What country helped Apollo 13?

What does parallax error mean? What are two main bodies in terms of mass in your solar system? Betelgeuse and rigel are stars in which constellation? Which object can never be seen in an opposite direction in the sky from the sun? How big is the gherkin? How long does it take light to travel from the sun and the earth? Did Sally Ride found Sally Ride Science in 2001? What is the purpose of the rocket ships? What happens if the moons shadow falls on the Earth? What do instruments on the moon measure? What are the three brightest stars in the sky? How many stars would you have to search before you would expect to hear a signal? Are cumulonimbus clouds white or gray? How long does it take to hatch a moon dragon on dragonval? Why is Mars called the red plenet? What event marked beginning of the Atomic Age? Does the sun contain homeostasis? The Voyager 1 spacecraft is currently about 18.5 billion km from the Earth. How long does it take in seconds for a radio signal to get from Voyager 1 to Earth? Which planet is called yellow planet? Who was the second person to set foot on the moon and when?