Researchers say the planet was likely destroyed long ago when it moved either too far from or too close to the star it once orbited.
The object is called ‘Oumuamua, which means "messenger from afar" in the native Hawaiian language. A report on the recent findings appears in the journal Nature Astronomy.
Artist's rendering of Oumuamua as it passed through the solar system after its discovery in October 2017. (Image Credit: European Southern Observatory/M. Kornmesser via NASA)
Scientists have been trying to understand more about ‘Oumuamua since its discovery in 2017. Some have even proposed it may be an alien spacecraft. In the recently published research, astronomers Yun Zhang and Douglas Lin said computer predictions suggest the object was a piece of a planet or planetary building block. The planet might have been torn apart by its star's "tidal forces."
‘Oumuamua is the first object from another star system found passing through our solar system. It is about 400 meters long. Its shape, strange way of moving and lack of dust and gases suggest it is not a normal comet or asteroid.
When a smaller body passes near a much bigger one, tidal forces created by the larger body can destroy the smaller one. This is what happened when comet Shoemaker–Levy 9 came too close to the planet Jupiter in 1992.
Zhang told the Reuters news agency that most planetary bodies are made of groups of rocks joined under the influence of gravity. In a way, they are similar to the sandcastles that children make at the beach, except that they are floating through space, Zhang said.
"Their structure can be disrupted when the force acting on the individual ‘sand particle' is larger than their mutual gravity," he added.
Zhang noted that ocean tides on Earth are affected in this way. Tides result from the gravitational pulls of the sun and moon. In space, a planetary body that comes close enough to a star falls victim to its strong gravitational pull.
Lin is an astrophysicist at the University of California, Santa Cruz. He said the star that destroyed ‘Oumuamua's home world probably was one-tenth to eight-tenths of the mass of our sun. Or it might have been a rare kind of cool and dense star called a white dwarf, Lin added.
The study suggests the existence of many objects formed this way.
"We show the possibility of panspermia carried by these objects," Zhang said. Panspermia is the hypothesized spread of microorganisms or chemicals that support life on objects moving through space.
‘Oumuamua is continuing on its path out of our solar system.
I'm Pete Musto.
Will Dunham reported on this story for the Reuters news agency. Pete Musto adapted it for VOA Learning English. Mario Ritter, Jr. was the editor. We want to hear from you. Write to us in the Comments Section.
奇怪的物体可能是一颗被撕裂的行星的遗骸
通过我们的长而细的对象移动太阳能SY 小号TEM可能是被拉开行星的残骸，科学家们说。
研究人员说，这颗行星很可能是在很久以前被摧毁的，当时它离它曾经运行的恒星太远或太近。
该对象称为“ Oumuamua”，在夏威夷语中表示“远方的信使”。关于最近发现的报告刊登 在“ 自然天文学 ” 杂志上。
在2017年10月发现Oumuamua通过太阳系后，艺术家对它的渲染。（图片来源：欧洲南方天文台/ M。Kornmesser，通过NASA）
自从2017年发现“ Oumuamua”以来，科学家一直在试图更多地了解它。有人甚至提议它可能是外星飞船。在最近发表的研究中，天文学家张云和林道格拉斯说，计算机预测表明，该物体是一块行星或行星构造块。该行星可能已被其恒星的“ 潮汐力 ” 撕裂了。
“ Oumuamua是另一个恒星系统的第一个物体，该恒星是通过我们的太阳系发现的。它长约400米。它的形状，奇怪的移动方式以及尘埃和气体的缺乏表明它不是正常的彗星或小行星。
当较小的物体靠近较大的物体时，较大物体产生的潮汐力会破坏较小的物体。这就是1992年Shoemaker–Levy 9彗星离木星太近时发生的情况。
张告诉路透社，大多数行星体都是由在重力影响下结合的岩石群组成的。张说，从某种意义上讲，它们类似于儿童在沙滩上制作的沙堡，只是它们漂浮在太空中。
他补充说：“ 当作用在单个'沙粒'上的力大于彼此的重力时，它们的结构可能会被破坏。”
张指出，地球上的海潮以这种方式受到影响。潮汐是由日月引力引起的。在太空中，一个足够接近恒星的行星体成为其强大引力的受害者。
林是加州大学圣克鲁斯分校的天体物理学家。他说，毁灭'Oumuamua的家园世界的恒星大概是我们太阳质量的十分之一到十分之八。林补充说，或者它可能是罕见的一种冷淡而密集的恒星，称为白矮星。
研究表明存在许多以这种方式形成的物体。
张说：“我们证明了这些物体可能导致泛精症。” 泛精子症是假设的微生物或化学物质传播，它们支持在空间中移动的物体上的生命。
