Date: December 10, 1997
Featuring: Jim Murphy
Meteorologist, Mars Pathfinder
Ames Research Center, Pasadena, California
[ MrsDabbs1stgrade/WestView-murphychatter 09:55:05 ]
Hello!
[ Harris8thgrade/KPNorth-murphychatter
09:57:34 ]
Hello
[ Marske/SiouxCenterMiddleSchool-murphychatter
09:57:59 ]
We 6th graders are here in Sioux Center, IA looking out at
the snow that has slowly accumulated over a few days to about 3 in. total.
We have read Jim Murphy's bio and are very pleased to have the opportunity
to visit with him. Students will be coming and going as schedules come
and go. That's OK. More students can participate that way.
[ Harris8thgrade/KPNorth-murphychatter 09:58:48 ]
Mrs. Dabbs
first grade what is the weather like there? (CA?)
[ Gagnersclass/MorrisMN-murphychatter
09:59:03 ]
Hello everyone
[ Bill/ForestParkES-murphychatter 10:00:03 ]
Hello everyone!
[ Donna/KaiserElementary-murphychatter10:00:35 ]
Hi, Mrs. Ewing
here with two of my 4-6th grade students.
More will join us in a few minutes. It is cold and windy
for southern California! Hi everyone.
[ MrsDabbs1stgrade/WestView-murphychatter 10:01:39 ]
It is
cold, but no snow..yet. We are in Washington. Where are you?
[ Harris8thgrade/KPNorth-murphychatter 10:03:22 ]
Mrs. Dabbs
first grade what is the weather like there? (CA?)
[ Gagnersclass/MorrisMN-murphychatter 10:03:41 ]
It's cold here
in Morris,MN.
[ MrsOsClass/Barre-murphychatter 10:03:54 ]
Hi,
We're a Fourth Grade Class from Barre, Vermont.
[ MrsDabbs1stgrade/WestView-murphychatter 10:04:18 ]
Mr Murphy:
Is the wind so stong that is makes sandstorms?
[ Harris8thgrade/KPNorth-murphychatter 10:05:02 ]
Mrs. Dabb, it
is cool here in Mass. we are expecting snow.
Hi Mr. Murphy!
[ Sandy/NASAChatHost10:05:07 ]
Hello
Everyone! Jim Murphy is here and ready to go! Hope you have your questions
ready :-)
[ JimMurphyAmes10:05:20 ]
Hello All,
I am happy to be here with you today to chat about Mars, and Earth, and
their similarities / differences...
[ Bill/ForestParkES-murphychatter 10:05:34 ]
no snow here in
Nanaimo, Canada we're on the west coast and our flowers are still
blooming! but this is unusual.
[ MrsOsClass/Barre-murphychatter10:06:03 ]
It's cold here in
Vermont (about 24 degress F).
[ Sandy/NASAChatHost10:07:08
]
Welcome to Bill in Nanaimo, Canada! Sounds like El Nino is in effect
up there too!
[ JimMurphyAmes 10:07:57 ]
RE: [Gagnersclass/MorrisMN-murphychatter] Is there
precipitation on Mars?
Yes, there probably is precipitation on
Mars, but is all in the frozen form (i.e. snow). The water in the
martian atmosphere is either in the gas (water vapor) state or the frozen
state (snow, ice on the ground). There is also likely
carbon dioxide (CO2) snow, since CO2 is the main component of the
atmosphere, and it freezes out in the winter polar regions. If it freezes
out in the atmosphere, the frozen CO2 snow particles will flutter to the
ground, just like the snow we are familiar with...
[ JimMurphyAmes 10:10:25 ]
RE: [MrsOsClass/Barre-murphychatter] Here's one of
our questions for Jim.
What's the difference in temperature between Mars and Earth?
In
general, the temperatures on Mars are much colder then here on Earth. A
warm day on Mars might have air temperatures near the ground get up to 40
degrees fahrenheit
(but not very often or at too many places), while the coldest spots on
Mars see temperatures as cold as -200 degrees Fahrenheit, which is colder
than even the coldest temperature measured in Antarctica.
