore, a slightly stronger carbon dioxide line enabled a direct estimate of Mars’s atmospheric pressure: 25 millibars (2.5 percent of Earth’s surface pressure)—one-quarter of the best previous estimates. (Munch and his collaborators noted in passing that although their value for carbon dioxide was not itself surprising, “what would appear indeed surprising is that the . . . value for the atmospheric pressure [is] so low that CO2 itself becomes a major constituent”—entirely unlike Earth, where nitrogen and oxygen make up 99 percent of the air we breathe.) Based on these results, Mars was now officially as arid as the moon, and nearly as airless.Confirmation would follow in 1965, when JPL’s Mariner 4 became the first spacecraft to visit Mars. The behavior of Mariner’s radio signal as the spacecraft passed behind Mars revealed that its actual atmospheric pressure was lower still: 5 to 9 millibars, or less than 1 percent of Earth’s. And the 20 televised pictures of Mars’s cratered, moonlike surface—some shot from as little as 6,000 miles above it—cemented the comparison.Professor of Physics Robert Leighton (BS ’41, MS ’44, PhD ’47), who had been the principal investigator on Mariner 4’s Television Experiment, as it was called, and Associate Professor of Planetary Science Bruce Murray, a member of the TV team, would use Münch’s and Mariner’s data as cross-checks on a detailed thermal model of Mars that they wrote for Caltech’s IBM 7094 mainframe computer—a pioneering feat in its own right. Their results, published in 1966, correctly predicted that most of Mars’s carbon dioxide was actually not in the atmosphere, but instead lay locked up in the polar caps in the form of dry ice; the paper also made the unprecedented suggestion that seasonal advance of each polar cap would freeze out so much carbon dioxide that the atmospheric pressure would drop by as much as 20 percent twice every Mars year. These predictions have since been confirmed many times over, and form part of our basic understanding of how Mars works.And what of water on present-day Mars, which is where this story began? Leighton and Murray wrote that “considerable quantities of water-ice permafrost may be present in the subsurface of the polar regions” just a few tens of centimeters down—permafrost that was finally discovered in 2002 by JPL’s Mars Odyssey mission.See more at: http://www.caltech.edu/content/50-years-ago-first-look-dry-mars#sthash.TlkAy65n.dpuf Science and Technology 50 Years Ago: The First Look at a Dry Mars By DOUGLAS SMITH Published on Thursday, May 8, 2014 | 11:00 am Make a comment EVENTS & ENTERTAINMENT | FOOD & DRINK | THE ARTS | REAL ESTATE | HOME & GARDEN | WELLNESS | SOCIAL SCENE | GETAWAYS | PARENTS & KIDS Top of the News faithfernandez More » ShareTweetShare on Google+Pin on PinterestSend with WhatsApp,Virtual Schools PasadenaHomes Solve Community/Gov/Pub SafetyCitizen Service CenterPASADENA EVENTS & ACTIVITIES CALENDARClick here for Movie Showtimes HerbeautyThese Are 15 Great Style Tips From Asian WomenHerbeautyHerbeautyHerbeautyAmazing Sparks Of On-Screen Chemistry From The 90-sHerbeautyHerbeautyHerbeautyHe Is Totally In Love With You If He Does These 7 ThingsHerbeautyHerbeautyHerbeautyWeird Types Of Massage Not Everyone Dares To TryHerbeautyHerbeautyHerbeautyIs It Bad To Give Your Boyfriend An Ultimatum?HerbeautyHerbeautyHerbeautyWant To Seriously Cut On Sugar? 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Cash injection to help disabled tenants in Limerick

