Martian Design Challenge Webchat
November 20, 2003
Chat with NASA
scientists to ask questions about human habitability on Mars, and possibly
life-forms that might survive in the Martian environment.
More
information on this event is available
Read bios of experts Geoff
Briggs and Jon
Rask (.pdf
format)
Thurs Nov 20
[ Linda/NASAQuest
- 31 - 08:35:04 ]
Join us here on November 20, 2003 to chat about information that will help
you refine your Martian designs. Our experts would be happy to answer your
questions. In the meantime, make sure to check with your fellow designers
in the forum at: http://archimedes.arc.nasa.gov/questchat/chatroom8/main/chat.cgi
[ Linda/NASAQuest - 40
- 08:46:22 ]
During the last chat we had more than 400 questions. We try to choose
carefully and ask well-thought-out questions of general interest. Thanks
for your patience as we try to answer as many as possible.
[ Linda/NASAQuest - 42
- 08:47:57 ]
RE: When considering width alone, which of the following
volcanix forms on Mars would have the greatest width? a. shield b.cinder
c.strato/composite d.patera
If you want to try to stump your fellow students, put this one in the
forum at: http://archimedes.arc.nasa.gov/questchat/chatroom8/mod/chat.cgi
[ Jon_Rask/NASA_Ames
- 45 - 08:26:51 ]
Hello Everyone.
[ GeoffreyBriggsatNASAARC
- 46 - 08:26:55 ]
RE: [Linda/NASAQuest]
We will be starting the chat in about 1/2 hour. Please begin to enter
your questions early so that we may have a good chance of posting them
during the chat. Thanks!
I am on line now
[ Linda/NASAQuest - 47
- 08:28:27 ]
RE: [Jon_Rask/NASA_Ames]
Hello Everyone.
Good Morning Jon, Thank you for answering so many of the questions that
were submitted last chat - I am working on getting those online for our
students. We are seeing a slow trickling of new questions today. Hopefully
they'll speed up soon.
[ Linda/NASAQuest - 48
- 08:29:02 ]
RE: [GeoffreyBriggsatNASAARC]
I am on line now
Good morning Geoff, I'll start putting questions up now.
[ Jon_Rask/NASA_Ames
- 52 - 08:32:29 ]
RE: Shane, VISSA, CA Would Mars' surface have enough
nutrients to support plant life?
There should be enough to support plant life, however, you will need to
consider the damaging effects of radiation, extremely cold temps, and
very dry conditions.
[ Jon_Rask/NASA_Ames
- 55 - 08:34:23 ]
RE: Gregory - VISSA, CA Can plants survive on Mars?
If your plant was shielded somehow from radiation, and could somehow resist
dessication (drying out), and took advantage of some sort of extensive
microbial ecosystem to support it (assuming your plant was more than microscopic
in size)
[ Jon_Rask/NASA_Ames
- 58 - 08:37:35 ]
RE: waht do you do if you are a life support sciencetist.
I help to develop experiments that test hardware we will use to grow organisms
on the space station. I also help to develop the experiments that will
go into an incubator and a cell culture unit. The project I work with
is the Space Station Biological Research Project.
We want to make sure the hardware works before we launch,
so we have to test, test, test! Check, and re-check.
[ Linda/NASAQuest - 59
- 08:37:54 ]
PLEASE identify yourself - I see folks coming online, but so far only
Mrs. Laurino's class has told us they're here!
[ Jon_Rask/NASA_Ames
- 61 - 08:38:55 ]
RE: Jayme/Mrs. Anderson's 7th and 8th: Does Mars have
seasons?
Yes it does. Mars has a tilt of about 25 degrees which is quite similar
to the tilt of Earth. But, since Mars is further out in the solar system,
it travels more slowly around the Sun, which makes its seasons of "winter
spring summer and fall" much longer.
[ Linda/NASAQuest - 64
- 08:42:15 ]
Please don't repeat your questions - I see them in the moderation room
and put them in the chat room as we have time. Thanks
[ GeoffreyBriggsatNASAARC
- 65 - 08:42:20 ]
RE: Melissa/ Venture Academy, CA Can you tell us what
affects the Martian environment might have on humans if we were to live
there for several generations?
