Live From Mars was active July 1996-December 1997.
Challenge Questions
Classroom Responses
>>>>>>>>>>Week #3 Challenge Question RESULTS <<<<<<<<<<
THE PARTICIPANTS THIS WEEK:
A BIG THANKS to the following classes and individuals who participated
in Challenge Question Week #3:
David Rajan (California)
Thabet Al Fishawi (Egypt)
Florian Breuer (South Africa)
Sean Masterson
Matt Krell (Mississippi)
David Press (California)
Michael McVey's HS Class (Arizona)
Jeff Hill (Utah)
Oirand Floresca
John Bayne (Australia)
Mr. Grott's Class (New York)
Brian Grigsby's Class (California)
The Students of Blessed Sacrament School (Washington, DC)
Philip Gressman (Missori)
Mike Reynolds' Class (Michigan)
Edward Beidas' HS Class (Illinois)
Norma Barnes' Seventh and Eighth Graders (Missouri)
Cathy Peterson Fifth Grade Class (California)
Janet Cook's Alternative HS Class (Colorado)
Charlotte Steven's 8th Grade Class (Georgia)
Tim McCollum's 8th Grade Class (Illinois)
Dr. Thomas Keens (California)
Mrs. Heine's 5th Grade Class (Florida)
John Herrold - 9th Grade Class
Mark Hines' Class (Hawaii)
Monticello Schools 5th Grader Jake Argo (Wisconsin)
Robert Moncello
THE BEST ANSWERS WERE GIVEN BY THESE PARTICIPANTS:
There were so many participants who explained the solution correctly that
we were really impressed with your problem solving skills. The BEST
explanations
were selected based on clarity and accuracy.
High School Level: Philip Gressman, HS Senior at Ava, Missouri
Middle School Level: Jerry Trammell, 7th Grader Cranbrook Kindswood MS,
Bloomfield, MI
Elementary Level: Mrs. Heine's 5th Graders, Palm Bay, Florida (second
answer)
CONGRATULATIONS TO ALL!!
THE REAL WINNERS = EVERYONE WHO GAVE THEIR BRAINS
A WORKOUT TRYING TO SOLVE THIS PUZZLER! Thanks to ALL of
YOU. We are glad to see adults and college level
students involved and participating just for fun!
*********************************************************
COLLATION OF ALL ANSWERS RECEIVED:
--------
Bob
To: jwee@mail.arc.nasa.gov
Subject: Challenge Question #3
The reason that Deimos appears to move from east to west in the Martian
sky is due to the fact that Deimos orbits Mars faster then Mars
rotates. On the other hand the reason Phobos seems to move from west to
east is because it's orbit is slower then the rotation of the planet,
this is what gives the illusion that the moon is moving backwards.
For example: imagine you were watching a race from the middle of the
race track, as you spun counterclockwise (from right to left)to keep an
eye on the lead car the other cars would seem to be moving off to your
right (from the left to the right). We all know however that the cars
do not really change direction the just appear to be because they are
not traveling as fast as the lead car.
Robert J. Moncello
---------
David Rajan
Reply-To: kiwiman@ix.netcom.com
To: jwee@mail.arc.nasa.gov
Subject: CHALLENGE QUESTION
Just a quick guess on the Mars moon question. Does it have anything to
do with parallax, or maybe does one of the moon's speed so that when it
rotates, you don't see it rotating in the proper direction so that
during every interval you see it, it is in the opposite direction of its
rotation, giving the appearance of its moving backwards?
I don't really know how to explain this, but is it similar to the way
stagecoach wheels turn backwards in movies (because of the camera's
shutter speed, because the movie camera displays 24 frames/sec. so that
every one 24th of a second, the spoke's position is counterclockwise to
the position it was in the frame before even though it's moving
clockwise? Whew! I'm not sure if it's even remotely right, but is it a
valid guess?
David Rajan, senior at
Bishop O'Dowd High School in Oakland, CA
----------
Thabet Peter Al Fishawi
To: jwee@mail.arc.nasa.gov
Subject: CHALLENGE QUESTION
Dear JAN
That is because Deimos have a realtivly long orbital period (
1.26 days )in comparrison with Phobos , so if we liken Deimos to our
moon , they both rotate from east to west , and that is not due to thier
motion but due to the rotation of the planet " Earth or Mars " , while
Phobos has a very short orbital period ( 0.32 days ) so it's movment
across the sky is its real motion in the space , which is from west to
east. like any other moon.