[ Gagnersclass/MorrisMN-murphychatter 10:11:51 ]
We have to go
to lunch now, we'll be back in fifteen minutes.
[ Sandy/NASAChatHost 10:12:49
]
RE:
[LabbaneWood/SoutheastElementary-murphychatter] Hello from
Southeast Elementary in Jenks, OK! Sorry we're late...technical
difficulties! We are fourth graders in Mrs. Labbane's and Mrs. Wood's
class. We're excited about chatting with you!
Welcome
LabbaneWood Southeast Elem.!!! I'm very happy to see that you worked
through your technical difficulties!!!
[ MrsOsClass/Barre-murphychatter 10:12:54 ]
Jim,
How fast has the wind ever blown on Mars?
[ JimMurphyAmes 10:26:09 ]
Mrs.
Os: The wind on Mars has probably never blown faster than about 400
miles per hour. We can determine this because the wind can't blow fatser
than the speed of sound, and the speed of sound on mars is 400-450 miles
per hour; at the surface of mars, I would guess that the fastest wind is
probably 150-200 miles per hour...but that ir really just a guess.
[ JimMurphyAmes10:12:57 ]
RE: [Marske/SiouxCenterMiddleSchool-murphychatter] Do
you think we could ever live on Mars considering the weather
there?
Yes, I think we could live on Mars even considering the
temperatures there, but you would not catch me running around outside in
shorts !! People who travel there will be required to live within
contained environments (i.e. spacesgips), since there is no air to
breathe. Just as people now spend the winter at the Earths South Pole
(where it gets pretty darn cold), I think that we can deal with the cold
Martian temperatures, especially if we were near the equator, where it
probably does not get much colder than minus -120 degrees Fahrenheit or
so...
[ LabbaneWood/SoutheastElementary-murphychatter 10:13:39 ]
Why
isn't there an ozone layer on Mars?
[ JimMurphyAmes 10:27:49
]
Labbane/Wood: Good question. There is essentially no ozone layer on
Mars, since there
is hardly an oxygen (2) on Mars, and since to produce ozone (3) the
oxygen must be 'broken' in half (procuding two O molecules) with each
molecule being added to another oxygen molecule, that lack of oxygen leads
to a lack of ozone.
[ JimMurphyAmes 10:15:00 ]
RE: [Harris8thgrade/KPNorth-murphychatter] Mr. Murphy
we have been studying weather and have been impressed with the differences
in temp. - what are the temperature ranges now on mars?
The maximum air temperatures near the surface are probably +40
Fahrenheit or so, while the coldest temperatures near the surface are
probably -230 Fahrenheit or so.
[ MrsDabbs1stgrade/WestView-murphychatter 10:15:43 ]
Mr.
Murphy: Are you worried about the weather harming the Pathfinder?
[ JimMurphyAmes 10:30:01 ]
Mrs.
Dabbs: Well, I wish I were worried about the weather harming
Pathfinder. We believe that Pathfinder is no longer working, probably
because the cold temperatures caues some part of the inside of the
spacecraft to break, since things tend
to become more likely to break or crack when the get very cold (I always
tend to think of plastic trash cans cracking in cold weather...)
[ LabbaneWood/SoutheastElementary-murphychatter10:15:56 ]
Can
the technologies used on Pathfinder be used here on Earth?
[ JimMurphyAmes10:32:01
]
Labbane / Wood: Yes, the technologies used on Pathfinder can be
used here on Earth. The stereo camera capability is used to produce 3-D
movies (horror movies from teh 50's are prime examples), the rover has
shown that a remotely controlled vehicle can be driven around to do
science, and in fact such a rover was used in the desert of Chile earlier
this year.
[ JimMurphyAmes 10:16:36 ]
RE: [Donna/KaiserElementary-murphychatter] We know
that it is much colder on Mars. This is because the sun is farther away.
What other reasons are there, Mr. Murphy?
Good question! Mars
is colder because it is farther from the sun, and additionally it is
colder because there is less atmosphere on Mars, which produces a less
intense 'green house' effect (that is, the blanketing effect provided by
the atmosphere).