first_imgNewsLocal NewsCash injection to help disabled tenants in LimerickBy Alan Jacques – August 14, 2014 542 Limerick Ladies National Football League opener to be streamed live Advertisement Limerick Artist ‘Willzee’ releases new Music Video – “A Dream of Peace” Email Limerick’s National Camogie League double header to be streamed live TAGSCllr Joe LeddinCommunity and Local GovernmentLabour PartylimerickLimerick City and County CouncilMinister of State at the Department of EnvironmentPaudie Coffey TD RELATED ARTICLESMORE FROM AUTHOR Twitter Linkedincenter_img Print Previous articleLimerick radio enthusiasts ham it up at Loop HeadNext articleEndurance Challenge aims to raise €500,000 Alan Jacqueshttp://www.limerickpost.ie Vanishing Ireland podcast documenting interviews with people over 70’s, looking for volunteers to share their stories Cllr Joe LeddinLABOUR councillor for City West Joe Leddin this week welcomed news that more than  €300,000 has been awarded to Limerick City and County Council as an additional top-up to help adapt homes for tenants living with a disability.Minister of State at the Department of Environment, Community and Local Government, Paudie Coffey TD, approved the sanction of €315,356 for local authority housing adaptions to meet needs of tenants with disabilities in Limerick.Sign up for the weekly Limerick Post newsletter Sign Up According to Cllr Leddin, this “cash injection” will be put to good use in Limerick and will help secure more comfortable accommodation for local authority residents with a disability.“Living with a disability often requires modifications to a standard family home. The Council can get to work on jobs such as widening doors, fitting wheelchair accessible bathrooms, and installing chairlifts, all small things which can make a huge difference,” said Cllr Leddin.“These essential works make the difference between living at home or becoming a long term patient in hospital. At a time when the housing budget is stretched to capacity, it is especially welcome that this money has been prioritised for this usage,” he added.Cllr Leddin also went on to urge Limerick City and County Council, where possible, to prioritise the services of local tradespeople in carrying out these new adaptions, so that the whole county can benefit from this cash announcement.Limerick Fine Gael TD, Dan Neville, also welcomed the funding.“Where new houses can’t be identified for tenants with disabilities, we must do everything we can to ensure that their houses are easier to live in and that is what this funding is intended to do”, said Deputy Neville. WhatsApp Facebook WATCH: “Everyone is fighting so hard to get on” – Pat Ryan on competitive camogie squads Predictions on the future of learning discussed at Limerick Lifelong Learning Festival last_img read more

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Joshua wants Pulev fight in UK

first_imgRelatedPosts Tyson Fury to Anthony Joshua: Don’t risk fighting Usyk Anthony Joshua, Okolie plot world title double Anthony Joshua wants Tyson Fury, Wilder fight Anthony Joshua will “almost certainly” defend his world heavyweight titles against Kubrat Pulev in Britain, says promoter Eddie Hearn. Britain’s unified champion has been granted more time for talks with Bulgarian Pulev, his IBF mandatory challenger, but the Matchroom Boxing boss is confident that terms will be agreed within a fortnight. Tottenham Hotspur Stadium and The Emirates, home of Arsenal FC, are on the list of possible locations in the UK, with a potential date in May or June. Almost certainly that will be AJ’s next fight and almost certainly in the UK. “It’s close and if it was proving difficult to make, we would go into purse bids now at this stage, or they would order it,” Hearn told Sky Sports. “We spoke to the camps and they basically said we need another two weeks and we’ll have it finalised. “Almost certainly that will be AJ’s next fight and almost certainly in the UK. “The main issue we have is Pulev wants to make as much money for that fight as he can. There isn’t as much money for that fight in the UK as there is elsewhere, but AJ has given me the instruction that I boxed in New York, I boxed in Saudi, I would like to do this one in the UK. “Spurs, Emirates, Cardiff, Twickenham, everywhere is in play, but most likely end of May, early June. Joshua-Pulev in the UK.”Tags: Anthony JoshuaEddie HearnKubrat PulevUKlast_img read more

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Confronting a stubborn system: The STEM pipeline for women engineers