Thabet Al Fishawi
I'm in 2nd year secondary, I live in Cairo, Egypt.
----------------
From: "MNR. F BREUER"
Hi!
Here my brief answer to challenge question #3,
Both moons orbit Mars in the same direction, but, because of the different
distances from Mars, they orbit at different speeds. Mars itself is
rotating in the same direction, with an angular velocity that is in
between the angular velocities of the two moons' orbits. So that means
that while the one moon (I don't know which one, doesn't matter) is
orbiting in one direction the martian surface is rotating away faster
under it, so to the observer on the surface the moon appears to be moving
backwards. The other moon, however, is orbiting faster than the surface
(expressed informally) so it "overtakes" the surface and thus an observer
on the surface sees this moon moving forwards.
That was somewhat informal, by speeds I actually meant angular velocities.
Cheers,
Flo.
(Florian Breuer, 2nd year maths student at the University of Stellenbosch,
South Africa)
------------
Masterson, Sean"
Subject: RE: CHALLENGE QUESTION
Date: Mon, 4 Nov 1996 01:54:45 -0800
>CHALLENGE QUESTION #3: MOONS OF MARS
Well, I don't know the length of a Martian day or the orbital periods of
either moon but the apparent retrograde motion must be due to Phobos
moving more slowly than the speed at which Mars rotates and Deimos
moving more quickly.
When you give out the correct answer, could you explain whether there
would be a way for an observer on the surface of Mars to prove that the
two moons travelled in the same direction? Many thanks.
-----------
mitch krell
To: jwee@mail.arc.nasa.gov
Subject: Challenge Question#3
My answer is as follows:
While the two moons orbit Mars, Mars is also rotating. As the motion of
the two moons is retrograde(opposite)to that of Mars, Mars rotates
faster than the further moon, thus causing it to appear to move with
Mars's rotation
Matt Krell, Hattiesburg, MS
8th Grader (participating on his own)
-----------
Dave Press
To: jwee@mail.arc.nasa.gov (Return requested)
Subject: CHALLENGE QUESTION
CHALLENGE QUESTION #3: MOONS OF MARS
Here is a new puzzler for this week:
Mars has two moons: Deimos and Phobos. If you stood on the surface of
Mars and looked up into the night sky, you would see Deimos slowly
travel from east to west across the sky while Phobos would be slowly
traveling from west to east.
In other words, the two Martian moons travel in opposite directions
across the Martian sky. Yet both moons actually orbit Mars in the same
direction.
Explain this apparent paradox.
My guess is that the angular velocity of Phobos' orbit is less than the
angular velocity of the planet's rotation and that this would make the
moon appear to be traveling backwards with respect to the planetary
surface.
David Press (college junior who is participating just for fun!)
Los Angeles Pierce College
Woodland Hills, California
------------
Michael McVey
Subject: Challenge Question (Mars Moons)
Martian Moon Question
Chisa Valdez (Grade 9) and Karla Curiel (Grade 9) of Desert View High
School make the following submission:
If one of Mars' moons has an orbit that is slower than Mars' speed of
rotation and the other moon has a faster orbit - then one moon would
appear to move opposite the other.
Desert View High School
Teacher: Michael McVey, mmcvey@ccit.arizona.edu
------------
Alan & Cath'e Troyer"
Subject: CHALLENGE QUESTION
The reason it appears that the Martian moons Phobos and Deimos are
traveling in different directions is because the rotation of Mars is
greater than the revolution of Deimos, making the appearance that Deimos
is traveling in the opposite direction, while Phobos' revolution is
greater than the rotation of Mars.
Jeff Hill, age 17
Salt Lake City, Utah
--------------
Floresca, Oirand C." <09619755@mail2.dlsu.edu.ph>
Subject: CHALLENGE QUESTION
Mars rotate counterclockwise from it's axis. If you would look to the
two moons deimos and phobos on Mars you would see phobos travelling
from west to east and deimos from east to west. You see this because
Phobos is in a higher orbit than Deimos. Therefore it would only take
Deimos a short time to orbit Mars while Phobos would take a little
bit longer. Eventhough they revolve around Mars in the same direction
which is to the west Phobos would look like it is travelling from
east to west because it could not keep up with the rotation of Mars
and the revolution of Deimos.