[ MrsDabbs1stgrade/WestView-murphychatter 10:18:03 ]
Mr.
Murphy: Do parts of Mars have seasons like Earth?
[ JimMurphyAmes 10:33:25
]
Mrs. Dabbs: Yes, you are correct, all parts of Mars have season
just like here on Earth. So, during the summer it is warmer than in the
winter. But, since Mars does not have trees, there are no pretty colors
in the autumn, nor blooming flowers in the spring :)
RE: [Gagnersclass/MorrisMN murphychatter]
How does the pressure on Mars compare to Earth?
The surface pressure of the atmosphere on mars is about 7
millibars (a unit of measure of pressure), compared with the surface
pressure here on the surface of the Earth of 1013 millibars (29.93 inches
of mercury, in a secoond unit of measure)
[ JohnWaylandElementary-murphychatter 10:18:56 ]
How does the
extreme conditions on Mars affect the instruments? Can you use the same
instruments that we use on Earth to measure temperature, wind speeds, and
pressure on Mars? Did you build special instruments so they would work on
Mars?
[ JimMurphyAmes 10:38:03
]
John Wayland: We can use the same type of pressure measuring
instruments on both Earth and Mars; using a liquid in glass thermometer
would not be too great an idean on Mars, since the limited number and slow
motion of the molecules would mean that it would take a while for the
thermometer to respond; we use electrical temperature measuring devcices
on Mars. For wind, something which moves due to the wind is less
desirable than some electrical or temperature measuring device.
[ Marske/SiouxCenterMiddleSchool-murphychatter 10:19:41 ]
Do
they have El Nino like phenomenon that might cause storm conditions like
here on Earth?
[ JimMurphyAmes 10:39:49
]
Marske: Well, since Mars does not have oceans, and El Nino is
really a change in ocean water temperatures and their effects upon the
weather, mars won't have El Nino's like we doe here on Earth,....but, if
the dust on the surface were to move around, and clear from some areas and
appear in others, the effect on the surface temperatures might gewnerate
weather variations which maybe we could call 'El Dustos'!
[ JimMurphyAmes10:20:11 ]
RE: [Marske/SiouxCenterMiddleSchool-murphychatter] We
were wondering what kind of weather do you like to study?
In the
case of Mars, I like to study the weather processes which lead to the
development of global dust storm. During these storms, dust is lifted
into the atmosphere and covers much of the planet...we don't have any
similar type of weather event here on Earth. I'm also studying what
might be dust devils on mars. Here on Earth, I am interested in
hurricanes and tornadoes / dust devils
[ Harris8thgrade/KPNorth-murphychatter10:20:16 ]
How thick can
the snow get? Does it pile up?
[ JimMurphyAmes 10:40:45
]
Harris: The 'snow' might pile up to several meters depth (1 meter
~ 3 feet) at the polar latitudes in the polar cap.
[ Bill/ForestParkES-murphychatter 10:20:19 ]
Why in the winter
do the polar ice caps grow?
[ LabbaneWood/SoutheastElementary-murphychatter 10:21:13 ]
Is
there a rating scale for the dust devils on Mars similar to the F scale
for tornadoes?
[ JimMurphyAmes 10:42:12
]
Labanne / Wood: There is no official rating scale for dust storms
on Mars, but we tend to refer to them (from small to big) as local,
regional, hemispheric, planetary, and Great with the distinction between
planetary and great and matter of opinion.
[ Harris8thgrade/KPNorth-murphychatter 10:22:00 ]
Samrout would
like to ask how the dust stroms in Lebanon compare to Martian storms?
[ JimMurphyAmes 10:44:23
]
Harris/ Samrut: The dust storms in Lebanon compare with Mars
storms in that both result from strong winds near the surface which bounce
big sand particles around which, when the hit the ground. knoock small
dust particles into the air. These dust particles are small enough for
the wind to carry them up and away. However, the Lebanese storms tend to
be smaller than the regional and larger storms on Mars.
[ JimMurphyAmes 10:22:38 ]
RE: [Bill/ForestParkES-murphychatter] why are there
such big temperature changes in such a short time ?
