@stro object for the week of 03/27/2000
courtesy of STSCI
planet Mars gets its name from the Roman god of war. Mars is the
fourth planet from the Sun and is one of the "terrestrial
planets". Mars has a reddish hue brought about by the high
amount of iron oxide (rust) in its soil and the dust in its atmosphere.
Mars is easily
visible with the naked eye when viewable from Earth and has been
known about for countless millennia. Our understanding of the nature
of Mars has made leaps and bounds since it was announced by nineteenth
century astronomer Percival Lowell that Mars had water canals which
crossed its surface and subsequent claims by others that Mars was
a lush paradise with intelligent life. Lowell was incorrect - there
are no water flows on Mars today, but there is evidence of past
water flows and floods in the form of the erosion the water left
to be the focus of intense research and the recipient of several
spaceprobes beginning with Mariner 4 in 1965. These probes have
beamed back information about this mysterious planet, but many questions
still remain. Most notable of these questions is whether there was
ever past, or even present, life on the planet. Space travel to
Mars, like the other planets, remains fairly treacherous and far
from routine as evidenced by the failure of two of the most recent
of these Martian spaceprobe missions, NASA's Mars
Polar Lander and Mars Climate Orbiter missions. There have been
some spectacular successes however, such as the Mars Pathfinder
rover and the Mars Global Surveyor missions. Other missions to Mars
are in development including a plan to return Martian soil to Earth
for analysis. Human spaceflight to Mars remains a goal that many
world space agencies envision, even possibly within the next two
Some other interesting
facts about Mars:
- Martian geology
has produced some interesting features on Mars, such as Olympus
Mons, which is the largest known mountain in the solar system,
and the infamous "Face on Mars" that has since turned
out to be just another eroded plateau in better images provided
by Mars Global Surveyor.
- Mars has
a diameter of 6794 kilometers (4221 miles) compared to Earth's
12756 km (7926 mi). However, the Martian land surface area is
equivalent to Earth's since there is no ocean water to submerge
- Mars has
two moons named Phobos and Deimos.
- It has permanent
polar ice packs.
- The Martian
surface shows clear signs that wind and water related erosion
has taken place. Present day erosion is caused by wind.
- Mars has
radical climate temperature differences spurred on by an elliptical
orbit around the Sun, among other things. This elliptical orbit
produces a temperature variation as high as 30 Celsius (86 Fahrenheit).
While Mars does have a thin cloud layer it lacks a thick atmosphere
to hold in and regulate heat. Although the average temperature
is around -55 C (-67 F) it can vary on the planet from -133 C
(-207 F) at the poles to 27 C (80 F) on a summer day.
information for Mars (North America):
info from SEDS...
of Martian cloud formations from STSCI...
info on the Mars Pathfinder Rover mission...
info on the Mars Global Surveyor...