---------------
John Bayne
Subject: CHALLENGE QUESTION
If you were to look at Phobos and Diemos from Mars, the reason you would
see them moving in opposite directions, even though they are travelling
the same way would be that Mars is rotating faster than one, and slower
than the other. Therefore, comparitively, Mars would be "Overtaking" one
moon and would be "overtaken" by the other.
John Bayne, 15-year old, in grade 10 at Saint Augustine's College,
Cairns, Queensland, Australia.
-----------------
Dave Grott
Subject: Challenge Question #3 - Mr.Grott's Class
We calculated that Phobos is only 3750 miles above Mars and will
eventually crash into the surface. Demios is 12500 miles above the
surface. It orbits Mars every 60 hours while Phobos orbits Mars 3 times
per Martian day. We labeled East and West on the Blackboard. Danielle
volunteered to be Mars the Planet and our observer on the surface.
Patrick was Demios, he did not move because it takes 60 hours to complete
one rotation. Tim was Phobos because Phobos orbits every 7 hours and 39
minutes. He ran, and ran, and ran around Danielle. As Tim moved Danielle
was able to see Tim with her left eye and then her right eye, the left
being west and the right east. Phobos appears to rise in the west because
it is so close to the surface and travels so fast.
Mr.Grott's Class
Alden Place Elementary School
Millbrook, New York
Dear Jan Wee;
We found the question to challenging but we enjoyed solving it. We had a
problem because your data was not accurate. Phobos travels faster than
you stated. Timing for the observation is critical. Demios moves like
the needle on a gas gauge, basically we ignored your data and used our
own.
Mr.Grott's Class
----------------
bgrigsby@shasta-co.k12.ca.us (Brian Grigsby)
Subject: CHALLENGE QUESTION
My Students Troy Goddard and Briar Clements had the following
answer to Challenge Question #3:
Even though the moons appear to travel opposite directions, the rotation
of Mars is such that it rotates faster than Phobos orbits around it.
Thereby causing the appearance of the moons to orbit in opposite
directions.
Brian Grigsby
Shasta High School
2500 Eureka Way
Redding, CA, 96001
bgrigsby@shasta-co.k12.ca.us
-----------------
science@sysnet.net
Organization: Blessed Sacrament
Answer to Challenge Question of October 28 1996:
The way it works is that Deimos and Phobos are different lengths
from Mars along with both orbiting at different speeds. Deimos travels
once around Mars in a day while Phobos travels twice around Mars in
one day. That means if you look up from Mars you will see Deimos going
one way and Phobos going the other way.
From: Jonathan, Robert, Lydia, and Joe
Blessed Sacrament School
-----------------
science@sysnet.net
Organization: Blessed Sacrament
Our Answer:
The reason why the moons Deimos and Phobos appear to travel in
opposite directions is that the two moons travel at different speeds.
The one planet that travels faster is probably closer to Mars. The
closer you get to a planet, the more the gravitational pull is, so
this explains the faster speed. The second moon orbits farther away
from Mars, so its orbit speed is slower. This slower speed makes it
look like it is travelling backwards compared to the other moon.
However, as stated in the question, both moons are travelling in the
same direction.
>From team 5 at Blessed Sacrament:
Devin Delany, Tara Quinn, Andrew Latimer and Teddy Rykowski
-----------------
science@sysnet.net
Organization: Blessed Sacrament
Subject: Challenge Question # 3
Our Answer:
Mars is rotating to the right at a certain speed. The moons,
Phobos
and Deimos, are both orbiting around Mars to the right. One of the
moons is going much faster than the other. The slow moon is going
even much slower than Mars is rotating. If one was standing on the
surface of Mars, one would see the faster moon "rising" in the right,
as it would appear to do. At the same time Mars would continue
rotating at the same speed causing it to catch up to the slow moon.
It would continue going faster than the moon causing it to look like
it was "rising" from the left as one stands on the surface of Mars.
This apparant paradox is called relative motion.
>From team 6 at Blessed Sacrament:
Jodi Paci, Robert Yator and Portia Mills
--------------
science@sysnet.net
Organization: Blessed Sacrament
Subject: Challenge Question
I think that the reason that the moons appear to be going oppisite
ways when they are really going the same way is that one moon is
moving faster thatn the other giving the illusion that one is going
back and one is going forward.
By Tim Warren
Deborah Berhane
Virginia Di Tata
Lesley Seidensticker
--------------
science@sysnet.net
Organization: Blessed Sacrament
Subject: challenge question
The moons just appear to be traveling east to west. But they are
really going the same way at the same time.
