(1) Its tails allows us to probe the physics of the interaction between an isolated neutron star and the interstellar medium.

(2) The Earth sits in a stream of accelerated particles coming in from the Sun, interstellar material, and galactic sources.

(3) This propulsion concept could be used as the engine for an interstellar probe.

(4) He added that interstellar travel - between solar systems - was far less likely.

(5) When we've colonized space and mastered interstellar travel, can there even be sci-fi anymore?

(6) The solar system formed 4.6 billion years ago from an interstellar cloud of gas and dust.

(7) Very few species had achieved interstellar travel at this time in the Galaxy.

(8) Come on, did you suspect that the smell of rotten eggs might one day lead to practical interstellar space travel?

(9) On the other hand, there are ways to reach other civilizations without interstellar travel.

(10) We just had to plan for interstellar travel if we were ever to encounter really interesting planets with intelligent beings.

(11) Most will crash into the Sun, strike another planet, or be flung by Jupiter's gravity into interstellar space.

(12) Astronomers want to know how much of the dust in the Solar System is shed by comets and asteroids, and how much comes directly from interstellar space.

(13) Orion is home to the famous Orion nebula, a glowing cloud of interstellar gas where new stars are being born.

(14) Technologies based on resources drawn from all over the Solar System will make interstellar trips affordable.

(15) They may not exit the comet clouds and into proper interstellar space for up to another 40,000 years after that.

(16) Some scientists tend to scoff at the idea of interstellar travel because of the enormous distances that separate the stars.

(17) Instead, they could be interstellar rovers captured by the Sun's gravity.

(18) The Sun and most of the Solar System are bathed in a huge cloud of interstellar hydrogen.

(19) The greatest challenge of interstellar travel is the enormous distances between stars.

(20) More dark clouds of interstellar dust with intriguing shapes are seen silhouetted against the glowing interstellar gas at the top right.