I'm not
quite sure about what large time changes of temperature you are talking
about, but if they are day night differences, the change is due to the
'green house' type argument a few answers back. If there is less
atmosphere above you, the ground can emit thermal radiation to space
without much coming back from the atmosphere. This means the ground cools
very efficiently, and so does the air in contact with it.
[ JohnWaylandElementary-murphychatter 10:23:13 ]
Another
question we have? Can the weather information that we gather from Mars
tell us anything about its past? Also, our earth has had periods of
warming and cooling (ice ages) did Mars have any extreme weather changes
from warming to cooling.
[ JimMurphyAmes 10:45:44
]
John Wayland: The weather today can't really tell us too much
about weather in the past, but the various features on the planet's
surface, such as apparent water channels, and layering in the polar ices,
do suggest that Mars was warmer and wetter long, long (billions of years)
ago.
[ JimMurphyAmes 10:24:31 ]
RE: [Harris8thgrade/KPNorth-murphychatter] How long
is it light for at the martian poles?
Just like here on Earth,
the sun shine at the martian poles for one-half of a martian year, from
the neginning of spring through the end of summer. Mars is tilted 25
degrees, compared with Earth's 23.5 degree tilt (or is it 22.5?), and it
is this tilt of the ratation axis which produces our, and Mars' seasons.
[ MrsOsClass/Barre-murphychatter 10:25:20 ]
Sorry, we need to
leave now. Thanks for all the great information!
[ Marske/SiouxCenterMiddleSchool-murphychatter 10:25:58 ]
Did
you have a role model when you decided to go into meteorolgy?
[ JimMurphyAmes 10:46:52
]
Marske: I don't recall a specific role model who interested me
in meteorology. But I do remember talking with several of the TV
meteorologists in New Orleans when I was in junior high and high school,
and in general they were encouraging of my interest in weather.
[ LabbaneWood/SoutheastElementary-murphychatter 10:25:58 ]
Do
you plan on being a team member for the next rover in 2001? If so, what
changes would you make?
[ JimMurphyAmes10:48:14
]
Labanne / Wood: I would love to be a member of one of the
upcoming missions to mars. I I have the chance, the one thing I would
change is to do more work testiung all our weather instruments before they
go to ensure that they work properly.
[ Gagnersclass/MorrisMN-murphychatter 10:26:57 ]
Hello, we're
back.
[ Bill/ForestParkES-murphychatter 10:28:46 ]
are there seasonal
variations in temperature on mars?
[ LabbaneWood/SoutheastElementary-murphychatter 10:28:49 ]
In
what season do most dust devils occur?
[ JimMurphyAmes 10:49:44
]
Labanne / Wood: Good question... Surprisingly dust devils
have been observed during all seasons on Mars, at the three northern
hemisphere sites at which we have had landers. Here on earth, they are
primarily a summer time feature of the wetaher in hot, deserty regions.
[ Marske/SiouxCenterMiddleSchool-murphychatter 10:29:13 ]
What
is the most extreme weather on both Earth and Mars?
[ JimMurphyAmes10:51:19
]
Marske: On Earth, the hottest temperature ever recorded is 134
degrees Fahrenheit, in Libya, which the coldest is something like minus
134 Fahrenheit, at the South Pole. On Mars, the warmest we have ever
measured is about 25 degrees fahrenheit, while the coldest is -190
Fahrenheit or so.
[ Gagnersclass/MorrisMN-murphychatter 10:29:34 ]
What are the
average high and low temps on Mars ?
[ JimMurphyAmes 10:57:08
]
Gagners: The average high temperatures observed by Pathfinder,
during northern summer, were +10 Fahrenheit, while the average minimum
was -110 F or so.
[ MrsDabbs1stgrade/WestView-murphychatter 10:29:54 ]
Mr.
Murphy: Are there clouds on Mars?
[ JohnWaylandElementary-murphychatter 10:32:17 ]
We
live in a Valley and a lot of our weather is affected by the mountains and
other geographic features. How do the geographic features of Mars play a
role....Like Olympus Mons?
