Mariner2 - Blog Posts

Solar System: Things to Know This Week

Go for Venus! Fifty-five years ago this week, Mariner 2, the first fully successful mission to explore another planet launched from Cape Canaveral in Florida. Here are 10 things to know about Mariner 2.

1. Interplanetary Cruise 

On August 27, 1962, Mariner 2 launched on a three and a half month journey to Venus. The little spacecraft flew within 22,000 miles (about 35,000 kilometers) of the planet. 

2. Quick Study 

Mariner 2's scan of Venus lasted only 42 minutes. And, like most of our visits to new places, the mission rewrote the books on what we know about Earth's sister planet.

3. Hot Planet 

The spacecraft showed that surface temperature on Venus was hot enough to melt lead: at least 797 degrees Fahrenheit (425 degrees Celsius) on both the day and night sides.

4. Continuous Clouds 

The clouds that make Venus shine so bright in Earth's skies are dozens of miles thick and permanent. It's always cloudy on Venus, and the thick clouds trap heat - contributing to a runaway "greenhouse effect."

5. Night Light 

Those clouds are why Venus shines so brightly in Earth's night sky. The clouds reflect and scatter sunlight, making Venus second only to our Moon in celestial brightness.

6. Under Pressure 

Venus' clouds also create crushing pressure. Mariner 2's scan revealed pressure on the surface of Venus is equal to pressure thousands of feet under Earth's deepest oceans.

7. Slow Turn 

Mariner 2 found Venus rotates very slowly, and in the opposite direction of most planets in our solar system.

8. Space Travel Is Tough 

Mariner 2 was a remarkable accomplishment, considering that in 1962 engineers were still in the very early stages of figuring out how operate spacecraft beyond Earth orbit. The first five interplanetary missions launched - by the U.S. and Soviet Union, the only two spacefaring nations at the time - were unsuccessful.

9. Not Ready for Its Close Up 

Mariner 2 carried no cameras. The first close-up pictures of Venus came from NASA's Mariner 10 in 1974.  

10. Hot Shot 

The first (and still incredibly rare) photo of the surface of Venus was taken by the Soviet Venera 9 lander, which survived for a little more than a minute under the crushing pressure and intense heat on the ground.

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