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cover of episode Is The Milky Way On A Collision Course?

Is The Milky Way On A Collision Course?

2025/7/2
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Short Wave
AI Deep Dive AI Chapters Transcript
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A
Arpit Arora
R
Regina Barber
Topics
Regina Barber: 过去一百年来，科学家们普遍认为仙女座星系注定要与银河系相撞，并在引力作用下相互吸引最终合并。然而，最近的研究表明，这种碰撞的可能性已经降至五五开。星系并非固体，而是主要由开放空间构成，其中包含着大量的恒星、气体、尘埃和暗物质。当两个盘状星系合并时，会形成类似球体的椭圆星系。 Arpit Arora: 星系合并是宇宙早期常见的现象，促成了今天我们看到的大型星系的形成。银河系在过去曾与多个星系发生过碰撞。暗物质驱动着星系间的碰撞，星系与其暗物质成分不断合并，形成了更大的星系系统。过去认为仙女座星系会与银河系碰撞的观点已经存在了数百年，但由于对星体运动测量的不确定性以及盖亚空间望远镜的出现，这一观点发生了改变。如果仙女座星系不与银河系合并，它们将永远围绕一个共同的质心进行宇宙舞蹈。如果它们真的相撞，夜空将会非常壮观，可能会形成更多的恒星，并最终形成一个巨大的椭圆星系。

Deep Dive

Chapters
A fun astronomy quiz to set the stage, starting with our closest planetary neighbors and expanding to our nearest star and galaxy. It leads to the main topic: Andromeda and its potential collision with the Milky Way.
  • Mars and Venus are Earth's nearest planetary neighbors.
  • Proxima Centauri is the closest star to our sun.
  • The Andromeda galaxy is the closest major galaxy to the Milky Way.

Shownotes Transcript

The Andromeda galaxy) lies just beyond (...OK, about 2.5 million light-years beyond) our galaxy, the Milky Way. For the past hundred years or so, scientists thought these galaxies existed in a long-term dance of doom — destined to crash into one another and combine into one big galactic soup. But today on the show, Regina) and computational astrophysicist Arpit Arora) explain why a recent paper out in the journal *Nature Astronomy *)suggests this cosmic game of bumper cars may never come to a head at all. *Interested in more space episodes? Email us your question at [email protected]).Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave).*Learn more about sponsor message choices: podcastchoices.com/adchoices)NPR Privacy Policy)