今年，天体物理学家们在多个方面取得了开创性成果。从在海上回收火箭，到发现宇宙中最极端事件，引力波，2016年科学领域的成就非同凡响。
以下内容就是本年度空间探索的亮点。
1.引力波
今年，最令人震撼的公告就是科学家们搜寻到了一阵时空的涟漪（在两个黑洞合并成型的时刻），这在科学界引起了巨大的波澜。利用“激光干涉引力波观测站”（LIGO）科学家们发现了引力波，这就像是用全新的眼睛去看宇宙。
引力波导致LIGO探测器的一条臂长变长的同时另一条臂长变短，能检测出引力波所引起的小于原子中心中质子直径千分之一尺度的变化量。相对来说，这就像测量距离最近的一颗恒星上，一根头发宽度的变化。
这一发现是历经一个世纪的探索，证实爱因斯坦最后的预测，引力波是真实存在的。它也让我们能够直接“看到”，之前看不到的对象：黑洞（并证实它的存在）。两个黑洞在13亿年前碰撞，引力波经过漫长的旅行，刚刚抵达了地球，就被LIGO探测到，这都为本次发现增添了神秘的色彩。
2. SpaceX完成首次海上火箭回收
SpaceX今年就有一个很不错的开端，把一颗卫星送入预定轨道，以这么低的成本发射火箭本身就是壮举了，他们还把火箭在海上回收了。这意味着火箭发射、着陆的单向过程，进入了低成本，可重复利用火箭的新阶段。
不幸的是，由于猎鹰9号在发射台爆炸，该公司宣布停止火箭发射，但是，有望在1月初重新启动。
艾伦•马斯克的远景规划是，建立一个火星城市，尽管这存在很多挑战，2016年对于SpaceX是大起大落的一年。
3.最近的恒星可能存在与地球类似的世界
比邻星是太阳最近的邻居，只有4光年的距离，它的太阳系里可能包含一个与地球类似的世界。直到今年，天文学家还没有确定，是否有行星围绕这颗恒星运转，更不用说找到我们有生之年可以拜访的、太阳系以外生命的港湾了。
伦敦玛丽皇后大学的研究团队发现了这颗行星，将其命名为"Proxima b"。利用比邻星的光，天文学家能够探测到恒星轨道的微妙变化（视为一个“摆动”），这是说明附近存在另一个巨大的天体。
但是比邻星的大小仅是太阳的10%，Proxima b的轨道周期也只有11天，这意味着它非常靠近恒星，就在所谓的宜居带上。后续无论是哈勃或是即将上任的詹姆斯 韦伯太空望远镜用来跟踪确定这颗行星上是否像地球一样适合生命，都是十分必要的。
4. 突破性的聆听计划和Starshot计划启动
Proxima b可能是地球的一个双胞胎，现在最大的挑战是如何在我们有生之年到达这里。突破性的计划starshot得到了俄罗斯亿万富翁尤里•米尔纳的资助和史蒂芬•霍金的赞同，nanosails可以被光束推进达到数百万公里每小时的速度。
这样的速度能够让宇宙飞船花20年左右的时间到达Proxima b，从而使人类首次向另一个已知行星发送信息。
但是目前还存在许多挑战，如这样的技术还不存在，与星际之间气体与尘埃的高速碰撞可能会在它达到目的地之前就被摧毁。
人类非常聪明，关键技术正以指数级的速度推进。到另一个星球旅行不再是科幻小说，而是一个雄心勃勃的科学项目。
也许，外星人已经以无线电传输的形式发出了他们自己的信息。另一个突破性的计划是聆听计划，也是由霍金倡导的，天文学家们正在距离我们最近的上百万颗恒星附近，寻找宜居带，来探测可能出现的无线电信号。包括澳大利亚自己的帕克斯射电望远镜（以及探测可见光的绿岸望远镜和利克天文台），整个2016年都在进行观测，搜索外星信号的任务将在未来十年持续进行。
5. 菲莱和罗塞塔团聚
2014年，菲莱成为首个登陆彗星的太空探测器，虽然它的着陆过程不顺利，导致数据传输中断。但最近它被罗塞塔发现，使得它能够继续进行彗星67P的分析工作。
菲莱登陆的地点及探测的方位，能够让天文学家们准确解释罗塞塔获取的，关于彗星组成的数据。
菲莱已经在岩石缝隙中生活了两年，罗塞塔一直在忙碌，拍摄了大量的图片，以及彗星的光谱和其它数据、
实际上，对罗塞塔分光计获取的数据进行分析，发现彗星挥发的成分中包含氨基酸、甘氨酸，由于日照加热变得不稳定，它们脱离彗星表面。甘氨酸是构成生命的基本组成；对于蛋白质和DNA都是必需的，这些已经确定的地球大气圈外的物质，对地球上的生命来说独一无二的，我们感谢彗星为我们微生物祖先提供了这些关键成分。
前景展望
2017年对于澳大利亚的天体物理学家来说，前景十分光明，卓越中心的：CAASTRO-3-D 研究宇宙时原子的构建；OzGRav利用引力波探索宇宙；以及SABRE，世界上第一个位于南半球的暗物质探测器，年底安装。
如果你认为2016是空间研究伟大的一年，那么请期待2017的精彩。（张微编译）
以下为英文原文：
The achievements of astrophysicists this year were as groundbreaking as they were varied. From reuniting a lander with a mothership on a comet, to seeing the most extreme cosmic events with gravitational waves, 2016 was truly out of this world for science.