[ JimMurphyAmes 10:54:40
]
John Wayland: The Shenandoah Valley is beautiful..I envy you
living there. The mountains and Valleys on Mars do effect the weather.
The big volcanoes are often the site of cloud formation as air rides up
their sides, cools as it does, and condenses, forming clouds. STorms
ofetn generate down stream of mountain ranges here in eart, and the same
apparently holds tru on mars.
[ Marske/SiouxCenterMiddleSchool-murphychatter 10:32:55
]
We were wondering about the life of a busy scientist. Do you feel
like you have enough time with your family?
[ JimMurphyAmes 10:52:51
]
Marske: There are often times when I feel like I don't have
enough time with my family, but in general I think it works out OK. My
really beusy times at work tend to come in spurts, not all the time, so I
try to spend as much time at home when things are'nt too hectic. I was
away for an entire month for mars Pathfinder this past July, but then we
took a family vacation in August. It was fun.
[ Sandy/NASAChatHost 10:33:47
]
EVERYONE: Jim is typing as quickly as he can, but we are about 20
questions behind. He wants to answer ALL of your questions. Hold up
sending questions for 5 minutes.... Thanks :-)
[ Marske/SiouxCenterMiddleSchool-murphychatter 10:35:06
]
What inspired you to work on the Mars Pathfinder project?
[ JohnWaylandElementary-murphychatter 10:35:26 ]
Been
there...done that...Marilyn
[ LabbaneWood/SoutheastElementary-murphychatter
10:37:36]
Is the atmosphere of Mars ever dust-free?
[ JimMurphyAmes 10:35:29
]
Labbane / Wood: The dust probably does not ever completely clear
from the martian atmosphere. ALl three spacecraft we have placed on the
surface have seen dust in the atmosphere all the time. There might be
locations where most of the dust clears at some time, and it might become
less deeply mixed into th eatmosphere at some seasons, but I think there
is always some dust in the atmosphere.
[ LabbaneWood/SoutheastElementary-murphychatter 10:37:36
]
Thanks for your time, Mr. Murphy. We really enjoyed chatting with
you and the other schools, and we learned a lot. Our time is up...best
wishes from Southeast Elementary in Jenks, OK. :)
[ MrsDabbs1stgrade/WestView-murphychatter10:38:08
]
Thankyou Mr. Murphy for chatting with us! Thanks for everything!
[ Gagnersclass/MorrisMN-murphychatter 10:39:27 ]
Goodbye
LabbaneWood/SoutheastElementary.
[ JohnWaylandElementary-murphychatter 10:44:33 ]
On Earth we
gather much of our weather information from satellites. NASA just sent up
a new satellite (TRIMM) to measure rainfall. We know about MGS orbiting
Mars. Can we use a system of weather satellites for Mars too?
[ JimMurphyAmes 10:56:02
]
John Wayland: Yes, we can use a system of weather satellites
for mars. The satellites should carry cameras so that we can see clouds
and dust storms, and the satellites should also carry instruments to 'see'
infrared wavelengths, from which we can determine temperatures of the air
and ground.
[ Marske/SiouxCenterMiddleSchool-murphychatter 10:45:22 ]
We
were wondering what has been the most interesting information you've
gotten from the Mars Pathfinder?
[ JimMurphyAmes 10:59:08
]
Marske: The most interesting weather info I think we have
gotten from mars Pathfinder is how rapidly the air temperatures near the
ground change over the time interval of a few minutes during the day.
Tempearture changes as large as 30 degrees Fahrenheit occur within a few
minutes, followed by a return to the original temperature. This indicates
that hot air is rsing and cold air is sinking quite drmatically.
[ Gagnersclass/MorrisMN-murphychatter 10:48:24 ]
Has the
weather changed since the Viking missions and if so, how?
[ JimMurphyAmes 11:01:05
]
Gagners: The weather does not appear to have changed too much
since the Viking missions. Pathfinder landed about 1000 miles from Viking
lander 1, and the temperatures, pressures, winds, and dust amount in the
atmosphere seen by Pathfinder look quite a bit like what we saw at Viking
Lander 1, 11 mars year earlier ( a Mars year is about 689 Earth days, or
669 mars days; a Mars day is 24 hours and 37 minutes long, so just
slightly laonger than our day here on Earth...)
