20 июля на конференции Particle Physics and Cosmology был сделан доклад, подводящий итоги работы WMAP. С августа 2001 года он раз за разом обозревал небо из точки L2 и вот теперь, 9 лет спустя, NASA официально объявит о завершении наблюдательной части проекта. В течении последующих месяцев аппарат будет выведен из точки L2 и либо уйдет на гелиоцентрическую орбиту, либо отправится к Луне, где под тщательным наблюдением LRO повторит подвиг LCROSS'a.
Так или иначе, это будет достойный конец достойной миссии, уже вписавшей себя в историю науки. Достаточно сказать, что 3 статьи с изложением основных результатов WMAP стали самыми цитируемыми за всю историю физики. С их популярным изложением можно ознакомиться здесь, а здесь можно почитать об истории и технологии исследования анизотропии реликтового излучения в целом.
Приведем также некоторые примечательные результаты WMAP в графическом виде
Итоговая карта анизотропии реликтового излучения с разрешением 0.2 градуса. Представляет собой суперпозицию разномасшабных флуктуаций со случайной фазой, которые (за небольшим исключением) укладываются в гауссово распределение.
Наибольшие отклонения от статистики наблюдаются на больших неоднородностях, в частности это большое "холодное пятно", природа которого не очень ясна. Также заслуживает внимания группа пятен, подозрительно напоминающая инициалы Стивена Хоукинга - "S H". Ученым еще предстоит разгадать эту загадку.
А это важнейший результат WMAP, энергетический спектр флуктуаций реликтового излучения. Вся карта неба раскладывается на сферические гармоники, порядковый номер которых (l) отложен по оси X. Масштаб флуктуации обратно пропорционален l, при этом l~100 соответствуют флуктуации угловым размером около 1 градуса. По оси Y отложена нормированная амплитуда флуктуаций. На графике видна серия максимумов, обусловленная наличием в ранней Вселенной акустических возмущений. По их величине определяется доля обычного (барионного) вещества и другие параметры общепринятой космологической модели.
Свой вклад в энергетический спектр также дают возмущения от первичных гравитационных волн и и тд, но точности WMAP не хватает для определения их характеристик. Как ожидается, исследованием всех этих вещей займется "Планк", обладающий втрое большим угловым разрешением и в 20 раз превосходящий WMAP по чувствительности. На рисунке выше приводится сравнение энергетического спектра глазами WMAP и "Планк".
Также заслуживает внимания группа пятен, подозрительно напоминающая инициалы Стивена Хоукинга - "S H". Ученым еще предстоит разгадать эту загадку.
Вот это ЗАГАДКА! Какая жуткая тайна!
А чуть ниже можно узреть силуэт самого С. Хоукинга, куда-то падающего. Должно быть, в чёрную дыру.
Вообще, исследовать солнечную систему автоматами - это примерно то же самое, что посылать робота вместо себя в фитнес, качаться.Зомби. Просто Зомби (с)
Выход из колыбели В БУДУЩЕМ может возникнуть только в случае конфликта цивилизаций. А. Семёнов (с)
WMAP finishes nine-year probe of infant universe[/size:421ece1986]
BY STEPHEN CLARK
Posted: October 6, 2010
The WMAP satellite devoted to studying the genesis of the universe has finished nine years of observations, but NASA will continue funding the mission for two more years so researchers can extract every bit of science from its ground-breaking observations.
Artist's concept of WMAP in space. Credit: NASA/WMAP science team
Launched in June 2001, the Wilkinson Microwave Anisotropy Probe collected its last science data Aug. 20 and fired thrusters Sept. 8 to leave its operational orbit.
WMAP was stationed about 930,000 miles from Earth at the L2 point, a gravitationally stable location where the tug of Earth's gravity keeps a spacecraft in lockstep with the planet as it orbits the sun. The L2 point is located on the side of Earth opposite the sun.
The spacecraft is now in a permanent parking orbit around the sun, according to a NASA statement releaesd Wednesday.
"We launched this mission in 2001, accomplished far more than our initial science objectives, and now the time has come for a responsible conclusion to the satellite's operations," said Charles Bennett, WMAP's principal investigator at Johns Hopkins University.
The spinning WMAP satellite scanned the sky to measure tiny variations in the temperature of the cosmic microwave background radiation 380,000 years after the Big Bang. Scientists consider the CMB the first light from the young universe after matter and light could exist independently as the universe cooled.
Only sensitive microwave space telescopes can detect the temperature fluctuations, which amount to just a millionth of a degree against an average backdrop of less than -450 degrees Fahrenheit. The measurements reveal warm and cool pockets in the infant universe, the distribution of energy before galaxies and stars began forming.
