Astronomy Picture of the Day

Explanation: Q: What was made by humans and is 6.5 billion miles away? A: Pioneer 10 - and last year was the 25th anniversary of its launch. More than 9.5 light-hours distant, Pioneer 10 is presently about twice as far from the Sun as Pluto, bound for interstellar space at 28,000 miles per hour. The distinction of being the first human artifact to venture beyond the Solar System is just one in a long list of firsts for this spacefaring ambassador, including; the first spacecraft to travel through the asteroid belt and explore the outer Solar System, the first spacecraft to visit Jupiter, the first to use a planet's gravity to change its course and to reach solar-system-escape velocity, and the first spacecraft to pass beyond the known planets. Pioneer 10's mission is nearing an end - now exploring the distant reaches of the heliosphere it will soon run out of sufficient electrical power to operate science instruments. However, the 570 lb. spacecraft will continue to coast and in 30,000 years or so it will pass within about 3 light years of a nearby star known as Ross 248. Ross 248 is a faint red dwarf just over 10 light years distant in the constellation Taurus. (Note: This year Voyager 1, launched 21 years ago but traveling faster than Pioneer 10, became humanity's most distant spacecraft.)

請問：什麼東西是由人類製造的，而且在104億公里之外？ 答案是先鋒者10號，去年是它發射的25周年。 距離超過9.5光時的先鋒者10號，目前離太陽的距離約為冥王星的兩倍，以每小時45,000公里的速度向星際空間曳航。 預計它會是第一個航行到太陽系外頭的人類工藝品，而這只是這位太空大使的眾多"第一"之一，它的成就包括：第一個穿越小行星帶及探索太陽系外圍的太空船，第一艘造訪木星的太空船，第一個利用行星的重力改變其航道以達到太陽系脫離速度的太空船，及第一艘航行到已知行星後方的太空船。 先鋒者10號的任務已接近尾聲；目前正在探索日球層邊界的它，很快就會缺乏足夠的電力來操作科學儀器。 然而，這個重達260公斤的太空船將繼續曳，再過3萬年左右，它將以大約3光年的間距掠過名為Ross 248的鄰近恒星。 Ross 248是一顆位在金牛座方向約10多光年遠處的昏暗紅矮星。 (注：在21年前發射的旅行者1號，因為航速比度比先鋒者10號快，在今年會成為人類最遙遠的太空船）。