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4 of the weirdest objects in space
The universe is filled with bizarre objects.
Then again, Earth is all we know. So what may seem wild and exotic to us is likely common throughout the cosmos. But that doesn’t take away from the fact that space is filled with many mysterious oddities that astronomers are just beginning to both discover and unravel.
So, without further ado, here is a list of just four (of many) contenders for the weirdest objects in space.
Weirdest objects in space: Black hole Sagittarius A*
Until recently, black holes seemed to come in only two sizes: either small remnants of collapsed stars or gargantuan beasts with masses of millions or even billions of suns. Only recently did astronomers confirm the existence of intermediate-mass black holes, but still, most black holes we observe are either petite or giant. An example of the latter sits at the center of every galaxy — including the Milky Way.
But while the supermassive black holes in many other galaxies radiate X-rays or violently spew huge jets of material, ours is strangely quiet. Too quiet, in fact, as if we’re hosting a sleeping monster.
Not that our galactic nucleus is a total mystery. While we cannot visually see what’s going on some 27,000 light-years away because it’s hidden behind impenetrable sheets of dusty gas, other wavelengths of light still leak out. Radio telescopes long ago detected an intense emission there, named Sagittarius A. The black hole, deeply buried within that radio noise, received the peculiar name Sagittarius A* or Sgr A*, which is pronounced “Sagittarius A-star.”
Sagittarius A* weighs about 4 million solar masses, which is less heavy than what lurks within the cores of most galaxies. Still, that much mass is impressively crammed into a spherical volume with a radius of less than 13 million miles (21 million kilometers) — half of Mercury’s orbit. As to the actual nature of this ultra-crushed singularity, or even whether some unknown process has halted its shrinkage and prevented it from attaining zero volume, no one knows. Our physics fails.
Weirdest objects in space: Pulsar planets
What was the first planet found beyond our solar system? Astro-geeks usually cite the discovery of the Jupiter-mass planet circling the naked-eye star 51 Pegasi in 1995. But the truth is far stranger. Three years earlier, astronomers Aleksander Wolszczan and Dale Frail announced they had found not one but two planets — and these orbited the oddest kind of star in the universe, a millisecond pulsar.
Its name is PSR B1257+12, and it lies in the constellation Virgo the Virgin at a distance of 980 light-years. It spins 161 times a second and, like all pulsars, is a neutron star, the smallest and densest visible object in the universe.
No telescope was used in the discovery, at least not one that gathers visible light. Instead, the huge Arecibo radio observatory in Puerto Rico, with its 1,000-foot (305 meters) collecting area, carefully monitored radio signals from pulsars. (Sadly, Arecibo Observatory recently catastrophically collapsed following two cable failures.)
Electromagnetic energy streaming away from their magnetic poles sweeps around like a lighthouse beam, producing radio flashes with each rotation. These super-collapsed neutron stars are always less than 20 miles (32 kilometers) wide, with wild amusement park spins of dozens or even hundreds of rotations per second.
Weirdest objects in space: Hoag’s Object
Galaxies are the largest things in the universe. Happily for us, they come in only a few varieties, making them easier to identify and theorize about. Nearly all are either elliptical (ball-shaped), irregular, or else spirals of various kinds. But a handful of oddballs fit none of these categories, and one galaxy stands all by itself.
In 1950, astronomer Arthur Hoag came upon a tiny, faint, 16th-magnitude ring surrounding a ball-like center, and reasonably assumed it was a planetary nebula — a nearby puff of gas expelled from a single old-aged star. However, later spectroscopic studies showed it was not. Hoag also thought it possible that this object was some sort of peculiar galaxy. And — as if to prove that if you make enough guesses, you increase your chance of success — his last surmise was right.
In 2002, the ultra-sharp optics of the Hubble Space Telescope revealed Hoag’s Object, as it is now called, as a perfect blue ring of stars, dust, and gas, complete with knotty clumps that are unresolved star clusters. In other words, yes, this is a galaxy. The problem, of course, is that Hoag’s Object does not assume the familiar spiral pattern, with arms wending their way inward to the older, yellower stars that make up nearly every galaxy’s nucleus. Instead, the nucleus sits all by itself in space. A whopping 70,000 light-years away from it, separated by near-nothingness, hovers that ring of billions of stars, planets, and who-knows what else.
