黑色大理石──地球夜間新面貌
林光餘譯
美國航太署及海洋大氣署衛星顯示了地球夜間新面貌。科學家揭開前所未見的地球夜間新面貌：他們以一顆新的美國航太署與海洋大氣署的衛星，利用無雲的黑夜攝製地球的合成圖像。圖像空前精細，顯示了整個地球的自然光與人為光景象。
NASA-NOAA Satellite Reveals New Views of Earth at Night
Scientists unveiled today an unprecedented new look at our planet at night. A global composite image, constructed using cloud-free night images from a new NASA and National Oceanic and Atmospheric Administration (NOAA) satellite, shows the glow of natural and human-built phenomena across the planet in greater detail than ever before.
這是根據「蘇奧米國家極軌合作衛星」的探測數據所組合成的地球新面貌以及世界各地城市燈光動畫圖。這批衛星探測數據分別從2012年4月間的九天中，以及同年10月間的十三天中取得。(譯注：下文簡稱「蘇奧米國家極軌合作衛星」為「蘇奧米衛星」。該衛星係為紀念氣象學家福爾納‧蘇奧米Verner E. Suomi而命名。)
This new global view and animation of Earth’s city lights is a composite assembled from data acquired by the Suomi NPP satellite. The data was acquired over nine days in April 2012 and 13 days in October 2012. It took 312 orbits to get a clear shot of every parcel of Earth's land surface and islands.
畫面提供：航太署地球天文台/海洋大氣署 地球物理數據中心
許多衛星僅能利用日間的充分陽光來觀察地球，但自從去年發射安裝有新型感應器的航太署與海洋大氣署極軌合作衛星之後，科學家現在可以觀測地球大氣與表面的夜間情形。
Many satellites are equipped to look at Earth during the day, when they can observe our planet fully illuminated by the sun. With a new sensor aboard the NASA-NOAA Suomi National Polar-orbiting Partnership (NPP) satellite launched last year, scientists now can observe Earth's atmosphere and surface during nighttime hours.
這種新型感應器，即「可見紅外光影像輻射儀」(the Visible Infrared Imaging Radiometer Suite, VIIRS)的晝夜波段(day-night band)的感應性能敏銳，足以探測地球大氣所產生的夜光以及在海面獨行船隻的光線。雖然美國國防氣象衛星計畫下的衛星群已使用低光度感應器達四十年之久，不過紅外光影像輻射儀晝夜波段所探測到的地球夜光解析效果卻比軍方氣象衛星好。
The new sensor, the day-night band of the Visible Infrared Imaging Radiometer Suite (VIIRS), is sensitive enough to detect the nocturnal glow produced by Earth's atmosphere and the light from a single ship in the sea. Satellites in the U.S. Defense Meteorological Satellite Program have been making observations with low-light sensors for 40 years. But the VIIRS day-night band can better detect and resolve Earth's night lights.
這是美國本土的夜間影像，是利用蘇奧米衛星於2012年4月與10月間所獲得的數據組合而成。影像是由衛星的「可見紅外光影像輻射儀」的晝夜波段所攝製。這套可見紅外光影像輻 射儀可以探索從綠至近紅外線光波範圍的光，並且可使用濾光技術來觀察像城市燈光、天然氣火焰、極光、野火以及月光折射等微弱光源。
This image of the continental United States at night is a composite assembled from data acquired by the Suomi NPP satellite in April and October 2012. The image was made possible by the satellite's "day-night band" of the Visible Infrared Imaging Radiometer Suite (VIIRS), which detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe dim signals such as city lights, gas flares, auroras, wildfires and reflected moonlight.
畫面提供：航太署地球天文台/海洋大氣署 地球物理數據中心
史蒂夫‧米勒(Steve Miller)是航太署與海洋大氣署科羅拉多州立大學大氣研究合作學院的研究員；他說，我們的確有無數理由需要在日間觀察地球，但我們也需要觀察黑夜中的地球，「地球不像人類，它從不睡覺。」
"For all the reasons that we need to see Earth during the day, we also need to see Earth at night," said Steve Miller, a researcher at NOAA's Colorado State University Cooperative Institute for Research in the Atmosphere. "Unlike humans, the Earth never sleeps."
請點擊making landfall over New Jersey，您所看的這一張是在10月29日以晝夜波段，利用月光觀察颶風珊蒂在新澤西州登陸時的照片。這些夜間影像顯示暴風雨讓廣大地區無數民眾陷於黑暗的大停電。可見紅外光影像輻射儀的夜間影像功能，可以探測到比前更完整的暴風雨情景以及其他氣象狀況，諸如利用紅外線或熱感應器很難觀察的霧靄。夜間也是許多雲層成形之始。
The day-night band observed Hurricane Sandy, illuminated by moonlight, making landfall over New Jersey on the evening of Oct. 29. Night images showed the widespread power outages that left millions in darkness in the wake of the storm. With its night view, VIIRS is able to detect a more complete view of storms and other weather conditions, such as fog, that are difficult to discern with infrared, or thermal, sensors. Night is also when many types of clouds begin to form.
