NASA称，遥远的“太空雪人”几乎没有陨石坑，也没有水

NASA称，遥远的“太空雪人”几乎没有陨石坑，也没有水

NASA’s space snowman is revealing fresh secrets from its home far beyond Pluto.

美国国家航空航天局(NASA)的“太空雪人”(space snowman)揭示了冥王星之外的新秘密。

More than a year after its close encounter with the snowman-shaped object, the New Horizons spacecraft is still sending back data from more than 4 billion miles away.

在与雪人形状的物体近距离接触一年多之后，新视野号宇宙飞船仍在从40多亿英里外发回数据。

“The data rate is painfully slow from so far away,” said Will Grundy of Lowell Observatory in Flagstaff, Arizona, one of the lead authors.

来自亚利桑那州弗拉格斯塔夫洛厄尔天文台的威尔·格伦迪是这项研究的主要作者之一。

Astronomers reported Thursday that this pristine, primordial cosmic body now called Arrokoth — the most distant object ever explored — is relatively smooth with far fewer craters than expected. It’s also entirely ultrared, or highly reflective, which is commonplace in the faraway Twilight Zone of our solar system known as the the Kuiper Belt.

天文学家星期四报告说，这个原始的宇宙天体现在被称为Arrokoth，是迄今为止被探索过的最远的天体，它的表面相对平坦，陨石坑比预期的要少得多。它也完全是红外线的，或者说是高反射的，这在我们太阳系遥远的边缘地带——柯伊伯带是很常见的。

Grundy said in an email that to the human eye, Arrokoth would look less red and more dark brown, sort of like molasses. The reddish color is indicative of organic molecules.

Grundy在一封电子邮件中说，在人眼看来，Arrokoth会少一些红色，多一些深褐色，有点像糖蜜。红色表示有机分子。

While frozen methane is present, no water has yet been found on the body, which is an estimated 22 miles long tip to tip. At a news conference Thursday in Seattle, New Horizons’ chief scientist Alan Stern of Southwest Research Institute said its size was roughly that of the city.

虽然有冰冻的甲烷存在，但球体上还没有发现水，估计从头到尾有22英里长。在周四于西雅图举行的新闻发布会上，新视野号的首席科学家、西南研究所的艾伦·斯特恩(Alan Stern)说，新视野号的大小与西雅图差不多。

As for the snowman shape, it’s not nearly as flat on the backside as previously thought. Neither the small nor big sphere is fully round, but far from the flatter pancake shape scientists reported a year ago. The research team likened the somewhat flattened spherical forms to the shape of M&Ms.

至于雪人的形状，它的背面并不像之前想象的那么平坦。小球体和大球体都不是完全圆的，但与科学家一年前报告的扁平的煎饼形状相去甚远。研究小组将这种有点扁平的球形形状比作m&m巧克力豆的形状。

No rings or satellites have been found. The light cratering suggests Arrokoth dates back to the formation of the solar system 4.5 billion years ago. It likely was created by a slow, gentle merger between two separate objects that possibly were an orbiting pair. The resulting fused body is considered a contact binary.

没有发现环或卫星。这些陨石坑表明，Arrokoth可以追溯到45亿年前太阳系的形成。它很可能是由两个独立的天体缓慢而温和地合并而成，它们可能是轨道上的一对。由此产生的融合体被认为是一个接触二元体。

This kind of slow-motion hookup likely arose from collapsing clouds in the solar nebula, as opposed to intense collisions theorized to form these planetesimals, or little orbiting bodies.

这种慢动作的连接很可能是由太阳星云的云的坍缩引起的，而不是理论上形成这些星子或小轨道天体的激烈碰撞。

The New Horizons scientists reported their latest findings at the annual meeting of the American Association for the Advancement of Science, as well as in three separate papers in the journal Science.

新视野号的科学家们在美国科学促进会的年会上报告了他们的最新发现，同时也在《科学》杂志上发表了三篇独立的论文。