Among WMAP's accomplishments are the most accurate determination of the age of the universe at 13.75 billion years old, plus or minus 1 percent.
And WMAP confirmed normal atomic matter only makes up 4.6 percent of the material in the known universe. Dark matter, which has not been detected yet, makes up another 23 percent of the universe, while exotic dark energy comprises the remaining 72 percent.
The mission's ultimate legacy is still being written.
The science team will be on the job through 2012 analyzing the final two years of data gathered by WMAP. Only the first seven years of results have been processed so far.
"WMAP has opened a window into the earliest universe that we could scarcely imagine a generation ago," said Gary Hinshaw, the mission manager at NASA's Goddard Space Flight Center. "The team is still busy analyzing the complete nine-year set of data, which the scientific community eagerly awaits."
NASA approved the two-year post-operations phase after a panel of senior independent researchers recommended funding further processing of raw WMAP data and its public release.
"WMAP gave definitive measurements of the fundamental parameters of the universe," said Jaya Bapayee, WMAP program executive at NASA Headquarters. "Scientists will use this information for years to come in their quest to better understand the universe."
A European Space Agency mission named Planck carries instruments covering a frequency range 10 times greater than WMAP. Planck launched in 2009 finished the first of four planned sky surveys earlier this year.
Scientists say WMAP's measurements complement Planck and will continue to be useful in the future.
NASA's WMAP Science Team Awarded 2012 Gruber Cosmology Prize 06.22.12
NASA's Wilkinson Microwave Anisotropy Probe, known as WMAP, transformed the science of cosmology by establishing the age, geometry, and contents of the universe to astonishing precision. On June 20, the Gruber Foundation recognized this accomplishment by awarding its 2012 Cosmology Prize to WMAP principal investigator Charles L. Bennett at Johns Hopkins University in Baltimore and the science team he led.
"It is tremendously exciting to be recognized with the Gruber Cosmology Prize," said Bennett. "I have been very fortunate to work with the talented and fine people of the WMAP team, and I am particularly delighted that our entire science team has been honored with this prestigious award."
WMAP was launched June 2001 to make fundamental measurements in cosmology, the study of our universe as a while. WMAP was so successful, and its findings are now so widely accepted by the astronomical community, that it established the current foundation for our understanding of the universe, what astronomers call the "standard model" of cosmology.
WMAP achieved this success by scrutinizing the cosmic microwave background, the oldest light in the universe, emitted when the cosmos was just 378,000 years old. The mission was launched in June 2001 and acquired its final science data on Aug. 20, 2010. On Sept. 8, the satellite fired its thrusters, left its working orbit, and entered into a permanent parking orbit around the sun. The science analysis has continued, however, and team is now working toward the mission's fifth and final data release.
The latest analysis, released in 2011, shows that the universe is 13.75 billion years old, a figure accurate to within 1 percent. Only 4.6 percent of the combined matter and energy in the cosmos can be in forms we're familiar with, like atoms, planets and stars. The rest is dark matter (22.7 percent) and dark energy (72.8 percent), phenomena whose gravitational effects can be detected but which astronomers do not yet understand.
Additionally, WMAP data show that the universe must have flat geometry, to within 0.6 percent, and supports theories suggesting that the universe underwent an enormous growth spurt -- called "inflation" -- in the first trillionth of a trillionth of a trillionth of a second after the Big Bang.
"WMAP played a major role in turning cosmology into a precision science," said astrophysicist Alan Kogut, a WMAP team member at NASA's Goddard Space Flight Center in Greenbelt, Md., and one of the people who built the instrument. "It's now orbiting the sun, and aside from the scientific accomplishment, it's satisfying to know that something I helped put together will be around long after me."
This is the second time that Bennett has been honored by the Gruber Foundation. Its 2006 Cosmology Prize was awarded to John Mather at NASA Goddard and the Cosmic Background Explorer (COBE) team, of which Bennett was a member.
“Dr. Bennett’s discoveries have literally changed the scientific universe,” said John Mather, a principal investigator on COBE. For this work, Mather also received the 2006 Nobel Prize in Physics.
The annual Gruber Cosmology Prize recognizes "fundamental advances in our understanding of the universe" and is co-sponsored by the International Astronomical Union (IAU). Bennett and the 26-member WMAP team will share the $500,000 prize. Bennett will be presented with a gold medal at the IAU meeting Beijing in August.
