Learn about the science behind the current exploration of the solar system in this free class. Use principles from physics, chemistry, biology, and geology to understand the latest from Mars, comprehend the outer solar system, ponder planets outside our solar system, and search for habitability in our neighborhood and beyond. This course is generally taught at an advanced level assuming a prior knowledge of undergraduate math and physics, but the majority of the concepts and lectures can be understood without these prerequisites. The quizzes and final exam are designed to make you think critically about the material you have learned rather than to simply make you memorize facts. The class is expected to be challenging but rewarding.
Lecture 4.21: All good things must come to an end
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Del curso dictado por Caltech
The Science of the Solar System
317 calificaciones
De la lección
Unit 4: Life in the solar system and beyond (week 2)
Conoce a los instructores
Mike BrownProfessor
Planetary Astronomy
Hey everybody, guess what?
We're done, this is the end of our class.
It's been nine weeks.
We have spent two, or three in the first case weeks on each of these four
important topics in the solar system.
Delving deeply to understand things about water on Mars, interiors of giant planets,
how you can use small bodies in the solar system to answer big questions, and
about looking for life in our solar system and outside of our solar system.
I hope what we've done is provided you with tools that you can now use
to understand when you see stories in the news about these topics and
other topics in the solar system.
And indeed even other topics in science, because we've not just given you
a collection of facts, things that you should know about Mars,
things that you should know about the interior of Europa.
What we've done, what we've tried to do,
is explain to you not only what we know but how we know, how we have
figured it out, how we are going to try to figure out more such things in the future.
And that, in the end is really the critical thing.
Understanding how planetary scientists go about the business of doing
planetary science, and how they understand the solar system, the galaxy around them.
We'll let you interpret, we'll let you make sense of all of these
discoveries that will clearly be happening in the decades to come.
What's going to be happening in decades to come?
Well on Mars, the Mars 2020 Rover is on its way It's not on its way,
it's being developed to go on its way to Mars to collect materials to eventually
bring them back to the Earth with the purpose there not of
understanding habitability but understanding inhabitation.
Curiosity Rover is still there making important discoveries.
There will be orbiters on Mars looking at the atmosphere,
trying to understand geochemical and biological processes.
The Juno Mission is on its way to Jupiter.
It's again, I think it's the one that's going to get the least press,
because it's hard to get people who don't really understand why it matters,
it's hard to get them excited about the interior of Jupiter.
And yet, as you now know, the interior of Jupiter is fascinating and important for
understanding the entire history and formation of the solar system.
But along with Jupiter itself, there will be many many discoveries still to be made
about giant planets around other stars that will be hot Jupiter.
They will be, I hope someday,
Jupiter found at the distance of Jupiter and with the circular orbits of Jupiter.
Right now we don't know of any of those.
When those are discovered then I will start to feel like I have found something
similar to our own solar system.
The small bodies and the missions to small bodies are always in the news.
The Dawn spacecraft is on its way to Ceres after it's just left Vesta.
And I have to tell you, I am really looking forward to seeing,
just seeing what Ceres looks like.
It's going to be a fascinating little world to study.
And of course new horizons is on it's way to go screaming past Pluto, and
I can't wait to see what that looks like.
I have to say though, scientifically I'm actually
much more interested not in Pluto but I'm interested in its moon Charon.
Its moon Charon is a little too small to have all those frosts that Pluto has on
it, which means that you'll be able to see the geology better.
You'll be able to see that impact record better, and
we'll get a better understand of what sorts of objects
are out there in the outer solar system from looking at the craters on Charon.
For small bodies though, I have to say that spacecraft are great, but
spacecraft will give you a detailed view of one small body at a time.
But really, as I think I've tried to give you the case.
The interesting things about the small bodies are not the individuals, but
it's the collection.
So the collections we will be continuing to study
with the biggest telescopes we have here on the ground.
And in the future with what is going to soon be my favorite new telescope,
it's the LSST.
Not a lame acronym large scale synoptic telescope.
The large scale synoptic telescope is an 8.4 meter telescope,
it's about the same as a super telescope in that the mirror size.
Its 8.4 meter telescope with what will be far an above the hugest camera
on a telescope in the world.
And it is designed to just take pictures of the sky night after night,
after night, covering the whole sky in something like five days going back and
doing it over again.
It will be the telescope that defines for many decades to come.
The small body populations of the inner and outer solar system.
It's going to be one of the most exciting telescopic projects that I
can think of coming up.
And finally, of course, life in the universe.
That's a little bit exciting too.
You're going to hear about things on Mars all the time.
Habitability on Mars perhaps, but eventually in the decades to come,
we will find out about inhabitation.
I think we will get samples back from Mars.
And we will be able to use our laboratory's here on the Earth
to really try to infer what's been going on there at Mars.
Europa there's a mission that is, perhaps in the planning stages of trying to
get to Europa to try to, sadly not land on the surface and drill down into the ocean.
But at least have those close flybys of Europa to really start to learn about
the conditions on the surface, and
really learn more about what the ocean is like on the inside.
Enceladus, Titan, they're kind of far away.
It may take a long time before we ever go back to those locations,
although Cassini is still there making beautiful measurements of them.
And of course, the inevitable I think is that we will start to get data
on the atmospheres of terrestrial planets around other stars.
And of all the things that might be discovered,
perhaps the most profound discovery that will be made is when
we find an atmosphere of a planet that really is something that we have a very
hard time explaining without the presence of some sort of biological processes.
Are there such planets out there?
Yes, I think they're out there.
Are they common?
Again, it's the same question I asked at the beginning.
Are they common?
I don't know.
Will there be one that's close enough that we can study it in detail?
I don't know.
Is life something that forms spontaneously,
easily on any sort of place that has a habitable environment?
We just don't know the answer to that question, and
this is a reason of course that we go out and explore.
I want to thank you for sticking with this crazy experiment of ours,
this entire nine weeks.
I hope you enjoyed it, I hope you learned something.
And I don't want to end this class without thanking some people.
This is the credits section of the class.
These videos that you have watched would not have ever made it into
their final form, or even their beginning form,
without the copious help of Caltech's Academic Media Technologies Office.
They have done a fantastic job that you guys have all benefited from.
Funding from the program came from the Vice Provost here at Caltech,
the Vice Provost for education who has believed in this project and
other online projects since the beginning, and has helped make them happen.
All of the online classes that Caltech has produced have
greatly benefited from the teaching and learning center here at Caltech.
I will say that I have enjoyed the opportunity to do this.
I thank you for sticking around.
If it weren't for all the people who are taking this class, it would not have
kept me going through the very difficult hours of recording all these lectures.
And I really hope that you will, from now on go outside at night and
look up at the sky, find those planets, find Jupiter, find Mars.
Look out at the stars, and really think about what's out there and know that you
now know some of the science of how we have learned what's really there, and
what more might be to come.
Thank you.
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