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  • It seems like there's a new Earth-like planet making the headlines practically every month

  • these days.

  • And, well, we found another one!

  • But even though we've found a lot of new planets lately, astronomers have reason to

  • be especially excited about this one.

  • Most of the exoplanets we find are either thousands of light years away or positioned

  • in a way that makes them tough to studybut this one's in an almost perfect setup for

  • us to learn more about it.

  • Last week in the journal Nature, an international team of scientists announced they'd discovered

  • a new exoplanet called LHS 1140b, which orbits a red dwarf star only 40 light years away.

  • 1140b is special because it's relatively close to Earth and it transits, or passes

  • in front of, its star, which makes it much easier to study.

  • It was first discovered in 2014 as part of the MEarth Project, which searches for planets

  • around M dwarf stars, which are stars with less than 60% the mass of the Sun.

  • But it took another two years to confirm that the planet was really there.

  • So far, we know that 1140b is what's called a super Earth: a common type of planet bigger

  • than the Earth but smaller than Neptune.

  • Super Earths are often gas planets, but 1140b is pretty dense: it's more than six times

  • heavier than Earth, even though it's only about 1.4 times as wide.

  • So the planet is probably made of rock or metal instead of gas, and its gravity is strong

  • enough that it could have an atmosphere, too.

  • But life there would still be a lot different from home.

  • For one thing, I hope you like cake and ice cream, because you'd celebrate your birthday

  • around once an Earth month.

  • The planet orbits its star every 25 days, and it also gets ten times closer to its parent

  • star than Earth does to the Sun.

  • But the star is a red dwarf, which is much cooler and dimmer than the Sun, so even though

  • it's really close to its star, the planet actually gets less than half the light Earth

  • does.

  • That's not a whole lot of light, but it could be enough for liquid water to exist

  • on the planet's surface!

  • The star is also a lot more stable than many other red dwarfs, so it gives off much less

  • dangerous radiation.

  • Between its rocky surface, the amount of sunlight it gets, and the possible atmosphere, 1140b

  • would be a great place to look for signs of lifelike certain kinds of molecules in

  • its atmosphere.

  • Luckily for us, 1140b's orbit takes it between its star and Earth, which means we might be

  • able to learn more about its atmosphere based on the way light passes through it.

  • But astronomers won't be able to study that atmosphereor even confirm that it actually

  • existsuntil October, when 1140b passes in front of its star again.

  • So we'll have to wait until then to know more.

  • Meanwhile, much closer to home, the International Space Station might be getting a new neighbor!

  • The China Manned Space Program is hoping to build a space station by 2022, and last week,

  • they accomplished a major step in that project: they launched their first cargo ship.

  • The ship, called Tianzhou-1, launched aboard a Long March-7 Y2 rocket on April 20.

  • It's the latest in a series of successful missions:

  • Since 2003, when they sent their first astronauts to space, China's done a bunch of crewed

  • missions.

  • And in 2011, they launched Tiangong-1, a space laboratory that operated for four and a half

  • years.

  • That went well, so they did it again and launched another lab, Tiangong-2, last September, which

  • is still in orbit.

  • In October, two astronauts even lived and worked in the space lab for 33 days, completing

  • China's longest crewed mission so far.

  • These labs are much smaller than China's planned space station, but they've been an

  • important building block in getting ready for that next project.

  • Now, you can't really have a space station without being able to send up food and supplies,

  • so testing Tianzhou-1 in orbit is the next step.

  • They've already done more than 600 ground tests of the docking hardware, so the main

  • goal of this mission is to perform docking and refueling tests between the cargo ship

  • and the Tiangong-2 lab.

  • If all goes well, Tianzhou-1 will be able to use this docking technology to bring up

  • to 6000 kilograms of food and supplies to the future space station.

  • Once it's completed, the station will orbit 393 kilometers above the Earth, which is about

  • the same height as the ISS, which orbits at about 400 kilometers.

  • But just because the two stations will share the same traffic lane doesn't mean they'll

  • crash into each other: That's why we have orbital engineers.

  • China's space station will also be much smalleronly 60- to 70,000 kilograms,

  • which is about a sixth of the mass of the ISS.

  • But everyone has to start somewhere, and China has big plans for their future in space.

  • Who knows?

  • Maybe someday they'll visit our new planetary neighbor 1140b!

  • Thanks for watching this episode of SciShow Space News, and thanks to everyone who voted

  • for us in the Webby Awards!

  • SciShow won the People's Choice Webby for Science and Education, and we really appreciate

  • all of your support.

  • We love making this show, and we're so grateful to be a part of this supportive, passionate

  • community.

It seems like there's a new Earth-like planet making the headlines practically every month


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B1 中級 美國腔

中国几乎准备好建造他们的空间站(China's Almost Ready to Build Their Space Station)

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    joey joey 發佈於 2021 年 07 月 01 日