December 21, 2012
FOR IMMEDIATE RELEASE
MEDIA CONTACT: Lisa De Nike
(443) 845-3148 (cell)
Since its launch in 2001, the Wilkinson Microwave Anisotropy Probe (WMAP) space mission has revolutionized our view of the universe, establishing a cosmological model that explains a widely diverse collection of astronomical observations. Led by Johns Hopkins astrophysicist Charles L. Bennett, the WMAP science team has determined, to a high degree of accuracy and precision, not only the age of the universe, but also the density of atoms; the density of all other non-atomic matter; the epoch when the first stars started to shine; the “lumpiness” of the universe, and how that “lumpiness” depends on scale size.
In short, when used alone (with no other measurements), WMAP observations have made our knowledge of those six parameters above about 68,000 times more precise, thereby converting cosmology fr om a field of often wild speculation to a precision science.
Now, two years after the probe “retired,” Bennett and the WMAP science team are releasing its final results, based on a full nine years of observations.
“It is almost miraculous, says Bennett, Alumni Centennial Professor of Physics and Astronomy and Johns Hopkins Gilman Scholar at the Johns Hopkins University’s Krieger School of Arts and Sciences. “The universe encoded its autobiography in the microwave patterns we observe across the whole sky. When we decoded it, the universe revealed its history and contents. It is stunning to see everything fall into place.”
WMAP’s “baby picture of the universe” maps the afterglow of the hot, young universe at a time when it was only 375,000 years old, when it was a tiny fraction of its current age of 13.77 billion years. The patterns in this baby picture were used to lim it what could have possibly happened earlier, and what happened in the billions of year since that early time. The (mis-named) “big bang” framework of cosmology, which posits that the young universe was hot and dense, and has been expanding and cooling ever since, is now solidly supported, according to WMAP.
WMAP observations also support an add-on to the big bang framework to account for the earliest moments of the universe. Called “inflation,” the theory says that the universe underwent a dramatic early period of expansion, growing by more than a trillion trillion-fold in less than a trillionth of a trillionth of a second. Tiny fluctuations were generated during this expansion that eventually grew to form galaxies.
Remarkably, WMAP’s precision measurement of the properties of the fluctuations has confirmed specific predictions of the simplest version of inflation: the fluctuations follow a bell curve with the same properties across the sky, and there are equal numbers of hot and cold spots on the map. WMAP also confirms the predictions that the amplitude of the variations in the density of the universe on big scales should be slightly larger than smaller scales, and that the universe should obey the rules of Euclidean geometry so the sum of the interior angles of a triangle add to 180 degrees.
Recently, Stephen Hawking commented in New Scientist that WMAP’s evidence for inflation was the most exciting development in physics during his career.
The universe comprises only 4.6 percent atoms. A much greater fraction, 24 percent of the universe, is a different kind of matter that has gravity but does not emit any light — called “dark matter”. The biggest fraction of the current composition of the universe, 71%, is a source of anti-gravity (sometimes called “dark energy”) that is driving an acceleration of the expansion of the universe.
“WMAP observations form the cornerstone of the standard model of cosmology, “says Gary F. Hinshaw of the University of British Columbia, who is part of the WMAP science team. “Other data are consistent and when combined we now know precise values for the history, composition, and geometry of the universe.”
WMAP has also provided the timing of epoch when the first stars began to shine, when the universe was about 400 million old. The upcoming James Webb Space Telescope is specifically designed to study that period that has added its signature to the WMAP observations.
WMAP launched on June 30, 2001 and maneuvered to its observing station near the “second Lagrange point” of the Earth-Sun system, a million miles from Earth in the direction opposite the sun. From there, WMAP scanned the heavens, mapping out tiny temperature fluctuations across the full sky. The first results were issued in February 2003, with major updates in 2005, 2007, 2009, 2011, and now this final release. The mission was sel ected by NASA in 1996, the result of an open competition held in 1995. It was confirmed for development in 1997 and was built and ready for launch only four years later, on-schedule and on-budget.
“The last word fr om WMAP marks the end of the beginning in our quest to understand the Universe,” comments fellow Johns Hopkins astrophysicist Adam G. Riess, whose discovery of dark energy led him to share the 2011 Nobel Prize in Physics. “WMAP has brought precision to cosmology and the Universe will never be the same.”
A video of Bennett discussing WMAP results: http://www.youtube.com/watch?v=72Y0mvXsHS0 Bennett’s webpage: http://cosmos.pha.jhu.edu/bennett/ Hinshaw’s webpage: http://www.phas.ubc.ca/users/gary-hinshaw Hawking on WMAP: http://www.newscientist.com/article/mg21628965.700-2013-smart-guide-new-maps-to-rein-in-cosmic-inflation.html
Johns Hopkins University news releases can be found on the World Wide Web at http://www.jhu.edu/news_info/news/ Information on automatic E-mail delivery of science and medical news releases is available at the same address.