VOA科学技术2024--Scientists Identify Building Blocks of Milky Way

Scientists Identify Building Blocks of Milky¹ Way

　　Researchers have identified two ancient star groupings that appear to be among the Milky Way Galaxy²'s earliest parts.

　　The structures are named after the Hindu gods Shakti and Shiva. They were discovered using observations from the European Space Agency's Gaia space telescope.

　　Scientists wrote in a study that the structures might be the remains³ of two galaxies⁴ that combined 12 billion years ago with the early pieces of the Milky Way. They said the discovery offers new information about how our galaxy formed.

　　Researchers said Shakti and Shiva are made up of stars that contain similar chemicals. They are believed to have formed 12 to 13 billion years ago. Each of the structures has a mass 10 million times greater than our sun.

　　Astronomer⁵ Khyati Malhan of the Max Planck Institute for Astronomy in Germany was the lead writer of the study. It was recently published in The Astrophysical Journal. Malhan said the study deals with a central question: "how do galaxies form in our universe?"

　　The Milky Way is a large spiral-shaped galaxy made up of hundreds of billions of stars. It is a large, flat circle about 100,000 light years across. A light year is the distance light travels in a year.

　　Malhan said the study might have identified the last event before the Milky Way began to take the shape it has today.

　　The European Space Agency launched Gaia in 2013. The space telescope is helping⁶ to create the largest and most complete three-dimensional map of the Milky Way. The telescope is measuring the positions, distances, and movements of the stars. This data permitted researchers to find Shakti and Shiva.

　　The researchers said Shiva and Shakti are now within 30,000 light years of the galaxy's center.

　　The study builds on another recent discovery. In 2022, scientists using Gaia data identified what they called the "poor old heart" of the Milky Way. It is made up of a population of stars from the earliest period of the galaxy found near its center.

　　The stars that make up Shiva and Shakti are different chemically from most of the Milky Way's other stars. They are called "metal poor" because of the amount of heavy elements they contain. For example, the stars have less iron, carbon, and oxygen than similar stars in other parts of the galaxy

　　Heavier elements first formed inside the universe's earliest population of stars. When these stars exploded at the end of their life cycles, the elements were then sent out into space.

　　Malhan said researchers would like to "trace the formation and evolution of the Milky Way starting from the beginning of it until present day." But he said this is difficult because the earliest period of the galaxy took place 11 to 12 billion years ago.

　　Scientists say the Big Bang event started the formation of the universe about 13.8 billion years ago.

　　Words in This Story

　　galaxy – n. any one of the very large groups of stars that make up the universe

　　spiral – n. a circular curving line that goes around a central point while getting closer to or farther away from it

　　three-dimensional – adj. having or seeming to have length, width, and depth

　　cycle – n. a set of events or actions that happen again and again in the same order

　　trace – v. to follow (something) back to its cause, beginning, or origin: to find out where something came from

　　evolution – n. a process of slow change and development

1 milky   

adj.牛奶的，多奶的；乳白色的

参考例句：

• Alexander always has milky coffee at lunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
• I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。

2 galaxy   

n.星系；银河系；一群(杰出或著名的人物)

参考例句：

• The earth is one of the planets in the Galaxy.地球是银河系中的星球之一。
• The company has a galaxy of talent.该公司拥有一批优秀的人才。

3 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

4 galaxies   

星系( galaxy的名词复数 )； 银河系； 一群（杰出或著名的人物）

参考例句：

• Quasars are the highly energetic cores of distant galaxies. 类星体是遥远星系的极为活跃的核心体。
• We still don't know how many galaxies there are in the universe. 我们还不知道宇宙中有多少个星系。

5 astronomer   

n.天文学家

参考例句：

• A new star attracted the notice of the astronomer.新发现的一颗星引起了那位天文学家的注意。
• He is reputed to have been a good astronomer.他以一个优秀的天文学者闻名于世。

6 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。