2020年火星冲

2020年10月6日

Mars Approach 2020
Image Credit: Jonathan T. Grayson

Explanation: Look to the east just after sunset tonight and you’ll see a most impressive Mars. Tonight, Mars will appear its biggest and brightest of the year, as Earth passes closer to the red planet than it has in over two years — and will be again for another two years. In a week, Mars will be almost as bright — but at opposition, meaning that it will be directly opposite the Sun. Due to the slightly oval shape of the orbits of Mars and Earth, closest approach and opposition occur on slightly different days. The featured image sequence shows how the angular size of Mars has grown during its approach over the past few months. Noticeably orange, Mars is now visible nearly all night long, reflecting more sunlight toward Earth than either Saturn or Jupiter. Even at its closest and largest, though, Mars will still appear over 100 times smaller, in diameter, than a full moon.

Tomorrow’s picture: flying bat squid

2020年火星冲
影像提供: Jonathan T. Grayson

说明: 在今晚日落后往东边看，可见到极为出采的火星。随着地球运行到2年多来（也是后续2年之中）最近火星的位置，今晚的火星是一年之中最大与最亮的一轮。在这个星期，明亮如斯的火星，会行进到与太阳180度反向的冲。因为火星和地球稍偏椭圆的轨道，每次火星冲的日期都略有变化。上面这幅时序主题影像，呈现在过去数个月里火星视大小的增长。目前彻夜可见色泽橙红的火星，向地球反射的阳光多于土星或木星，因此也比这二颗行星要亮。纵然位在冲拥有最大张角之时，火星的枧直径仍然不到满月的百分之一。

明日的图片: flying bat squid