I'm not at all an expert in this area, Melissa, but the evolution of living
things takes place when random mutations occur that cause the organism
to become better adjusted to a new environment and thus to have a reproductive
advantage. So, even though the lower gravity of the martian environment
might well cause an astronaut's legs to grow weaker it would not affect
reproductive matters -- the DNA passed on from one generation to the next
would not change. However, if a terrestrial bacterium were released into
the martian environment and if it were not killed, then mutations would
lead to reproductibve advantages and so you would expect the baterium
to change to adjust to the higher radiation and the lack of ready access
to liquid water at the surface.
[ Jon_Rask/NASA_Ames - 69 - 08:45:57
]
Additionally, the human body would probably also lose bone mass, so the
bones would become brittle. If the effects of Mars are similar to microgravity,
then our immune system may also be supressed while living on Mars. And,
our blood chemistry (the hematocrit) would change. In general, astronauts
show symptoms in spaceflight that are similar to rapid aging.
[ GeoffreyBriggsatNASAARC
- 67 - 08:45:25 ]
RE: Is there any radiation or cosmic rays on Mars?
Elizabeth/CA
Elizabetth, Yes, the surface of Mars has much more ultra violet radiation
from the Sun because of the lack of an ozone layer like the one we have
on Earth. Cosmic radiation (from outside the Solar System and from the
Sun) finds its way to the surface of Mars much more easily than on earth
because the martian atmosphere is very thin.
[ Linda/NASAQuest - 71
- 08:51:43 ]
RE: has there been any new evidence that supports
the idea of an existing atmosphere on Mars? We put our name and location
in the location box but ended up being "unknown" so MsMookinisclass is
here
Great to see you! Yes, the Name box is broken, so your identifier needs
to be in the message box. Thanks
[ Jon_Rask/NASA_Ames
- 72 - 08:51:49 ]
RE: Could a Martian live underground? What could he
eat to survive? Would it be able to get it's energy from breaking down
Martian soil? What else could it eat?
That is certainly a possibility, and is probably the most likely place
biology would be located if at all. Since the surface is likely sterilized
by intensive raditation (and is incredibly dry and cold), biology in a
microbial form - if it were ever on Mars - may have retreated to the subsurface.
Radioactive materials that give off energy can split water molecules and
help to produce intermediary compounds, creating a chemical disequilibrium
(energy source) that could be used by microbes. We see such an example
in a gold mine in South Africa that is 3.5 km into the Earth! In fact
the researchers that are studying this place have shown that the communities
of microbes that grow there are cut off from the surface and are totally
unique in nature, when compared to surface microbes. Very fascinating
- this has astrobiological implications with respect to other planets
indeed, if biology somehow got there in the past, or formed there.
I hope this makes sense - radioactive materials in the crust
of the Earth are helping to produce compounds in the rocks that the microbes
'eat.' In this gold mine, they find these unique microbes in cracks of
rocks - they don't find them where there aren't cracks. So it seems there
needs to be some sort of interface.
[ GeoffreyBriggsatNASAARC
- 73 - 08:52:30 ]
RE: Mrs Laurino's class, MA If there is liquid water
underneath the surface of Mars would it be warm or cold?
We believe that temperatures increase at a rate of about 25 degrees C
per mile because, like Earth, Mars has an interior heated by radioactive
decay. Subsurface water on Mars will be frozen as ice in the top few miles
except in locations where there MAY be lingering volcanic heating. It
may be that all the subsurface water on Mars is locked in the frozen "cryosphere"
but there could be enough to fully saturate the fozen layer. If you descended
about 2 miles near the equator temperatures would be warm enough to allow
brines to exist (that is, water with a lot of salts in it). If you descended
further temperatures would eventually be reached (zero Centigrade/273
Kelvin) where water could be liquid without such salts. The temperature
would continue to increase at a rate of about 25 degrees Centigradeper
mile.
[ GeoffreyBriggsatNASAARC
- 78 - 08:58:35 ]
RE: [Linda/NASAQuest]
Great to see you! Yes, the Name box is broken, so your identifier needs
to be in the message box. Thanks
There is no question about Mars having an atmosphere -- we have measured
it many times. The pressure is very low -- only about one percent of that
on Earth. It is mainly composed of carbon dioxide with only small amounts
of argon, nitrogen and oxygen. There is just a trace of water vapor in
the atmosphere. During the winter months, the atmosphere condenses on
the dark polar cap at the same time that it sublimes from the illuminated
polar cap. There are thin water ice clouds in the atmosphere and, quite
often, big dust storms. The atmospheric circulation is like a simpler
version of Earth's -- simpler because there are no oceans on Mars to influence
the circulation.
