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43 存在于恒星与行星间的黑色物质
DATE=5-2-01
TITLE=SCIENCE REPORT - Dark Matter
BYLINE=Jill Moss
(Start at 58")This is the VOA Special English Science Report.
When scientists look up into the night sky, they see stars, planets and the moon. There is also dark matter - the material between the stars and （1）planets. Scientists believe dark matter makes up much of the matter in our universe. However they have not been able to explain where it is. Although scientists have discovered signs of its (2) gravity, no one has been able to see dark matter - until now.
Recently a team of international scientists discovered observable dead stars -- or dark matter -- at the edge of our own Milky Way （3） galaxy. The experts announced their discovery in Science Magazine. They said they found thirty-eight （4）objects called "white dwarfs."
Each white dwarf is a burned up, dying star like the sun. However, each one has shrunk to about the size of Earth. These newly discovered white dwarfs are said to be about four- hundred- fifty light years from Earth. A light year is the distance that light travels in one year.
Ben （5）Oppenheimer led the research team that discovered the white dwarfs. He works at the University of California at Berkeley. He says the team-studied pictures of the white dwarfs taken during the past thirty years. The movement of the objects suggests that they are in the so-called "（6）halo" of the universe. This is a very large circular collection of stars and gas that surrounds our Milky Way galaxy.
This is important because the halo is much larger than the Milky Way galaxy itself. The researchers suggest that there are many white （7）dwarf stars throughout this halo. This discovery would explain much of the mass that cannot be found in our galaxy.
Mister Oppenheimer says most of the white dwarfs may be about ten- thousand- million years old. Scientists believe the universe was born about thirteen- thousand- million years ago after a huge explosion of matter called the Big Bang.
Scientists estimate that most of the dark matter in our universe is made up of unusual （8）particles. These particles do not contain （9）protons or （10）neutrons found in atoms. Scientists have not been able to identify these particles.
Some scientists are calling this discovery of observable dark matter historic. They say the findings raise many questions about how stars and our galaxy were formed. They also say the discovery opens the way for more study of some of the unexplained matter.
This VOA Special English Science Report was written by Jill Moss.
注释：
（1） planet[5plAnIt]n.[天]行星
（2） gravity[ 5^rAviti ]n.地心引力, 重力
（3） galaxy[ 5^AlEksi ]n.星系, 银河
（4） object[ 5CbdVikt ]n.物体, 目标, 对象
（5） Oppenheimer[ 5CpEnhaimE ]奥本海默Julius Robert, 1904-1967, 美国原子物理学家, 原子弹计划主持人
（6） halo[5heIlEJ]n.（日月周围的）晕轮, 光环, 荣光
（7） dwarf[ dwC:f ]n.矮子, 侏儒v.(使)变矮小
（8） particle[ 5pB:tikl ]n.粒子, 点, 极小量
（9） proton[ 5prEutCn ]n.[核]质子
（10） neutron[ 5nju:trCn ]n.中子
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