By Ginny Garayta and Jason Leshner
--------------
science@sysnet.net
Organization: Blessed Sacrament
Subject: Challenge Question #3
A number of things happen to provide this illusion. First, 1 moon is
orbiting around Mars at a greater speed than Mars is rotating. The
other moon is orbiting slower than Mars is rotating.So it seems that
the slower moon is moving in the opposite direction from the faster
moon.
Danny Ross
Chris Hayes
Maureen Andary
Julie Finelli
--------------------
science@sysnet.net
Organization: Blessed Sacrament
Subject: Challange Question #3
Our team thinks that this illusion is caused by the planet Mars
rotating on its axis at slower speed than one moon and the other moon
orbiting around Mars faster than it can rotate.
Mike Minchik
Sarah Reaman
Greg Borsage
---------------------
science@sysnet.net
Organization: Blessed Sacrament
Subject: Challenge Question #3
Each moon is on one side of Mars. Their orbit around Mars is eliptical
so each moon goes around trailing the other. If you are wondering why
you never see one going the other direction is because the orbit of
Mars is faster then the orbits of the moons, making your cite of them
the same all year around.
Alexis B.
Monty B.
Kristen T.
Ezra .D
----------------------
Philip Gressman <102470.1167@compuserve.com>
Subject: Challenge Question #3: Moons of Mars
This situation can be likened to a three man race around a circular
track. From the stands it is easy to see that all three runners are
traveling in the same direction around the track. However, the view
would be quite different for the second place runner. He would see the
first place runner pulling farther and farther ahead while the other
runner lags farther and farther behind and, hence, appearing to be going
in the opposite direction of the lead runner. Mars's angular velocity of
rotation is slightly more than the angular velocity of revolution for
Demos and less than Phobos's velocity of revolution. Therefore, as
Phobos travels slightly faster than Mars rotates, it will appear to "pull
away" and move from west to east. Demos, moving slightly slower than
Mars is rotating, will appear to "lagg behind" or move from east to west.
Philip Gressman, HS Senior from Ava, Missouri
---------------------
Mike_Reynolds_at_CEC001-FA@cc.cranbrook.edu
Subject: challenge question
If a man was standing on Mars and he was looking up at the moons he
would see that Deimos travels from east to west and Phobos travels
from west to east for a few reasons. One that Deimos is farther away
from Mars than Phobos. This means that Phobos revolves around mars a
lot faster than Deimos. But the key is that Phobos also revolves
faster than Mars rotates and Deimos revolves slower than Mars
rotates.
The rotation of Mars is 24.6229 hours, Phobos revolves around Mars in
7.6 hours, and Deimos revolves around Mars in 30 hours. Therefore
Phobos would appear to travel from West to east because it is going
faster than Mars rotates. Deimos would appear to be traveling East to
west because it is going slower than Mars is rotating.
Mike Reynolds - 7th grade science teacher at Cranbrook Kingswood
Middle School, Bloomfield Hills, Mi.
Our response to challenge #3 was sent in by Jerry Trammell, 7th
grade.
------------------------
Darlene Taylor
Subject: Challenge Question #3
We are a MESA class at Dixon Middle
School in Provo, Utah. Our PTK advocate is Mel Twitchell in Utah.
Our answer:
>From Mars the moons are seen to move in opposite directions. This is
because Phobos takes less time to revolve once around the planet Mars
than what Mars takes to rotate on a daily basis. While Deimos takes
a few hours more to revolve.
---------------------
Edward Beidas
Subject: answer to CHALLENGE QUESTION #3
Answer to question #3
Phobos is very close to its planet, Mars. In fact, it is so close
that it takes less time to circle the planet than the planet takes to
revolve on its own axis. This accounts for the moon's rising in the west.
Deimos revolves in a period of time very close to the rotation of Mars.
Therefore, it seems to be rising in the east as does our moon on Earth.
This explains why even though both moons orbit the planet in the
same direction, Phobos seems to rise in the west and Deimos in the east.
PROVISO EAST HIGH SCHOOL
---------------------
Norma L. Barnes
Challenge Question 3
Seventh Grade
Phobos revolves around Mars slower than Mrs rotates and Deimos revolves
around Mars faster than Mars rotates, so phobos appears to be going
backwards.
-----
Eighth Grade
One of Mars's moons, Deimos is faster than Phobos which rotates one-third
as fast as Mars. This gives the illusion that Phobos moves from west to
east while Deimos is further away from Mars, but still moves from east to
west.