[ Jon_Rask/NASA_Ames
- 80 - 08:59:40 ]
RE: Since we cannot merely "move" a human to Mars,
we cannot assume the existence of DNA as the life code. Therefore, in
creating our organism, do we need to address DNA as DNA or can we rename
the "life code" as something else. MsMookinisClass
Now you're really thinking! Excellent question. One of the big questions
astrobiologists have is, "if there was life on Mars, did it have an independent
and unique genesis/origin as the life on Earth?" Its a good bet that life
in the universe, if it exists elsewhere, is carbon based - but we have
to allow alternative possibilities. However, when you look to space, we
see the chemistry needed for life out there, and in roughly the same abundances
we see in this solar system.
We see that a unit of RNA (a single stranded template of
a DNA molecule), a ribosomal unit, seems to be ubiquitous, or present
in all life on Earth. We'd probably look to see if the 16sRNA unit were
in a 'Mars microbe' - and if it weren't there, then we might conclude
a unique origin. DNA seems to be a good working software for life.
[ GeoffreyBriggsatNASAARC
- 83 - 09:03:37 ]
RE: Mrs Laurino's 8th grade class - Massachusetts
We read that there is evidence that there were large bodies of water on
the surface of Mars. What do you think happened to the water? Was Mars
warmer before?
This is a big, unanswered question. Some of the water is locked in the
polar caps (which are a few miles thick). Some may be in glaciers buried
by dust. Much may have found its way into the subsurface where it is frozen
as gound ice. Some may be found beneath the permafrost in liquid form.
We also know that water can be physically adsorbed onto the dust and rubble
that make up the martian 'regolith" (top most surface materials). Some
has also been lost to space. Figuring all this out quantitatively is a
big challenge for the Mars exploration program.
[ Linda/NASAQuest - 87
- 09:06:51 ]
RE: Mrs Laurino's 8th grade class - Massachusetts
We read that there is evidence that there were large bodies of water on
the surface of Mars. What do you think happened to the water? Was Mars
warmer before?
Hi, Please check message 83 - Dr. Briggs answered your question.
[ Jon_Rask/NASA_Ames
- 88 - 09:07:57 ]
RE: Where would be the best place to look for microorganisms
in Mars? Are ice sheets a good place to look?
If there were microbes on Mars, the would want to live in places where
they could have access to liquid water (if we're assuming characteristsics
like Earth life) and biogenic nutrients. In areas rich in ice and snow
that may experience melting from time to time, or in the subsurface, deep
enough where the temps are warm enough and pressures are high enough for
water to be in liquid form.
Regions of permafrost may also be a good place to look -
since there is strong evidence that Mars had flowing water on its surface
for geologically significant time, microbiology may have found a niche.
After Mars changed, becoming very cold and dry and presumably losing much
of its atmosphere, the microbes - if they were there - could have been
frozen into the permafrost.
[ GeoffreyBriggsatNASAARC
- 90 - 09:09:10 ]
RE: I noticed that NASA simulations are dealing with
polar caps and permafrost (in Dr. Brigg's journal). May my Martian have
equipment to survive (I know he can't live in a bubble) such as clothing
that can be changed and maybe some machinery so it can live in changing
conditions?
You are obviously thinking of a very advanced form of martian life --
perhaps an astronaut who has decided not to return to Earth. In that case,
the martian would certainly have clothes and equipment to allow him or
her to survive in the rigorous conditions that mars presents.
[ Jon_Rask/NASA_Ames
- 96 - 09:13:00 ]
RE: Could a Martian live underground? What could he
eat to survive? Would it be able to get it's energy from breaking down
Martian soil? What else could it eat?
I think this was answered earlier.
[ GeoffreyBriggsatNASAARC
- 100 - 09:14:16 ]
RE: How hard is Mars' crust? What is under Mars'surface
that might harm my Martian?
The martian surface appears to be mainly made of rocks derived from magma
-- basalts that are very hard. However, the surface of Mars has been beaten
up by impacts (asteroids and meteorites) that has created a deep rubble
surface. In places there appear to be layers of sedimentary rocks, probably
less hard than the basalts. And there are lots of sand dunes. So, the
upper surface is dusty, sandy and rubbley; deeper it is probably pretty
hard. I hope this helps.
