8.5. NASA Future Missions

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來自 University of Illinois at Urbana-Champaign 的課程

Emergence of Life

58 個評分

University of Illinois at Urbana-Champaign

Emergence of Life

58 個評分

How did life emerge on Earth? How have life and Earth co-evolved through geological time? Is life elsewhere in the universe? Take a look through the 4-billion-year history of life on Earth through the lens of the modern Tree of Life! This course will evaluate the entire history of life on Earth within the context of our cutting-edge understanding of the Tree of Life. This includes the pioneering work of Professor Carl Woese on the University of Illinois Urbana-Champaign campus which revolutionized our understanding with a new "Tree of Life." Other themes include: -Reconnaissance of ancient primordial life before the first cell evolved -The entire ~4-billion-year development of single- and multi-celled life through the lens of the Tree of Life -The influence of Earth system processes (meteor impacts, volcanoes, ice sheets) on shaping and structuring the Tree of Life This synthesis emphasizes the universality of the emergence of life as a prelude for the search for extraterrestrial life.

從本節課中

Week 8 - Astrobiology and the Search for Life in the Cosmos

No matter where you are or what you believe, sometime in your life you will look up into the sky and ask: What is out there? Where are we going? Is there life elsewhere in the universe? This course is dedicated to searching for answers to these questions. The fundamental concepts of life and habitable environments, established upon the modern synthesis of the Tree of Life, will direct us in recognizing biospheres that might be quite different from our own. In the last week of this course, we will look in detail at what the future has in store for space exploration and the search for life in the cosmos.

8.1. NASA Astrobiology: Roadmap to Life in the Universe11:44

8.2. NASA: A Platform for Inter-Disciplinary Science4:57

8.3. Mars Flybys and Orbiters: Getting the Picture8:37

8.4. Mars Rovers: Was the Red Planet Habitable?9:04

8.5. NASA Future Missions9:03

8.6. NASA Institute for Universal Biology8:59

8.7. Think and Wonder…Wonder and Think5:06

8.8. The Emergence of Life: Course Synthesis 6:33

Emergence of Life Outtakes3:58

與講師見面

Bruce W. Fouke, Ph.D.
Director of the Roy J. Carver Biotechnology Center
Department of Geology, Department of Microbiology, and Institute for Genomic Biology

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The US space missions to Mars have been extremely successful, and

been composed of a integrated series of flybys, orbiters, landers, and rovers.

This combination of robotics, that have been sent to Mars,

have provided us with a vast wealth of information,

everything from quantitative high resolution imaging of the topography, and

surface features on Mars, to the questions relating to water.

Was water previously present on Mars in great abundance on the surface, and

then, really going to the core question of habitability.

Has Mars in the past been a planet that had a habitable environment for

life itself, and therefore, once that gets established that water was present,

which it has been, then we start to delve into the questions moving from was Mars

a habitable planet to has life been present within that habitable environment.

And the answers are strongly going in the direction that, yes,

Mars has been in the past a habitable planet for life itself.

So, what we want to do now is just think a little bit about what Mars, mission

directors are putting together, for what the future holds for the red planet.

One of them is the MAVEN project, which is Mars Atmosphere,

and Volatile Evolution Mission.

And this is going to begin to do quantitative analysis from an orbiter

linked again to a lander that will look at these fundamental building blocks of

Carbon, and Hydrogen, and Oxygen, and what their distribution is, and

how they're possibly linked together, as molecules within the soils, and

the rocks of the planet.

The Curiosity Rover had the capability to do, shallow coring, but

some of these next generation rovers are going to be able to do deeper coring,

and the reason that's important to us is,

because the water reservoirs on Mars are no longer on the surface.

We think about four billion years ago due to meteor impacts, the atmosphere,

and the water were blown away by having a high frequency of meteor impacts

on the surface.

And therefore, the water reservoirs, and

hence therefore the capacity to have an ecosystem where life can get a foothold,

are going to be in the subsurface, and especially some of the deeper

shallow subsurface analyses are going to be important for that.

So the MAVEN mission is going to provide a lot of information regarding that, but

in 2016, there's going to be a large transition both in terms of

the rovers themselves, but in terms of the politics of doing space mission.