Hoag’s Object lies 600 million light-years away from us in the constellation Serpens Caput, the rear half of the writhing snake held by Ophiuchus the Serpent Bearer. Its inner yellow core is 24,000 light-years across, almost the same as the core of our Milky Way. The outer ring of Hoag’s Object, with a width of 120,000 light-years, is similar in size to our galaxy’s diameter. It’s almost as if some malevolent alien starship vacuumed up the middle sections of a galaxy but bewilderingly spared both the center and the outermost regions.
Weirdest objects in space: Fermi bubbles
In November 2010, astronomers using NASA’s Fermi Gamma-ray Space Telescope announced an astonishing discovery. Emanating from the center of our Milky Way Galaxy are two bubbles made solely of powerful gamma rays.
This would have been strange enough if the bubbles, expanding at 2.2 million mph (3.5 million km/h), were concentric and centered on the galaxy’s core. But no, the two enormous spheres each hover in seemingly empty space above and below the black hole Sagittarius A* in the Milky Way’s nucleus. The bubbles are tangent to each other, touching at the galactic center to form a squat hourglass shape. The entire structure looks like the number 8 or a sideways infinity symbol.
With all the weird and wild objects in space, it’s impossible to pinpoint exactly which ones are the most bizarre. And thanks to astronomers’ tireless efforts, we’ll surely learn of even more exotic cosmic objects in the future — ones that could potentially shake up our understanding of the universe forever.
注释：
unravel: v
表示" 解开；阐明"，means "disentangle"，如：Police are trying to unravel the reason of their sudden disappearance.警察正在试图解释他们突然消失的原因。
ado: n
表示" 麻烦；忙乱；纷扰"，means "a rapid active commotion"，如：Without much ado, we set off. 我们出发的时候没有什么麻烦。
contender: n
表示" 竞争者"，means "the contestant you hope to defeat"，如：She is a strong contender for the team.她是入选队伍强有力的竞争者。
Gargantuan: adj
表示" 巨大的；庞大的"，means "of great mass; huge and bulky"，如：Convertibility of the currency is a gargantuan barrier. 货币的可兑换性就是一个巨大的障碍。
petite: adj
表示"（女子）娇小的"，means "very small"，如：Night after it left the poor bud, as a petite woman, but Moon. 一夜过后，它只剩下可怜的花苞，像一位娇小的女子，却又含苞待放。
spew: v
表示"涌出；呕吐；"，means "expel or eject (saliva or phlegm or sputum) from the mouth"，如：The volcano spewed molten lava. 火山喷出了熔岩。
galactic: adj
表示"星系的；银河系的"，means ""，如：The Milky Way is a galactic system made up of many fixed stars.银河系是由无数颗恒星组成的星际体系。
impenetrable: adj
表示" 不能穿过的；不可理喻的"，means "not admitting of penetration or passage into or through"，如：Armor plate is impenetrable by ordinary bullets. 装甲板普通子弹打不穿。
pulsar: n
表示" 脉冲星"，means "a degenerate neutron star;"，如：They discovered a new pulsar wake. 他们发现了一个新的脉冲星尾迹。
nebula: n
表示" [天]星云"，如：Fine dust in the nebula reflects the light. 星云中细致的尘埃反射了星光。
knotty: adj
