Questions mark the beginning of every space science journey. So if you've
ever wondered why, where, what, who or how — click the "Ask A Question"
button below to find out from the Athena Mission scientists. Read on
to discover what other kids have found out!
1) Why are Martian volcanoes dormant?
When planets form they are initially very hot, hot enough to melt rocks
in their interiors. Over time, planets lose heat through their surfaces
to space. This is sort of like a hot pie cooling on a window sill. If
the planet is small, like the moon or Mars, eventually all the heat is
lost and the planet stops having active volcanoes. The Earth, which is
much bigger, still has enough heat in the core to drive plate tectonics
and keep volcanoes busily erupting.
2) Is it possible to create a better atmosphere around Mars by setting
off a volcano? If so, how?
While this was an interesting idea in that Arnold Schwarzenegger movie,
it was really just science fiction. Volcanoes themselves don't spew out
enough gas in an eruption to actually add enough material to make the
atmosphere thicker in a short time. At the peak of an eruption in
Hawaii, a volcano puts out around 2000 tons of gas. Now that sounds
like a lot, but the total Earth atmosphere is around
5,000,000,000,000,000 tons, or more than a trillion times more massive
than that! The Hawaiian volcano would have to erupt at that rate every
day for 7 billion years to make the whole Earth atmosphere. Since Earth
is only 4.5 billion years old, volcanoes aren't a good way to make a new
atmosphere. For more volcano facts you can visit the
USGS web site.
3) How long does it take light from the Sun to get to Mars?
On average in its orbit, Mars is about 228,000,000,000 meters away from
the sun (that's 2.28 x 1011 m in scientific notation). Light travels at
300,000,000 meters/second (3x 108 m/s). To get the answer, divide the
distance by the speed. You'll find that it takes 760 seconds, or 12
minutes and 40 seconds for sunlight to reach Mars. It takes light about
8 minutes to travel from the Sun to Earth.
4) What experiments have been done to find out if there is life on Mars?
There were a number of experiments on the 1976 Viking landers that were
designed to see if there was life on the surface. There were a series
of biology experiments to see if Mars soil showed activity when combined
with water or biological nutrient solutions. There was also an
instrument called a gas chromatograph-mass spectrometer (GCMS) to search
for organic compounds. The GCMS showed no organic compounds at the part
per billion level, and it is widely accepted that the reaction of Mars
soils to water or nutrient solutions is related to chemical activity
rather than biology. Future experiments, including those to be
performed by the Athena science payload on MER, will focus on the
possibility of past or fossil life. The British will also attempt to
place a lander on Mars in 2004,
the Beagle 2.
Beagle 2 has similar capabilities to Viking,
with a mass spectrometer for evolved gasses and detection of carbon in
soils.
5) Who invented the Athena rover?
The Athena rover was not the invention of a single person, but of a
whole team of engineers focused on how to move around on other planets.
The design incorporates mechanical and mobility systems, electrical
connections, radio communications, each of which has a sub team
responsible for a portion of the whole system. The design builds on the
heritage of some systems from the Sojourner rover which landed in 1997.
You can find out more about the rovers components on
this site and on the
MER
website. You
can also try the current
JPL program in
planetary robots and an archived page on the different
Sojourner
sub-systems.
6) What kind of scientists do we need on Mars and why?
Mars is a dynamic planet, like the Earth. To understand the history and
evolution of the surface, interior and atmosphere we need scientists that
specialize in geology, physics, chemistry and the combinations of those basic
fields. If people ever live on Mars we will need additional skills like
medicine and engineering, similar to astronauts on the Space Station, or
scientists that "winter over" in
Antarctica.
Each person that goes must have several areas of expertise, and they have to be
able to solve any problem that comes up, as help is very far away and takes a
long time to get there.
7) What type of work will people do when they live on Mars?
I imagine they will mostly be preoccupied with the business of living. Making
fuel or food, energy for lights and power, a little bit of science to understand
the planet or how to make the "life-support" systems more efficient. While they
could operate from delivered supplies, the time and distance involved will
require that a Mars community become self-sustaining fairly quickly. Think
about if you wanted to build a house on Mars. How would you power the lights?
Where would you get things to eat? Where would the water come from to drink?
If you wanted to throw something away and there was no trash man to pick it up
where would it end up? How much could you recycle or reuse? What if you got
sick or hurt? These basic requirements for living we take for granted here,
but they are the center of activity for a Mars community.
8) Is colonization of life on Mars a realistic possibility?
I believe that we have the technical and creative ability required to build
sustained colonies on Mars. The difficulties arise in finding the money (it
will be very expensive) for a long period of time. Similar to sending men to
the moon, sending people to Mars will take a decade or more of focused
development and incremental technological steps. I think the effort will
require us to work with other countries in strong collaboration as a goal for
humanity, not just the United States. The biggest hurdle is finding a
compelling reason "why go?", why spend all that money, when people are out of
work, or the country is in debt, or the highways need to be fixed.
9) After the rovers, what is the next mission to Mars?
There are two more planned missions, an orbiter to launch in 2005 and another
rover in 2009. The 2005 orbiter will study the climate and map the surface and
the 2009 rover will be much more capable than our 2003 rovers. The 2009 rover
will be the first step in returning a piece of rock from the Martian surface.
There is also a small mission in 2007, called Scout, and there are 4 competing
ideas for what to do at that launch opportunity. NASA will pick one Scout in the
summer of 2003.
10) Why did you want to become a scientist?
When I was young I didn't have a clear idea what I wanted to be. I was good at
math and science and had some very good teachers that made it fun and interesting.
I was also something of a misfit, not willing to be stupid just to go along with
the crowd. In high school I did a lot of theater, acting, backstage work, it was
a good crowd for misfits and I felt really welcome in that group. When I got to
college I tried to do both, taking math and physics classes and volunteering
backstage for the theater performances. Eventually I had to make a choice as I
didn't have time to do everything. In part I chose science because I thought I
would get a better job, but also college theater was dominated by everyone's
desire to be a big star and I found I had more like-minded friends among the
science crowd. I have always liked the "hands-on" element. I helped my father
build a stereo and a television. I liked building and painting theater sets. I
loved my physics labs where we had all kinds of ancient equipment from
spectroscopes and oscilloscopes to real basics, some magnets and wire. In my
current job I emphasize field and lab work to back up remote data sets. It is
difficult to be "hands on" as a planetary scientist, but being part of the
missions is close. We'll be actively deciding where to go and what to do with
the rovers on a day by day basis and I'm really excited that my decision, more
than 20 years ago, has lead to being on the MER team.