The European space agency is going to take the lead along with

the Russian confederacy to put up a rover,

orbiter combination that's called the ExoMars program, and that exomars orbiter,

and rover, they are again going to be able to collect even higher resolution images,

and chemistry, and analyses of the rocks.

And the minerals that are on the planet but

then they're also going to be able to do something that

we've been wanting to have happen a long time which is to drill deeper holes.

And, as you can see from this image,

the drill apparatus is a major part of the Rover,

it actually is almost the entire length of the Rover that hangs on the side of it,

and it's going to be able to drill down upwards of a meter into the subsurface.

So that's going to be a tremendous leap forward for understanding,

the habitability, and the distribution of potential microbial life on the planet.

Another important part of the future Mars missions that's

being discussed intensively right now, is putting humans on Mars, and

that human space mission, it carries a lot of interesting scenarios,

and intricacies with it that you might not think about.

First of all, it's upwards of a nine month journey each way, and so

that's an incredibly long period of time.

Another one is what should be the composition of the flight crew?

Should they all be male or all female?

Or some kind of a mixture, and then it really brings to

the fore the water that might be present on Mars is no longer on the surface.

So all the water sources would need to be brought from Earth at least for

the initial missions.

So not only sustaining energy, so the environmental conditions can be made.

So humans can be there, but also just, having a water source to sustain

the astronauts is a major part of that, and the ability to drill

very deep holes on the planet, and really get down into the frozen

cryosphere that's in the deep subsurface, that's going to require human beings.

So we can have a remote robot drill holes to some level, but the,

the very deep holes that go down upwards of 10s to 100s,

and deeper meters in the subsurface, will require the presence of human beings.

Another part of the future missions are the next generations of what the space

station labs are going to be able to hold, and these are important because,

all the missions that we were talking about, either on Earth,

or around the Moon, or on Mars, or other planets these are all linked together.

And even from the early stages the Mariner four was critically important for, on

Mars, for the Mariner five mission which went on to Venus, and so we've always had

this kind of piggybacking, which is interesting, between the various missions.

And even though one mission goes to one planet,

they help holistically with communications and staging for others, so

the space station, the next generations of that will be extremely important, as well.

And then one more avenue of NASA plans for the near future and

these are directly linked to Mars but also holistically throughout our solar system.

Is what they're calling the Asteroid Redirect project, and

that project is the idea that we could put up spacecraft that will be able to

directly sample, analyze, and in some cases, if the asteroid is small enough,

actually capture the asteroid, and you remember that the word asteroid means that

it's a body of rock, primarily rock that's moving through the solar system,

and so, there are many levels to this project.

One of them, if a smallish asteroid looks like it's going to hit the Earth,

and cause problems, we can go up, and be able to capture that asteroid,

but even more importantly, we think that the asteroid redirect capture project will

allow us to be able to have the asteroid sampled by humans.

So in this image, we can see that the spacecraft is powered by solar panels, but

has a large accordion kind of opening to it.

And the idea there is to move the space craft, so the according opening

goes toward the asteroid, and then rocket boosters are fired, and

then that asteroid is captured within the telescoping accordion,

and then once that's brought close, and stationary then astronauts can go up on

ladders, and actually physically chisel and hammer away on the asteroid itself.

And asteroids are really important to us, because first of all some,

of the basic building blocks of life, some of the amino acids that are required for

life, have been found already synthesized on some asteroids.

Another one, is that the minerals that are present on asteroids are precious metals

and other, are important natural resources that might be utilized.

And then of course, we have planetary protection, and the whole idea that, first

of all, can microbes can be transported on asteroids, which we think the answer is

yes, then another one is, will the asteroids then potentially hit the planet.

There's a whole variety of reasons why these missions are important, and viable.

The asteroid redirect project also brings to the table, for

the first time, other types of, a mechanisms for rocket boosters in space,

and this is an image of the xenon rocket booster, so, these are all

next generations ways to provide thrust for spacecraft in the future.

So the very successful Mars missions of the landers,

the flybys, the rovers, and the orbiter has provided us with

precisely the suite of information that we need about Mars, and

other planets to be able to move forward with this directive of

understanding what is the origin, and the distribution, and

composition in the future of life throughout our solar system.

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