這是蘇奧米衛星上的可見紅外光影像輻射儀於2012年10月13日捕捉到尼羅河流域及其三角洲的夜間圖像。
On Oct. 13, 2012, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this nighttime view of the Nile River Valley and Delta.
Credit: NASA Earth Observatory/Suomi NPP
畫面提供：航太署地球天文台/ 蘇奧米衛星
「國家海洋大氣署的國家天氣中心正不斷利用晝夜波段進行探索，」國家海洋氣象署聯合極軌衛星系統(NOAA's Joint Polar Satellite System)的計畫科學家密區‧哥德堡(Mitch Goldberg)說道，「可見紅外光影像輻射儀的超高解析度數據，使夜間天氣預測層次大幅提升。」
"NOAA's National Weather Service is continuing to explore the use of the day-night band," said Mitch Goldberg, program scientist for NOAA's Joint Polar Satellite System. "The very high resolution from VIIRS data will take forecasting weather events at night to a much higher level."
不像一般照相機捕捉畫面時僅需一次曝光；晝夜波段對某一景像則以連續掃描方式產生畫面，並將之分解為無數單獨畫素。然後晝夜波段檢視每一畫素中的光量。如果非常明亮，儀器中的低增益模式(low-gain mode)會啟動，以防止畫素不至過於飽和；如果畫素光量過暗，信號就會放大。
Unlike a camera that captures a picture in one exposure, the day-night band produces an image by repeatedly scanning a scene and resolving it as millions of individual pixels. Then, the day-night band reviews the amount of light in each pixel. If it is very bright, a low-gain mode prevents the pixel from oversaturating. If the pixel is very dark, the signal is amplified.
這是根據蘇奧米衛星於2012年10月4月與10間的數據，加以組合而成的世界地圖。
Composite map of the world assembled from data acquired by the Suomi NPP satellite in April and October 2012.
畫面提供：航太署地球天文台/海洋大氣署 地球物理數據中心
這張新的地球夜景高解析度合成圖像，是在舊金山美國地球科學聯盟的記者招待會上發表的。這張照片以及其他使用可見紅外光影像輻射儀晝夜波段所拍攝的照片，正為研究者提供許多前所未見或不易認定的有價值資訊。
The new, higher resolution composite image of Earth at night was released at a news conference at the American Geophysical Union meeting in San Francisco. This and other VIIRS day-night band images are providing researchers with valuable data for a wide variety of previously unseen or poorly seen events.
米勒說，這就像是有三台低光度照相機在同時運作，我們依據景象中的不同狀況，選用其中最佳一台的畫面。蘇奧米衛星能夠在有月光或無月光下運作，攝取清晰的地球大氣、陸地與海洋表面景像。(Flickr網站存有更多幻燈播放模式的蘇奧米衛星《黑夜中地球》圖集。http://www.flickr.com/photos/gsfc/sets/72157632175125121/)
"It's like having three simultaneous low-light cameras operating at once and we pick the best of various cameras, depending on where we're looking in the scene," Miller said. The instrument can capture images on nights with or without moonlight, producing crisp views of Earth's atmosphere, land and ocean surfaces.
「夜間不再如我們想像那麼黑暗，」米勒說道。由於科學家藉著可見紅外光影像輻射儀晝夜波段從夜間自然光與人為光中取得資訊，「我們不必再面對黑暗了。」
"The night is nowhere as dark as we might think," Miller said. And with the VIIRS day-night band helping scientists to tease out information from human and natural sources of nighttime light, "we don't have to be in the dark anymore, either."
航太署哥達太空飛行中心的蘇奧米計畫科學家詹姆斯‧葛利森(James Gleason )則說，「這些從蘇奧米衛星取得的驚人晝夜波段畫面；它不但震驚科學界，而且超過我們事前的預計。」
"The remarkable day-night band images from Suomi NPP have impressed the scientific community and exceeded our pre-launch expectations," said James Gleason, Suomi NPP project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.
在日光下，我們龐大如大理石般光潔的地球畫面，包含了所有陸地、海洋與雲層。不過在夜間卻是電光景象。這個影片提供一個由新蘇奧米衛星「可見紅外光影像輻射儀」攝製的地球夜間景象精彩畫面的敘述旅程。
note: Here is a beautiful clip of some astronauts sharing their blissful experiences of earth overview from the space. http://www.upworthy.com/some-strange-things-are-happening-to-astronauts-returning-to-earth?g=2