 Every 26 months, the Earth overtakes Mars on the inside track as they both orbit the Sun.
Every 15 to 17 years, this happens when Mars is closest to the Sun. On 27 August this year they will pass at a distance of 55,760,000 km, closer than any time during the last 60,000 years. At its closest, Mars will be 25 seconds of arc in diameter, the size of a tennis ball at a distance of 528 metres. However, on the scale of the tennis ball, this approach is only 18 centimetres closer than in 1924, although 110 metres closer than in 2001.
Throughout July, August and September, Mars will be easy to see with the naked eye. Each night it will rise earlier, until by late August it will be just above the horizon, south of east, soon after sunset. Once risen, it will be the brightest object in the sky, appearing orange red. From the latitude of the UK, it will never rise higher than 22 degrees and you will need an unobstructed view to the south to see it. Mars will appear at its very best from the Southern Hemisphere, where by the middle of the night it will be high in the sky and its brightness and colour will make it very obvious. To see any surface detail requires a good quality telescope with a lens or mirror diameter of about 10 cm, on a stable mount. If you don't have one - and few people do - try to visit a public observatory or your local astronomical society. （Agencies） | 地球和火星都在各自的轨道围着太阳运转。每隔26个月，地球就要从内圈儿超过火星一次。 每隔15到17年，地球刚好在火星距离太阳最近的时候超过它。 今年8月27日，它们将再一次擦肩而过。届时二者相距5576万千米，这是6万年来最近的的一次。 在最近的地方，火星的直径是25弧秒，看上去跟528米以外的网球差不多大。 然而，以网球的比例来看，这次仅比1924年时靠近了18厘米，尽管比2001年近了110米。 在七、八、九三个月中，人们用肉眼就可以看到火星。每晚它升起的时间都会比前一天早一些，到八月底时，火星将在黄昏之后从地平线上升起，东偏南一点。 火星一升起来就将成为天空中最明亮的物体，呈橘红色。从英国所在的纬度上来观察，火星与地面的角度不会超过22度，人们需要在朝南的方向找个视野开阔的地方才能看到火星。 南半球是观察火星的最佳地点。午夜时分，它将高高地悬挂在天空中，它的光芒和色彩将使其分外耀眼。 要仔细观察火星表面，需要有一部镜头直径约10厘米的优质望远镜，架在固定底座上。不过有这种望远镜的人很少，如果你没有的话，那就去公共天文台或当地的天文协会吧。 second: 秒角度单位，相当于六十分之一度 （中国日报网站译） |
Updated: 2003-08-27 01:00