first_imgGraphic by Jenny Chung | Daily TrojanJulianne Torres spent a Saturday in Redmond, Wash., dressed in business formal attire for an interview with Microsoft Corporation, one of the largest technology companies in the world.Torres, a senior studying computer science who is the president of the Society for Women Engineers, is no stranger to big industry names. She previously interned at Google and Intel.Torres attributes her success not only to her education, but also to inclusion networks and resource groups like the one she leads, which helped get her foot in the industry door. But, as she prepares to start her post-graduate career, Torres is braced to face the challenges of being a woman in STEM — namely an industry culture that can, to some, be alienating and exclusive.The Educational PipelineTorres said she did not consider pursuing engineering until her senior year of high school.“When I was growing up, I didn’t have that many STEM programs available,” Torres said. Yet, the academic opportunities for women in STEM, specifically engineers, is improving, according to statistics by the American Society for Engineering Education. The Viterbi School of Engineering’s 2017 freshman class profile indicated a record-breaking 44 percent of admitted students were female. But in 2016, only 20.8 percent of undergraduate engineering degrees in the United States went to women, while 79.2 went to men.While the national average of female engineering students stands at 19 percent, there have been increases in those numbers nationwide since the last recorded data in 2007, according to the ASEE.“In order to make an impact, we have to change everything in all categories,” Viterbi Dean Yannis Yortsos said. “You have to start from K through 12 schools — high school — then undergraduate schools, graduate schools.”Yortsos called this process the “pipeline process” — an increased focus on educational development for women and underrepresented minorities in the science, technology, engineering and math fields from a young age. He sees this as the solution for the STEM gender gap at USC, for both students and faculty.The institutional push to bring more women and minorities into STEM fields requires collaboration with educators to implement programs at a young age, Yortsos said. Some female engineering students like Torres, however, do not recall that focus in their high school classrooms.“My friends and I have said a lot at our SWE events, our outreach events, [that] we would have loved having this when we were younger,” Torres said. “The fact that they exist right now, I think, is a really good step in the right direction.”As president of SWE, Torres works to advocate for female empowerment in the engineering field by providing outreach activities to encourage the study of STEM among middle and high school students in the South Los Angeles community.Trina Gregory, a senior lecturer in information technology at Viterbi, received her bachelor’s degree in 1993 and recalled a drastically different workplace and University environment as a woman in tech.“I didn’t [have any support systems when I started],” Gregory said. “[I] went straight into being a software engineer in a very much male-dominated field … It definitely was that environment back then that the women were generally staff positions, like secretaries, those kind of administrative roles. And the engineers were usually male.”A Cultural ShiftData from the National Science Foundation suggests academic retention in STEM is promising, with an 8.2 percent increase in women receiving both master’s and doctorate degrees in engineering from 2004 to 2014.With the growth of organizations like Women in Computing, Girls in Tech and SWE, Gregory believes these resource groups provide increased support for students, leading to lower drop-off rates from the major.“When I first came here in 2007, there were still a lot of problems … with [female] retainment,” Gregory said of the computer science program.Yortsos also emphasized Viterbi’s mentorship integration for female and minority students. Several classes have involved a diverse representation of upperclassmen as teaching assistants for lower-level classes to foster academic growth and inclusion.In light of the controversy over a Google engineer’s memo about women in tech, as well as sexual harassment claims against Uber and Silicon Valley tech giants, Gregory believes the pipeline strategy is not enough to retain post-graduate women in the field without a change in company culture and in the perception of female engineers.Julianne Torres (left), president of the Society of Women Engineers, pictured at a networking dinner for SWE. Torres sees the organization as a supportive network for female engineers. Photo from USC Society of Women Engineers.“A big thing is trying to change the culture that exists,” Gregory said. “You can do all the diversity and inclusiveness [initiatives], but if your environment is the same as it’s always been, then the women aren’t going to stay.”Workplace retention numbers offer an image of the industry starkly different from increased academic inclusion.Thirty-nine percent of female engineers leave their jobs at the mid-level point, 10 to 20 years into their career, according to data from a report by The Center for Talent Innovation. Female engineers are also paid 82 percent of their male counterparts’ salaries, statistics from the 2013 U.S. Census Bureau’s American Community Survey revealed.The United States Department of Labor estimates there will be over 1.4 million total new computing-related job openings by 2018, when factoring in the industry’s growth and replacement needs.Torres will be one of many class of 2018 graduates seeking employment next spring; however, company culture and opportunities for growth in the ongoing STEM pipeline will play a role in determining her final decision, she said.“I do think culture is important and factors into the support you get and the resources at your disposal,” Torres said. “Even outside of having a diverse workplace, culture is something you really can’t change at your job.”last_img read more

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