Most plants capture sunlight. And the results are usually green. Because in photosynthesis, plant chlorophyll uses [--1--] of blue and our sun’s abundant red, and reflects green. But what if—as many [--2--] suggest—there’s an Earth-like planet with multiple suns? Researchers at England’s University of Saint Andrews say that photosynthetic life on such a planet might end up as a [--3--] black or gray. Or even with a high SPF.

A quarter of all stars like our sun actually exist in multi-star systems. Plants on a planet with two sunlike stars could need protection against too much radiation—they might evolve their own [--4--] sunscreens.

Or a planet with two stars may have one sun-like star, along with a red dwarf star that’s also common in multi-star systems. Any photosynthetic life would be adapted to take advantage of the available light waves.

Plants that relied at times mostly on the dim red dwarf might need light from all across the visible [--5--]. They wouldn’t reflect any wavelengths, so they'd appear black. These ideas were presented at the current Royal Astronomical Society meeting. So for healthy eating on some other planets, try the leafy dark salad.
【视听版科学小组荣誉出品】
wavelengths sci-fi scenarios drab UV-blocking spectrum
披上"黑色外套"的地外植物 大多数植物在阳光的照射下, 吸收蓝光和红光波长,通过叶绿素进行光合作用, 并使叶子呈现绿色. 但是如果--就像科幻小说里写的那样--一个类地行星周边围绕着几个太阳, 又会是怎样一番光景呢? 英国圣安德鲁大学的研究人员表示,在这样的行星上, 植物的光合作用结果只会是呈单调的黑色或者灰色, 甚至是更深的颜色. [注1] 在聚星系[注2]中, 有四分之一的恒星与我们的太阳类似. 而有两颗太阳照射的行星上的植物则需要进化自身的紫外线阻挡层来保护自己抵挡过多的紫外线. 有的行星有两颗恒星, 但只有一颗类似太阳, 和聚星系中常见的红矮星在一起. 依赖光合作用的生物则利用可用光波来适应环境. 这种情况下的植物有时候会依赖昏暗的红矮星发出的大部分可见光波. 由于它们不会反射波长, 因此呈现黑色. 此项推测发表在当下的皇家天文协会的会议上. 如果有机会尝试地外行星上的植物, 不妨试试黑色沙拉吧~ 注1: 英国辐射防护委员会的一份研究报告指出，防晒作用最差的是浅黄色的棉织品，其防晒系数仅为 7 ，米色棉织品的防晒系数为 9 ，并且防晒系数随着颜色的加深而增大。 注2: 银河系中的星系多为单星系或双星系，具有三颗以上恒星的星系被称为聚星系，不太多见。