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space-station-experiment-to-probe-origins-of-elements

探索元素起源的空间站实验

Space Station Experiment To Probe Origins of Elements

Astronomer Carl Sagan put it best: “We’re made of star stuff.” The atoms that make up the chemicals of our bodies didn’t originate on Earth; they came from deep space. The big bang created hydrogen, helium, and a little bit of lithium, but heavier atoms – the ones essential for life – came from processes related to stars.

“我们是由恒星组成的。”天文学家卡尔·萨根说得不错。构成我们身体化学物质的原子并非起源于地球;它们来自外太空。大爆炸创造了氢、氦和少量的锂,但更重的原子——生命所必需的原子——来自与恒星相关的过程。

Scientists can now probe deeper. Which kinds of stellar processes produce which elements? And which kinds of stars are involved?

科学家们现在可以进行更深的探测。什么样的恒星过程会产生什么样的元素?涉及哪些类型的恒星?

A new experiment called TIGERISS, envisioned for the International Space Station, aims to find out. TIGERISS has been chosen as the latest NASA Astrophysics Pioneers mission.

一项名为TIGERISS的新实验旨在为国际空间站找到答案。虎号被选为美国宇航局最新的天体物理学先驱任务。

Pioneers are small-scale astrophysics missions that enable innovative investigations into cosmic phenomena. They may include experiments designed to fly on small satellites, scientific balloons, the space station, and payloads that could orbit or land on the Moon.

先驱者是小型天体物理学任务,能够对宇宙现象进行创新的调查。它们可能包括设计在小型卫星、科学气球、空间站上飞行的实验,以及可以绕月飞行或在月球上着陆的有效载荷。

Earlier this year, the four previous Pioneers mission concepts, chosen in January 2021, were given the green light to move forward with construction and have been approved to fly later this decade.

今年早些时候,在2021年1月选定的四个先前的“先驱者”任务概念被批准推进建设,并已获准在本十年的晚些时候飞行。

“The Pioneer missions are an invaluable opportunity for early to mid-career scientists to conduct compelling astrophysics investigations, while gaining real experience in building space-based instrumentation,” said Mark Clampin, director of the astrophysics division at NASA Headquarters in Washington. “With TIGERISS, the Pioneers expand their reach to the space station, which offers a unique platform for exploring the universe.”

美国国家航空航天局华盛顿总部天体物理部门主任Mark Clampin说:“对于职业生涯早期到中期的科学家来说,‘先锋号’任务是一个非常宝贵的机会,可以进行引人注目的天体物理学研究,同时获得建造天基仪器的真正经验。”“通过TIGERISS,先驱者将触角延伸到了空间站,这为探索宇宙提供了一个独特的平台。”

TIGERISS Principal Investigator Brian Rauch, research associate professor of physics at Washington University in St. Louis, has been working on questions of elemental origins and high-energy particles since he was an undergraduate there. For nearly three years in college, Rauch worked on a particle detector called Trans-Iron Galactic Element Recorder, or TIGER. The experiment had its first flight on a balloon in 1995; long-duration balloon flights also launched a version of TIGER from Antarctica in 2001 to 2002 and 2003 to 2004.

TIGERISS的首席研究员Brian Rauch是圣路易斯华盛顿大学的物理学研究副教授,他从本科起就一直在研究元素起源和高能粒子的问题。大学期间,劳赫花了近三年的时间研究一种名为“跨铁银河元素记录器”(Trans-Iron Galactic Element Recorder,简称TIGER)的粒子探测器。1995年,该实验在气球上进行了首次飞行;在2001年到2002年以及2003年到2004年,长时间的气球飞行也曾在南极洲发射过一个TIGER版本。

As Rauch progressed in his research career, he helped TIGER evolve into the more sophisticated SuperTIGER. On Dec. 8, 2012, SuperTIGER launched from Antarctica on its first flight, cruising at an average altitude of 125,000 feet and setting a new record for longest scientific balloon flight — 55 days. SuperTIGER also flew for 32 days from December 2019 to January 2020. The experiment measured the abundance of elements on the periodic table up to barium, atomic number 56.

随着Rauch在他的研究生涯中的进步,他帮助TIGER进化成更复杂的超级虎。2012年12月8日,“超级虎”号从南极洲发射,进行了首次飞行,在平均12.5万英尺的高度巡航,创造了科学气球飞行时间最长的新纪录——55天。“超级虎”还从2019年12月到2020年1月飞行了32天。该实验测量了元素周期表中直到钡(原子序数56)的元素的丰度。

On the International Space Station, the TIGER instrument family will soar to new heights. Without the interference from Earth’s atmosphere, the TIGERISS experiment will make higher-resolution measurements and pick up heavy particles that wouldn’t be possible from a scientific balloon. A perch on the space station will also allow for a larger physical experiment – 3.2 feet (1 meter) on a side – than could fit on a small satellite, increasing the potential size of the detector. And the experiment could last more than a year, compared to less than two months on a balloon flight. Researchers plan to be able to measure individual elements as heavy as lead, atomic number 82.

在国际空间站上,虎式仪器系列将飞向新的高度。如果没有地球大气层的干扰,TIGERISS实验将进行更高分辨率的测量,并捕获科学气球无法捕获的重粒子。空间站上的栖木也将允许进行更大的物理实验——一侧3.2英尺(1米)——这比小型卫星能容纳的更大,增加了探测器的潜在尺寸。这个实验可以持续一年多,而气球飞行不到两个月。研究人员计划能够测量单个元素,如原子序数为82的铅。

Star Stuff

那些有关星星的东西

All stars exist in a delicate balance – they need to put out enough energy to counteract their own gravity. That energy comes from fusing elements together to make heavier ones, including carbon, nitrogen, and oxygen, which are important for life as we know it. But once a giant star tries to fuse iron atoms, the reaction doesn’t generate enough power to fight gravity, and the star’s core collapses.

所有的恒星都存在于一种微妙的平衡中——它们需要放出足够的能量来抵消自身的引力。这种能量来自于将元素融合在一起,产生更重的元素,包括碳、氮和氧,正如我们所知,这些元素对生命非常重要。但是,一旦一颗巨大的恒星试图融合铁原子,这个反应就不会产生足够的能量来对抗重力,恒星的核心就会坍塌。

This triggers an explosion known as a supernova, in which shock waves cast out all of those heavy elements that had been made in the star’s core. The explosion itself also creates heavy elements and accelerates them to nearly the speed of light – particles that scientists dub “cosmic rays.”

这就引发了超新星爆炸,冲击波将恒星核心中形成的重元素全部释放出来。爆炸本身也会产生重元素,并将它们加速到接近光速的速度——科学家称之为“宇宙射线”的粒子。

But that’s not the only way heavy atoms can form. When a superdense remnant of a supernova called a neutron star collides with another neutron star, their cataclysmic merger also creates heavy elements.

但这并不是形成重原子的唯一方式。当被称为中子星的超新星的超高密度残骸与另一颗中子星相撞时,它们的灾难性合并也会产生重元素。

Read more at Nasa.gov

NASA官网上阅读更多

图片出处

STARSET_Mirror