It's been over five decades since Edward White, an American astronaut from San Antonio, became the first man to "walk" in space on June 3, 1965. Traveling at speeds in excess of 17,000 MPH, White stepped out from his Gemini 4 capsule and instantly became a part of history. To celebrate this landmark event, test your space knowledge with our trivia questions...
What Does Outer Space Sound Like? A whole lot of...nothing. If you've ever seen the movie Alien, then you probably remember the tagline: "In space, no one can hear you scream." And for the most part, that's true. Sound waves need a medium to travel through—like Earth's atmosphere—in order to be heard. Because Space lacks an atmosphere of its own, the universe is silent. Astronauts can communicate with each other because radio waves do not require the same atmospheric medium to move about.
How Many Stars Are in the Observable Universe? Astronomers have no way of knowing for sure how many stars are out there. To put it in perspective, it would take over 6,000 years just to count the stars in our galaxy, so any figure stating the number of stars in the universe is a guess...at best. Notice that the question also asks about the "observable" universe. Because The Big Bang happened about 13.7 billion years old, we can only see stars within 13.7 billion light-years from us. Who knows how many are out there in the yet-to-be-explored universe! With all that in mind, the best estimates for stars in our observable universe hover around 1,000,000,000,000,000,000,000. Basically, the calculation goes like this: The Milky Way has about 100 billion stars, and there are about 10 billion galaxies in the observable universe. Assume most galaxies have about the same number of stars and you arrive at that figure.
How Long Will the Astronauts' Footprints Last on the Moon? When you step in some mud, that footprint probably washes away within a few days. But on the moon, there's no atmosphere—and therefore no wind or rain—to erode the footprints left by the 12 astronauts who have walked on the moon. They won't be there forever, though. The moon is constantly coming in contact with heavenly bodies like "micrometeorites" that will slowly, over about 100 million years, erase the history of NASA's moon exploration.
When Will the Sun Burn Out? Next year! Just kidding...you've got plenty of time—5 billion years, in fact—before the sun turns into a red giant and engulfs our planet. So far, the star that powers our solar system has burned about half of its hydrogen reserves, which is impressive considering the star converts about 600 million tons of hydrogen into energy per second. But beware: living creatures will likely need to high-tail it off the planet long before we get eaten up by the sun. Within the next billion years, the sun will grow so large it will boil our oceans and make Earth uninhabitable.