Strafford Middle School
Norma L. Barnes
nbarnes@mail.orion.org
-----------------------------
cpeterso@mail.valverde.edu
Maybe one of the moons works like a mirror and it reflects
other things against the sky to make it look like they are
going two different ways.
From Desmond Clark
Both of the moons are going around Mars, but one moon is rotating
right and the other moon is rotating left.
From Joseph Gutierrez
Both moons go the same way, but it looks like they're going separate
ways because one is above the other.
From Jorge Flores
Mead Valley Elementary School in Perris, CA.
Fifth-grade class
Cathy Peterson
----------------------
Date: Fri, 8 Nov 1996 23:23:53 -0800
I put the challenge question up to my space meteorology class. They came
up with:
"There must be a problem between the rotation or mars and revolutions
of the moons." After we made a model using a couple of globes and my
drink container, we decided the backwards moving moon must be revolving
slower than mars rotates, while the normal moving moon must be
revolving faster than mars rotates. Hope this is close. Thanks for
the good opportunity to cause some thinking!
Janet Cook (HS Class)
_____________________
Charlotte Stevens
Subject: Challenge Question #3
I got a variety of responses from my students about the moons of Mars:
Evan writes - "One moon goes fatser than the other so it looks like they
are going in opposite directions, but it is just passing the other moon."
Vera says - "Both of the moons could be moving west to east, but their
orbital route may be off slightly, which makes the moons' track
crisscross. Mars is much smaller than Earth so it separates more on its
track because Mars is more smaller. So if you're standing on the
surface, they look like they're moving in opposite dirctions, but from
Earth it looks like they're moving in the same direction."
Charles' guess - "Because the way Mars moves. I'm guessing Mars moves in
a slanted circulation. So the moons move and crisscross or clash with
each other. The moons also probably move at different speeds."
Caroline states - "Mars' two moons are opposite from each other. Since
Mars is a smaller planet, the curve is more than Earth. If you stand
under one moon going one way you might be able to see the other moon
across the sky going the other way following it."
from Alison - "The planet is making its way around the sun, so as the
planet turns you would think the planets were moving in different
directions. The moons follow each other across the sky. You would see
the moons at different times, going the same way. Or, if you stand on
the North Pole and look one way you'll be watching it go from east to
west, but if you turn around it will appear to go the other way."
Kelly's answer - "Deimos and Phobos, Mars' two moons, travel around Mars'
surface at different distances - one is higher than the other. They both
have their own orbit systems so that way they can't crash into each
other. This is because of Mars' gravity."
Dave,Michael, Sang, Ashish, Marissa and Aracelis all agreed it was the
speed of the moons - "One moon is moving faster than the other moon so it
gets farther and farther away from the other moon, so it looks like they
are going in opposite directions. ...they would in a way follow each
other..one moon is traveling the opposite way that Mars is rotating...Mars
is rotating faster than the speed of the moon orbiting Mars. But it is
also faster than one of the moons. So it seems as if the moon is going
the other way because Mars is spinning faster than one of them."
Charlotte Stevens
8th grade teacher
Taylor Road Middle School
Alpharetta, Georgia USA
-----------------------------
cxtdm@eiu.edu (Tim McCollum)
Subject: Challenge Question
One moon revolves around Mars slower than Mars rotates.The other moon
revolves around Mars faster than Mars rotates.So when you stand on the
surface of Mars you would see one moon move from the east and set in the
west because the rotation of Mars passes the moon.The other moon rises in
the west and sets in the east because it passes up the rotation of
Mars.They are actually going the same direction.
Michael Lawhorn, 8th grade science
Mr. McCollum's class
Charleston Junior High School
Charleston, IL
----------------------------
KEENS%smtpgate@chlais.usc.edu> (Tom Keens )
Subject: Live From Mars - CHALLENGE QUESTION.
Date: Fri Nov 8 17:28:29 1996
CHALLENGE QUESTION:
Mars has two moons, Deimos and Phobos. If you stood on the
surface of Mars and looked up into the night sky, you would see
Deimos slowly travel from east to west across the sky, while
Phobos would be slowly traveling from west to east. In other
words, the two Martian moons travel in opposite directions across
the Martian sky. Yet both moons actually orbit Mars in the same
direction. Explain this paradox.
