Anjali Tripathi: Why Earth may someday look like Mars
安贾莉·特里帕蒂: 为什么地球有朝一日可能会变成火星
Anjali Tripathi explores planets to uncover the processes that make and destroy them. Full bio
Double-click the English transcript below to play the video.
at the stars at night,
你看不见的部分,
is what you can't see,
or almost every star,
we tend to think of faraway things
我们倾向于想到远在天边、
大不相同的那些行星。
that are amazing about Earth
去寻找类似的星体。
to find things that are like that.
我们确实发现了惊人的现象。
we're finding amazing things.
关于地球的不可思议的事实,
about an amazing thing here on Earth.
and never coming back.
就不再返回。
as the Earth's atmosphere.
组成的一条细细的蓝线,
that form a thin blue line
the International Space Station,
这个气体薄层
from too many impacts,
或类似物质的撞击。
at least a little bit.
is not specific to planet Earth.
行星一词的部分含义,
to be a planet, if you ask me,
宇宙中的所有行星
but throughout the universe,
about planets themselves.
揭露了行星自身的奥秘。
about the solar system,
there are eight planets, maybe nine.
八颗行星,也可能是九颗。
who are stressed by this picture,
我们将冥王星加入了其中。
we're including Pluto.
and atmospheric escape,
around other stars that we can't see
其他恒星旋转的,
just stuck together
and have so much gravity.
is really at play here.
重力确实在发挥作用。
characteristic about planets
in the solar system are orbiting around.
atmospheric escape.
drive atmospheric escape from planets
行星大气逃逸的原因在于,
particles and light and heat
某个泰国节日的灯笼,
of lanterns in Thailand at a festival,
can propel gasses upward.
重力束缚的轻盈气体
and only bound by gravity,
causing atmospheric escape
between heating from the star
of gravity on the planet.
a minute for hydrogen
“动力探索者号”太空船完成。
of escaping hydrogen looks like,
样貌,如氧气和氮气,
like oxygen and nitrogen
that conclusively show us
被牢牢束缚于地球表面,
tightly bound to us here on Earth
reaching out far into space,
in undergoing atmospheric escape.
正在经历大气逃逸的星球,
is much smaller than Earth,
with which to hold on to its atmosphere.
它比地球的大气层薄得多。
than the Earth's.
这表明火星未曾有过可以阻止
that it didn't have an atmosphere
火星是一颗“红色行星”,
火星曾经比现在湿润,
Mars used to have a wetter past,
它就分解为氢气和氧气,
it broke up into hydrogen and oxygen,
it escaped into space,
rusty red color that we see.
大气逃逸可能曾经发生过。
probably happened,
正在利用太空探测器MAVEN探测火星,
at Mars called the MAVEN satellite,
is to study atmospheric escape.
挥发物演化”太空船。
and Volatile Evolution spacecraft.
shown pictures very similar
was losing its atmosphere,
我们可以看到,红色圆圈
you can see in the red circle
就是从火星上逃逸的氢气,
escaping away from the planet.
十多倍的距离之外,
the size of the planet,
不再受到火星引力的束缚,
no longer bound to that planet.
为什么火星是红色的。
from that lost hydrogen.
the only gas that's lost.
以及一些氧气和氮气,
and some oxygen and nitrogen,
观察从火星逃逸的氧气。
at the oxygen being lost from Mars.
that because oxygen is heavier,
away from the planet.
全部集中在红色圆圈里。
into that red circle.
atmospheric escape on our own planet
能看到大气逃逸,
在其他地方研究这一现象,
and send spacecraft
about the past of planets
can learn about the future
that we can't see.
before I go on to that,
我应该强调一点,
像这样的冥王星图片,
photos like this of Pluto,
is currently studying atmospheric escape
that I did want to talk about
恒星旋转的行星
that's not our Sun
or extrasolar planet.
at that star in the middle,
that are going past it all the time,
the light from the star
in the night sky
在银河系中探测到了
to detect over 5,000 planets
many more out there, like I mentioned.
在银河系外还有很多行星。
from these stars,
is not the planet itself,
a dimming of the light
decreases in front of the star,
that you saw before.
in different wavelengths.
紫外线来观察地球和火星。
and Mars in ultraviolet light.
观察凌日系外行星,
with the Hubble Space Telescope,
闪烁变得更明显,
much less light from the star,
an extended atmosphere of hydrogen
more of the light that you see.
we've actually been able to discover
大气逃逸的凌日系外行星。
that are undergoing atmospheric escape.
can be called hot Jupiters,
和木星一样,是气体行星,
they're gas planets like Jupiter,
lightweight gas that's ready to escape,
of atmospheric escape.
of hydrogen being lost on Earth,
pounds of hydrogen every minute.
does this make the planet cease to exist?
这会不会让行星不复存在?
that people wondered
closer to the Sun are rocky,
气态程度更高。
are bigger and more gaseous.
with something like Jupiter
with something like a hot Jupiter,
一开始像热木星一样,
with Mercury or the Earth.
would have gotten away
significantly impacted it
和一开始截然不同。
than what you started with.
with us here on Earth?
is going to become very intense.
就会变得非常强烈。
gas streaming off from a hot Jupiter,
流失气体的方式一样,
that is broken down,
into space more rapidly,
with this dry, reddish planet.
最近几十亿年内还不会发生,
for a few billion years,
to be aware of what's going on,
正在发生的事情:
is happening as we speak.
that you hear about happening in space
大家听说过很多
以便对那里的世界有更多了解。
to learn about these worlds.
or exoplanets like hot Jupiters,
像热木星这样的系外行星的同时,
about our planet here on Earth.
you think that space is far away.
不妨想想我今天的演讲。
ABOUT THE SPEAKER
Anjali Tripathi - AstrophysicistAnjali Tripathi explores planets to uncover the processes that make and destroy them.
Why you should listen
Even though Anjali Tripathi worked on NASA's Mars rovers in high school, the California native never expected to become an astronomer. Unlike the earthquakes she researched early on, astronomy seemed unconnected from daily life. As she has since discovered, exploring distant planets has a lot to do with life itself -- including the fate of the air we breathe. Using some of the most powerful telescopes and supercomputers, Tripathi studies how seemingly permanent planets change over time. She has pioneered the characterization of planet-forming environments and developed computer simulations to trace the 3D structure of planet atmospheres that are shrinking due to evaporation.
A natural teacher, Tripathi makes complex science concepts relevant and easy to understand. She believes that everyone can understand science -- even rocket science. She has partnered with the Smithsonian, Teach for America and others to increase scientific literacy and spread enthusiasm for the subject. Her engaging and humorous talks feature real world connections and unusual props, including a fully functioning Mars Pathfinder rover or full-size solar car.
Tripathi earned degrees in physics and astronomy from M.I.T., the University of Cambridge and Harvard University. Recognized as a promising American leader with a commitment to public service, Tripathi is a 2016-17 White House Fellow.
Anjali Tripathi | Speaker | TED.com