[ Marske/SiouxCenterMiddleSchool-murphychatter 10:50:26
]
Do you think your job is fun? And why?
[ JimMurphyAmes 11:02:50
]
Marske: My job is great fun !!! It was real thrill being
involved in Pathfinder, and realizing that I was the first person seeing
the weather data from mars from that mission. It is a great joy trying
to learn new things, and answer questions which no one else has. Also, it
is nice being able to choose the topics I want to study, at least a good
part of the time.
[ Marske/SiouxCenterMiddleSchool-murphychatter10:54:41
]
What do you plan to do with the weather data from Mars?
[ JimMurphyAmes11:04:20
]
Marske: The weather data we have collected we are presently
studing to learn more about martian weather (dust devils, storm systems,
heat transfer from the warm ground to thge atmosphere, and other such
topics). Beginning next month, all the data will be made available to
anyone who wnats it, so they (and you!) can study it as well...
[ Marske/SiouxCenterMiddleSchool-murphychatter 10:58:39
]
Not to be personal, but we were wondering what kind of a salary does
a scientist like you make a year?
[ JimMurphyAmes11:06:30
]
Marske: I am happy with what I make. I think the range of
salaries probably starts at $25-30 thousand per year, and goes up to
$70-100 thousand for tenured professors. I am definitely towards the low
end of the scale, but for the work I am able to perform, and the freedom I
feel, I don't have much complaint about my salary.
[ Marske/SiouxCenterMiddleSchool-murphychatter11:00:15
]
We would like to thank Mr. Murphy for spending quality time with us
today. We learned a lot and appreciated chatting with you. Bye from
Sioux Center.
[ Bill/ForestParkES-murphychatter 11:01:17 ]
If Mars
has a very thin atmosphere why did the pathfinder get so hot when going
through the thin martian atmosphere?
[ JimMurphyAmes 11:08:53
]
Bill in Canada: Good question. Even though Mars has a 'thin'
(not meant to imply shallow), Pathfinder got so hot descending through the
atmosphere in part because it was travelling so fast (15,000 miles per
hour), and those molecules in the air 'drag' on the spacecraft and slow it
down, and in tyhe process that friction generates heat (like a rope burn
for those unfortunate enough to have experienced that).
[ Gagnersclass/MorrisMN-murphychatter 11:04:57 ]
Do you
know why the satellites of Mars are not round like the Earth's moon?
[ JimMurphyAmes 11:12:33
]
Gagners: Really good question! I think the current idea is
that our moon formed after a collision with Earth by large object
which threw some material into orbit around Earth, and this material
formed into a rotating mass which eventually forms a sphere. At mars, it
is believed that Phobos and Deimos might be captured asteroids. And,
since
asteroids are thought to be possible remnants of bigger pieces which
broke into small pieces when they collided out in space, they have jagged
edges since they are pices broken off from a larger body (a bit like
smooth glass breaking into jagged pieces...).
[ Sandy/NASAChatHost 11:12:36
]
EVERYONE: It's time for Jim to get back to work! Thanks to all of you
for doing your homework before the chat and asking such detailed and
thoughtful questions! You did a great job! And a special THANK YOU to JIM
for taking the time to spend with us today. Your answers were very
informative, and I for one, learned some new things.
HAPPY HOLIDAYS TO EVERYONE AND JOIN US AGAIN IN JANUARY FOR NEW CHATS :-)
[ JimMurphyAmes 11:13:31
]
Thanks for the terrific questions. This is a terrific way to spend
my time (and just one more reason whiy I love my job). Ya'll take care
out there, have fun studying about space, and have a happy holiday season.
Jim Murphy.
[ Sandy/NASAChatHost 11:24:04
]
RE: [Bill/ForestParkES-murphychatter] Ta
ta from forest park school Nanaimo British Columbia we've had a great time
chatting so long for now.
GOODBYE Bill! So glad you could join
us today ;-)