Recorded on May 15/16 this sequence of exposures follows the Full Moon during a total lunar eclipse as it arcs above treetops in the clearing skies of central Florida. A frame taken every 5 minutes by a digital camera shows the progression of the eclipse over three hours. The bright lunar disk grows dark and red as it glides through planet Earth's shadow. In fact, counting the central frames in the sequence measures the roughly 90 minute duration of the total phase of this eclipse. Around 270 BC, the Greek astronomer Aristarchus also measured the duration of total lunar eclipses, but probably without the benefit of digital watches and cameras. Still, using geometry he devised a simple and impressively accurate way to calculate the Moon's distance in terms of the radius of planet Earth, from the eclipse duration.?

記錄于5月15日至16日，這一系列曝光發(fā)生在月全食期間的滿月之后，當(dāng)時(shí)它在佛羅里達(dá)州中部晴朗的天空中的樹梢上方形成弧形。數(shù)碼相機(jī)每5分鐘拍攝一幀，顯示日食在三個(gè)小時(shí)內(nèi)的發(fā)展過程。明亮的月面在穿過行星地球的陰影時(shí)會變得暗紅色。事實(shí)上，計(jì)算序列中的中心幀可以測量這次日食整個(gè)階段大約90分鐘的持續(xù)時(shí)間。大約在公元前270年，希臘天文學(xué)家阿里斯塔丘斯（Aristarchus）也測量了月全食的持續(xù)時(shí)間，但可能沒有使用數(shù)字手表和相機(jī)。盡管如此，他還是利用幾何學(xué)設(shè)計(jì)了一種簡單而令人印象深刻的精確方法，從日食持續(xù)時(shí)間開始，根據(jù)行星地球的半徑計(jì)算月球的距離。