表示"有结的；多节的；多瘤的"，means "highly complex or intricate and occasionally devious"，如：It is almost impossible to skirt the knotty problem.想回避这个棘手的问题几乎是不可能的。
clump: n
表示"丛；块；"，means "a compact mass"，如：I held a bit of the hearty earth in my hand to form a hard clump and added it to the bowl. 我用手捧起一点肥沃的土壤，并使其成为硬实的一整块，把它放进碗里。
wend: v
表示" 行；走；去"，means "direct one's course or way"，如：meet up with another writer and we wend our way through downtown. 我与另一位作家会合，慢慢蜿蜒穿过市中心。
writhe: v
表示" 挣扎；扭曲；翻腾；"，means "to move in a twisting or contorted motion, (especially when struggling)"，如：The more the worms writhe, the more I yearn to crush out their entrails. 虫子越受苦，我就越想碾碎它们。
malevolent: adj
表示"有恶意的；恶毒的"，means "having or exerting a malignant influence"，如：Unfortunately there are some malevolent people out there and it is best not to take undue risks. 不幸的是在外面的世界里有一些恶毒的人，最好不要过分去冒险招惹他们。
Emanate: v
表示" 散发；发出"，means "give out (breath or an odor);"，如：I wish I am a cup of tea, leave the misery in my heart and emanate the fragrance! 我愿意做茶，把枯涩留在心里，散发出来的都是清香。
tangent: adj
表示" 接触的；相切的；离题的"，means "ratio of the opposite to the adjacent side of a right-angled triangle"，如：It's not easy to follow her think because she's always go off at a tangent. 要跟上她的思路并非易事，因为她老是突然扯到题外去。
中文简要说明：
宇宙充满了怪奇的天体，但受制于地球是我们人类认知的基础。因此，对我们而言可能看似难以理解的事情，在宇宙中可能是很普遍的，天文学家们选出了下列4种特别奇怪的天体，并准备开始研究其中之谜。
据《天文学》（Astronomy）27日报导，这4种太空中最奇异的天体之一：人马座A*黑洞（Sagittarius A*黑洞）黑洞似乎只有2种大小：要么是恒星坍缩后的残骸，不然就是具有数百万甚至数十亿颗太阳质量的巨大怪物坐落在每个星系（Galaxy）的中心，包括银河系，到最近，天文学家才确认中等质量黑洞的存在，
但是，尽管其他星系中的超大质量黑洞会辐射X射线或猛烈喷发大量物质，但我们的黑洞却异常地安静。实际上，太安静了，仿佛一个沉睡的怪物。
尽管我们还是能观测银河系中心，但仍然看不穿尘埃、气体层所遮掩的地方，但其他波长仍然会泄漏出来，无线电望远镜很早就探测到那里的强烈发射源，一个深藏在无线电噪声中的黑洞，并将其被命名为人马座A*。
人马座A*的质量约为4百万太阳质量，比大多数星系中心的天体质量更轻。尽管如此，这么大的质量被压缩到半径不到2100万公里的球形中，仍然令人印象深刻——比水星轨道的一半还小。至于这种超压缩的奇异点的实际性质，甚至是是否有一些未知的过程，妨碍了它的收缩，使其无法达到「零」体积，没有人知道为什么，我们已知物理学失败了。
其二：脉冲星行星（Pulsar Planet）
天文学家沃尔什查尼（Aleksander Wolszczan）和弗雷尔（Dale Frail）宣布他们发现了「3颗行星」正围绕着宇宙中最奇特的恒星之一，毫秒脉冲星（a millisecond pulsar）公转。
这颗脉冲星的名字是PSR B1257+12，位于处女座（constellation Virgo），距离我们980光年远。它每秒旋转161次，就像所有脉冲星一样，是宇宙中最小且密度最高的的可见物体。具备305米收集面、位于波多黎各的阿雷西博无线电天文台（Arecibo radio observatory）仔细监测了来自这颗脉冲星的无线电信号。
它的磁极散发出去的电磁能量就像灯塔光束一样环绕，每旋转一次就会产生一次无线电闪光，这超级坍缩的中子星不到32公里宽，并以每秒数十圈甚至数百圈的速度疯狂旋转。但我们还不太了解为何旁边能有「3颗行星」围绕着它。
其三：霍格天体（Hoag's Object）星系是宇宙中最大的天体——星系，对我们来说，星系种类并不多，这使得它们更容易识别和理论化。几乎所有的星系都是椭圆形（球形）、不规则的，或者是各种形状的螺旋星系，但有几个怪胎不符合这些类别，而其中一个怪胎就是霍格天体。
2002年，哈伯太空望远镜捕捉到了霍格星系，星系不呈现熟悉的螺旋形状，螺旋臂向内弯曲。相反的，星系中心部位独自存在于太空中。所有的恒星都距离中央约7万光年，中间被虚无的东西分隔，外围则漂浮着数十亿颗恒星、行星和其他不可知之物。
霍格星系位于距离我们600百万光年的巨蛇座（constellation Serpens Caput）的内部黄色核心宽达2万4000光年，几乎与我们银河系的核心相同。霍格星系的外环，宽12万光年，与我们星系的直径相似，但这就像某个邪恶的外星飞船吸走了这一整个星系的中间部分，但令人困惑的是竟然保留了中心和最外围的区域。
其四：费米气泡（Fermi Bubble）
在2010年11月，天文学家使用NASA的费米伽马射线太空望远镜（NASA’s Fermi Gamma-ray Space Telescope）宣布了一个令人惊奇的发现。从我们银河系中心散发出来的是由强大的伽马射线组成的2个气泡。
这2个巨大的球体各自悬浮在星系核心的人马座A*上方和下方的太空中。这2个气泡相切，触及星系中心形成一个沙漏形状。整个结构看起来像数字8或一个横放的无穷符号。
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