Here are some of the highlights of the year that was.
1. Gravitational Waves
The spectacular announcement that ripples in the very fabric of spacetime itself had been found (and from surprisingly massive black holes colliding) sent similarly massive ripples through the scientific community. The discovery was made using the Laser Interferometer Gravitational-Wave Observatory (LIGO) and represents a fundamentally new sense with which to see the universe.
The gravitational waves cause one arm of the LIGO detector to stretch relative to the other by less than a thousandth of the width of a proton in the centre of the atom. Relatively speaking, that's like measuring a hair's-width change in the distance to the nearest star.
This discovery was the end of a century-long quest to prove Einstein's final prediction that these gravitational waves are real. It also allows us to directly "see" that famously and fundamentally invisible entity: the black hole (as well as definitively proving its existence). The fact that the two black holes collided 1.3 billion years ago and the waves swept through Earth just days after turning the detector on only add to the incredible story of this discovery.
2. SpaceX lands (and crashes) a rocket
The year started so well for SpaceX with the incredible achievement of sending a satellite into orbit, which is no mean feat itself at such low cost, before then landing that launch rocket on a barge in the ocean. A seemingly unstoppable sequence of launches and landings made it appear that a new era of vastly cheaper access to space through rockets that could be refuelled and reused was at hand.
Unfortunately, with the explosion of a Falcon 9 on the launchpad, the company was grounded, but apparently hopes for a resumed launch in early January.
Add to that the visionary plans to settle Mars outlined by Elon Musk, albeit not without some audacious challenges, and it's been a year of highs and lows for SpaceX.
3. Closest star may harbour Earth-like world
Proxima Centauri is our Sun's nearest neighbour at just over four light years away, and it appears that its solar system may contain an Earth-like world. Until this year, astronomers weren't even sure that any planets orbited the star, let alone ones that might harbour the best extrasolar candidate for life that spacecraft could visit within our lifetime.
The planet, creatively named "Proxima b", was discovered by a team of astronomers at Queen Mary University in London. Using the light of Proxima Centuari, the astronomers were able to detect subtle shifts in the star's orbit (seen as a "wobble"), which is the telltale sign that another massive object is nearby.
While Proxima Centuari is barely 10% the size of our Sun, Proxima b's orbit is only 11 days long, meaning it is very close to the star and lies just within the so-called habitable zone. However, follow-up with either Hubble or the upcoming James Webb Space telescope is necessary to determine if the exoplanet is as well suited for life as Earth.
4. Breakthrough Listen listening and Starshot star-ted
With a potential Earth twin identified in Proxima b, now the challenge is to reach it within a human lifetime. With the breakthrough initiative starshot, which has been funded by Russian billionaire Yuri Milner and endorsed by none other than Stephen Hawking, lightweight nanosails can be propelled by light beams to reach speeds up to millions of kilometres an hour.
Such speeds would allow a spacecraft to arrive at Proxima b in about 20 years, thus enabling humans to send information to another known planet for the first time.
However, there are many challenges ahead, such as the fact that the technology doesn't exist yet, and that high-speed collisions with gas and dust between stars may destroy it before it can reach its target.
But humans have proven to be resourceful, and key technology is advancing at an exponential rate. Incredibly the idea of sailing to another world is no longer science fiction, but rather an outrageously ambitious science project.
Perhaps, aliens are already sending out their own information in the form of radio transmissions. In another breakthrough initiative called Listen, also championed by Hawking, astronomers will be searching the habitable zones around the million closest stars to try to detect incoming radio transmissions. Involving Australia's very own Parkes telescope (as well as the Green Bank Telescope and Lick Observatory at visible wavelengths of light), observations have been running through 2016 and the search for alien signals will continue for the next decade.
5. Philae reunited with Rosetta
In 2014 the Philae lander became the first space probe to land on a comet, and even though its crash landing dictated that its science transmission would be a one-off, its recent rediscovery by Rosetta has allowed it to continue to contribute to analysis of comet 67P.
Philae's crash location, as well as the orientation of the doomed probe, has allowed astronomers to accurately interpret data taken by Rosetta regarding the composition of the comet.
While Philae has literally been living under (crashed on) a rock for the past two years, Rosetta has been the busy bee, taking numerous images, spectroscopy and other data of the comet.
In fact, data taken from Rosetta's spectrometer has been analysed and revealed that the amino acid, glycine, is present in the comet's outgassing, which breaks away from the surface of the comet as it becomes unstable from solar heating. Glycine is one of the fundamental building blocks of life; necessary for proteins and DNA, and its confirmed extraterrestrial confirms that the ingredients for life are unique to Earth, and that we may have comets to thank for providing our microbial ancestors with those crucial ingredients.
Outlook for Down Under
The future for astrophysics in Australia in 2017 looks particularly bright, with two ARC Centres of Excellence:CAASTRO-3-D studying the build of atoms over cosmic time; and OzGRav exploring the universe with gravitational waves; as well as SABRE, the world's first dark matter detector in the Southern Hemisphere, installed by end of the year.
If you thought 2016 was a great year in space, then you're in for a treat in 2017.
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