Download Click on Venus

A Tour of the Solar System – Webquest
Answer Key
Use the website to complete this activity.
http://solarsystem.nasa.gov/planets/index.cfm
Click on Venus
1. Is it likely life could ever evolve on Venus? Explain.
No evidence for life has been found on Venus. The planet's extreme high temperatures of almost 480
degrees Celsius (900 degrees Fahrenheit) make it seem an unlikely place for for life as we know it.
2. Describe the European Space Agency’s Venus Express Mission.
Venus Express has completed routine science observations and is preparing for a daring plunge into
the planet's hostile atmosphere.
3. What is unusual about the rotation of Venus?
Venus spins backwards (retrograde rotation) when compared to the other planets. This means that
the sun rises in the west and sets in the east on Venus.
4. How does a day on Venus compare to a year on Venus?
One day on Venus lasts as long as 243 Earth days (the time it takes for Venus to rotate or spin once).
Venus makes a complete orbit around the sun (a year in Venusian time) in 225 Earth days. It orbits the
sun faster than it rotates on it’s own axis.
5. Describe the atmosphere of Venus.
Venus' thick and toxic atmosphere is made up mostly of carbon dioxide (CO2) and nitrogen (N2), with
clouds of sulfuric acid (H2SO4) droplets.
6. Describe the ‘greenhouse effect” that exists on Venus.
The thick atmosphere traps the sun's heat, resulting in surface temperatures higher than 470 degrees
Celsius (880 degrees Fahrenheit). The few probes that have landed on Venus have not survived longer
than 2 hours in the intense heat.
7. How has volcanic activity shaped the landscape of Venus?
Craters smaller than 1.5 to 2 kilometers (0.9 to 1.2 miles) across do not exist on Venus, because small
meteors burn up in the dense atmosphere before they can reach the surface. It is thought that Venus
was completely resurfaced by volcanic activity 300 to 500 million years ago. More than 1,000
volcanoes or volcanic centers larger than 20 kilometers (12 miles) in diameter dot the surface.
Volcanic flows have produced long, sinuous channels extending for hundreds of kilometers.
8. What is the significance of the Soviet Union's Venera 7?
Venera 7 was the first spacecraft to transmit data from the surface of any extraterrestrial planet,
though its success was uncertain at first. The probe sent data to Earth for 35 minutes while falling
through the atmosphere, but the data transmission appeared to be replaced by noise as soon as the
capsule hit the ground. Computer processing revealed, however, that this noise contained nearly 23
minutes of additional information at 1 percent of normal signal strength. The transmitted data
indicated a surface temperature of 475 give or take 20 degrees Celsius and a pressure of 90 give or
take 15 atmospheres.
9. Why is it so difficult to get accurate information from the surface of Venus?
We cannot normally see through Venus' thick atmosphere and the intense heat prevents probes from
surviving for long periods of time.
10. What is the origin of Venus’ name? Why is the name appropriate?
Venus is named for the ancient Roman goddess of love and beauty.
11. How does surface gravity on Venus compare to earth?
If you weigh 100 pounds on Earth, you would weigh 91 pounds on Venus.
Click on Earth
1. The Earth’s seasons are a result of what phenomenon?
The four seasons are a result of Earth's axis of rotation being tilted 23.45o with respect to the plane of
Earth's orbit around the sun. During part of the year, the northern hemisphere is tilted toward the sun
and the southern hemisphere is tilted away, producing summer in the north and winter in the south.
Six months later, the situation is reversed. When spring and fall begin, both hemispheres receive
roughly equal amounts of solar illumination.
2. The oceans, which cover roughly 70% of the planet, have an average depth of
4 kilometers
3. Besides being responsible for our weather, our atmosphere serves another valuable purpose.
Describe it.
The atmosphere affects Earth's long-term climate and short-term local weather, shields us from much
of the harmful radiation coming from the sun, and protects us from meteors as well - most of which
burn up before they can strike the surface as meteorites.
4. Which two elements make up about 99% of our atmosphere?
78 percent nitrogen, 21 percent oxygen
5. What conditions give rise to the Earth’s magnetic field?
Our planet's rapid rotation and molten nickel-iron core give rise to a magnetic field.
6. What causes the northern and southern lights?
When charged particles from the solar wind become trapped in Earth's magnetic field, they collide
with air molecules above our planet's magnetic poles. These air molecules then begin to glow, and are
known as the aurorae - the northern and southern lights.
7. Describe the Theory of Plate Tectonics
Earth's lithosphere, which includes the crust (both continental and oceanic) and the upper mantle, is
divided into huge plates that are constantly moving. Earthquakes result when plates grind past one
another, ride up over one another, collide to make mountains, or split and separate.
8. What are the temperature extremes of planet earth?
-88/58 (min/max) °C
Click on Mars
1. Why is it unlikely liquid water exists on Mars?
Its atmosphere is too thin for liquid water to exist for long on the surface.
2. How does water exist on Mars?
Evidence for water now exists mainly in icy soil and thin clouds.
3. What is the primary mission of Curiosity? When is it scheduled to land?
Investigate whether conditions have been favorable for microbial life and for preserving clues in the
rocks about possible past life. 6 Aug 2012:
4. When did we get our first close‐up glimpse of the surface of Mars?
When the Mariner 4 spacecraft flew by Mars in 1965, photographs of a bleak, cratered surface
shocked many - Mars seemed to be a dead planet.
5. What factors contribute to Mars appearing red?
Iron minerals in the Martian soil oxidize, or rust, causing the soil -- and the dusty atmosphere -- to
look red.
6. Why do scientists theorize the two moons of Mars – Phobos and Deimos might be captured
asteroids?
Potato-shaped, they have too little mass for gravity to make them spherical. Phobos, the innermost
moon, is heavily cratered, with deep grooves on its surface.
7. What observations have led scientists to believe the climate has changed over time on Mars?
The polar ice caps on Mars grow and recede with the seasons. Layered areas near the poles suggest
that the planet's climate has changed more than once. Volcanism in the highlands and plains was
active more than 3 billion years ago.
8. The 2002 Mars Odyssey made some intriguing observations. Describe them.
In 2002, NASA's Mars Odyssey orbiter detected hydrogen-rich polar deposits, indicating large
quantities of water ice close to the surface. Further observations found hydrogen in other areas as
well. If water ice permeated the entire planet, Mars could have substantial subsurface layers of frozen
water.
9. NASA’s Phoenix observed a weather phenomenon similar to what we experience on Earth. What was
it?
In 2008, NASA's Phoenix Mars lander was the first mission to touch water ice in the Martian arctic.
Phoenix also observed precipitation (snow falling from clouds).
10. How do the minimum/maximum temperatures on Mars compare to Earth’s temperatures?
-153 to +20 °C – Much colder at night, but relatively similar temperatures during the day.
11. Mars has some spectacular geologic features, including volcanoes and canyons. What are the names
of the massive volcano, and canyon system?
Mars has the largest volcano in the solar system, Olympus Mons, as well as a spectacular equatorial
canyon system, Valles Marineris.