ANSWER:
I am not an astronomer with ready access to the data to back this
up. However, it would appear that the only explanation would be
that both moons orbit Mars in the same direction as Mars'
rotation. Mars must rotate faster than Phobos, thus it lags
behind your position on the surface of Mars, appearing to move
"backward" (west to east). On the other hand, Mars must rotate
slower than Deimos, thus it gradually gains position relative to
your position on the surface of Mars (east to west).
Thank you.
---Thomas G. Keens, M.D.
Childrens Hospital Los Angeles
-----------------------------
Subject: Challenge Question
Our class reviewed Earths moon and then used students to be Mars and the
two moons and demonstrated their orbits. We also did a one Mars day self
demo by using one hand for Deimos and the other for Phobos and the person
as Mars. If you start Deimos with your right hand extended across your
body to the left and gradually make one complete turn allowing your arm to
only turn 3/4 of the way this simulates Deimos. In the meantime take your
left hand with bent elbow and make three circles around your head to show
Phobos' orbit at the same time. You can see the direction of movement as
Mars. After these exercises students wrote their explanations. This is a
combination of two.
Explanation by Robby Wagner and Emily Hoffman, fifth graders at Lockmar
Elementary, Palm Bay, FL
The reason it looks like one moon is going one way and the other is going
another is their speeds. Phobos goes around Mars very fast in 7.7 hours.
In one Mars day (24.62 hours) Phobos goes around Mars three times. It goes
from west to east. Deimos goes slow (30.3 hours). Deimos is so slow it
looks like it goes east to west. It doesn't go completely around Mars
every day.
Our class really enjoyed this. Thanks.
Mrs. Heine and the Fifth Grade GSP at Lockmar Elementary, Palm Bay, FL
heinee@mail.firn.edu
----------------------------------
John Herrold
Subject: Martian Moon Challenge Question
Re: CHALLENGE QUESTION
I had my ninth grade students respond to the question
regarding the apparent backwards motion of Deimos as seen
from the surface of Mars. Of many entries, these two seem to
be the best!
>From LISA BLAKE:
Planets really move from west to east. Deimos and Phobos may both be
moving slowly but Deimos is moving slower than Mars and Phobos is moving
as fast or faster than Mars. That is why Deimos looks like it is moving
backwards (from east to west ). Deimos's orbit is most likely outside the
orbit of Phobos and that is another reason why it is moving slower( the
orbit is bigger ).
Lisa Blake
EP4
>From MAEVE GLEASON:
Deimos' orbital period is 1.26244 days. Mars rotates on its axis
faster so Deimos appears to move backwards in a retrograde motion from the
Martian surface. On the other hand, Phobos has an orbital period of
0.31891 days which means an observer on Mars would see the moon rise twice
on a single day because it moves much faster than Mars rotates.
Maeve Gleason
EP4
John D. Herrold
Science Department, Grosse Pointe North High School
jherrold@www.science.wayne.edu
-----------------
mhines@aloha.com
Subject: CHALLENGE QUESTION #3 mars moons (fwd)
By way of:
Mark Hines
Mid-Pacific Institute mhines@hawaii.edu
2445 Kaala Street tel (808)-973-5000
Honolulu, HI 96822 fax (808)-973-5099
From: Christi Seto
To: mhines@hawaii.edu
Subject: bonus:mars moons
Hi Mr. Hines
Here's an attempt to explain the movement of Mar's moons.
If Mars is rotating counterclockwise, and Deimos appears to be
moving from east to west across the sky and Phobos appears to be moving
from west to east across the sky when in fact the two moons are going in
the same direction, then it means that Deimos is orbiting Mars at a faster
rate than Mars is rotating and Mars is rotating at a faster rate than
Phobos is orbiting Mars. Therefore, the two moons appear to orbit Mars in
opposite directions when they really aren't.
Christi Seto
From: Arron Yoshida
To: mhines@hawaii.edu
Subject: moons
Wait. I have an improved answer. They are all rotating in the same
direction so maybe one moon travels faster than the rotation Mars and
maybe the other moon travels slower than the rotation of Mars so it would
appear to be going in opposite directions.
-------------------------
stmont01@llwisc.wecb.org (classroom account)
Subject: Challenge #3
To: jwee@mail.arc.nasa.gov
Challenge Question #3: This could happen if one moon is on one
side and the other moon is on the other side of Mars, and then when they
rotate at the same speed they seem to go in opposite directions. Also,
Mars is tilted which allows you to see both moons.
Jake Argo, grade 5, Monticello Schools, Monticello, Wisconsin.