This week we pondered about whether humans would survive sex in space and other challenges, looked at secret plans for a space plane and discovered most of our water came from comets in just some of the stories that came from space this past week. <p>Vote for your top space story of the week:
Building a spaceship to visit another star is hard enough, but keeping the humans onboard alive for the ride may be even harder, space experts said Friday (Sept. 30) in a symposium dedicated to interstellar travel. The challenges of sex and childbirth in space alone are daunting, let alone what happens when the expedition arrives at an alien planet. [<a href="http://www.space.com/13149-space-sex-interstellar-travel-challenges.html">Full Story</a>]
The discovery of intelligent aliens would be mind-blowing in many respects, but it could present a special dilemma for the world's religions, theologians pondering interstellar travel concepts said Saturday (Oct. 1). [<a href="http://www.space.com/13152-aliens-religion-impacts-extraterrestrial-christianity.html">Full Story</a>]
NASA's Dawn mission has revealed that Vesta's southern hemisphere boasts one of the largest mountains in the solar system, and that its surface has striking diversity in its composition, particularly around craters. [<a href="http://www.space.com/13162-asteroid-vesta-giant-mountain-craters.html">Full Story</a>]
If humans ever build an interstellar spaceship —a vehicle capable of reaching another star — one of the biggest questions will be which of the billions of stars in the Milky Way should it visit first? [<a href="http://www.space.com/13165-interstellar-travel-starship-destinations.html">Full Story</a>]
The high atmosphere over the Arctic lost an unprecedented amount of its protective ozone earlier this year, so much that conditions echoed the infamous ozone hole that forms annually over the opposite side of the planet, the Antarctic, scientists say. [<a href="http://www.space.com/13157-arctic-ozone-hole.html">Full Story</a>]
The biggest obstacle to deflecting a killer asteroid may be humanity's inability to work together, experts said at a presentation in Pasadena last week. [<a href="http://www.space.com/13164-killer-asteroids-deflection-humanity-cooperation.html">Full Story</a>]
NASA is seeking applicants for its next astronaut class, spaceflyers who could fly in low-Earth orbit and beyond. [<a href="http://www.space.com/13169-nasa-astronauts-wanted-deep-space-travelers.html">Full Story</a>]
For the three astrophysicists who won the Nobel Prize in physics today (Oct. 4), it was only a matter of when, not if, they would get the prize, their peers said. Their discovery that the universe's expansion is accelerating was an Earth-shattering revelation that led to the bizarre concept of dark energy. [<a href="http://www.space.com/13177-nobel-prize-accelerating-universe-dark-energy-reaction.html">Full Story</a>]
A new study finds that the water in comet Hartley 2 is nearly exactly the same type as that found in Earth's oceans, suggesting that most of our planet's water came from comets and not asteroids, astronomers say. [<a href="http://www.space.com/13185-comets-water-earth-oceans-source.html">Full Story</a>]
The maker of the X-37B robotic space plane has outlined new plans for the craft and a scaled-up version to support space station cargo deliveries or even carry astronauts into orbit. [<a href="http://www.space.com/13230-secretive-37b-space-plane-future-astronauts.html">Full Story</a>]
