NOVA Online: Hunt for Alien Worlds (see bottom of page for navigation)
Worlds sidebar (see bottom of page for navigation)

JupiterCongratulations. You found Jupiter. With its famous red spot, Jupiter is the most massive planet in the solar system. (It is more than 300 times more massive than the Earth.) Jupiter is a gas planet, which means it has no surface to walk on. Jupiter's outer layers consist mostly of hydrogen and helium. The planet has been visited by six spacecraft, the first one being Pioneer 10 in 1973.

OK, now that you've found and photographed Jupiter, it's time to look at the other four planets nearby and see if any of them can support human life. The planet you're looking for needs to have moderate temperatures and liquid water. Your instruments are showing you the readings below. Which one might be habitable?

Planet E Planet F Planet G Planet H
Mass (kg) 4.87 x 1024 6.42 x 1023 5.98 x 1024 3.3 x 1023
Mean surface temperature (K) 726 310 281 452
Atmosphere 96.5% carbon dioxide
3.5% nitrogen
95.3% carbon dioxide
2.7% nitrogen
1.6% argon
0.15% oxygen
trace amouts of water
78% nitrogen
21% oxygen
1% argon
trace amount of carbon dioxide and water
no atmosphere
Satellites 0 2 1 0

Back to Readings

Photo courtesy NASA

Worlds Home | Alone? | Stargazer
Constellations | Star Map | Planets
Life | Resources | Table of Contents

Support provided by

For new content
visit the redesigned
NOVA site

NOVA Home | WGBH Home | PBS Home
Search | Feedback | Shop | Printable Page
© 1997 WGBH