[ GeoffreyBriggsatNASAARC
- 101 - 09:15:54 ]
RE: What is the gravity like on mars?
Because Mars is much smaller than earth but made of similar materials
it has a les strong gravity field. It is about 38% as strong as that of
Earth.
[ Jon_Rask/NASA_Ames - 108 - 09:21:36
]
One thing is for sure - gravity shapes life. Biology reacts to the gravity
field of Earth according to genes that appear to be affected by gravity
- and there are lots of them! So, if you were to compare the same biological
specimen on Earth to it living/growning on Mars, it would most definitely
be affected and be changed. Gravity affects the shape of cells, how chemicals
are transported between them, and even how organisms grow. One experiment
with Moss cultures in space showed that microgravity induced a 'spiral
growth pattern.' Moss never exhibits that growth pattern on Earth. At
this time that mystery remains unexplained!
Note: at least for the kind of moss grown in this culture. [I'm not a
moss expert :) ]
[ unknown - 105 - 09:17:35 ]
Mrs Laurino's class, MA You said Mars became cold, dry, and lost much
of it's atmosphere. Do you have any idea why mars changed so much all
of the sudden?
[ Linda/NASAQuest - 112
- 09:23:18 ]
RE: thanks for the chat opportunity. Ms. Mookini's
Class
Thanks for joining us. We'll look forward to your final designs!
[ GeoffreyBriggsatNASAARC
- 113 - 09:24:23 ]
RE: Where would be the best place to look for microorganisms
in Mars? Are ice sheets a good place to look?
On Earth, in Siberia and in the Antarctic, micro organisms have been found
to survive for a very long time in ground ice -- perhaps as long as millions
of years. On Mars the inclination of the spin axis (presently about 25
degrees similar to Earth's) oscillates over a wide range (up to about
50 degrees) over time scales of about a million years. This oscillation
evidently can change the climate quite dramatically so searching the polar
caps is probably a good idea for future Mars missions. Of course, your
task is to design a martian rather than to search for one.
[ Linda/NASAQuest - 115
- 09:26:10 ]
RE: Mrs. Laurino's class, MA Thank you so much for
taking the time to help us. We learned a lot.
Thank you for your thoughtful questions. We look forward to seeing your
final designs.
[ unknown - 116 - 09:26:27 ]
thank you!!
[ Linda/NASAQuest - 117
- 09:27:40 ]
We will be wrapping up the chat in about 2 minutes. Thanks for joining
us, and thanks to our experts for you thorough answers!
[ Jon_Rask/NASA_Ames
- 118 - 09:28:32 ]
RE: If the Martian is a bacterial or viral, will the
climate affect the way my Martian survives? (Will it need warmth if it
bacterial or viral?)
Certainly. About viruses: they need a cell to do their work, so if you
have martian viruses, the will need a cell to replicate. But, perhaps
a symbiosis between the two could be imagined. Also, since the inclination
of Mars changes wildly (there isn't a big moon to stablize the planet's
spin), the planet tips up to 50 degrees! This means that there are periods
of time when Mars experiences a great deal more warming in the hemisphere
pointed to the sun that presently. As a result, those time periods may
be "when Mars blooms with biology". So I suppose its possible that there
are time periods that come only every million years when conditions may
be favorable for biology.
[ Jon_Rask/NASA_Ames
- 119 - 09:30:01 ]
RE: Can we design some sort of bacteria to grow on
Mars?
Absolutely. This is likely the most plausible idea. Go for it!
Growing IN the planet may also be easier to justify and support.
[ GeoffreyBriggsatNASAARC
- 122 - 09:31:48 ]
RE: What is the time like on Mars
The martian day is similar in length to the Earth's -- it is about 40
minutes longer (24 hours 37 min 22 sec). We call a martian day a "sol".
The year is quite a bit longer -- 687 days. Because the martian spin axis
is tilted at about 24 degrees (similar to Earth's), Mars experiences seasons
as we do. Of course, each season is much longer because the year is longer.
On Earth the seasons are of equal length because Earth is in a near circular
orbit about the Sun. By contrast, Mars has a somewhat eccentric orbit
and as a result the seasons are not all the same length.
[ Linda/NASAQuest - 121
- 09:31:32 ]
We are not accepting any more questions at this time. Though our experts
may still be working on answering some of your questions, we will not
be posting new ones. Thanks for joining us.
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