For 15 years now, NASA has been putting out an Astronomy Picture of the Day, picking whatever hits their fancy from the archives or new stuff coming in from up above.

Here are ten of the best they posted this year.

10. Atlantis takes off

In the early morning hours of July 12, 2001, the shuttle Atlantis takes off to visit the International Space Station.

9. The Darks Sands of Mars

Trees on Mars? Not exactly. Dark sand is cascading down lighter pink sand in this photo near the north pole of Mars.

8. The Space Station Cruises Along

The International Space Station, as seen from above.

7. Giant Dust Pillars

A star is being born inside that dustpillar, which measures a light-year in length. The bright pink spots outside are stars that have already been birthed.

6. Saturn Moons, Passing Each Other

The big moon here is Rhea, caught here passing Epimetheus, one of Saturn's smaller moons. You can see the rings, and the background is the planet itself. 5. When Galaxies Collide!!

Two galaxies go in, only one comes out. The stars in the galaxies tend not to collide, because there's so much space between them, but the gravitational forces can still be a bitch.

4. The Plains of Mars, as the Rover Sees Them

The rover Opportunity looks out over the dark sand and bright rock of Mars' plains. It's moving towards a crater, moving about a football-field length each day.

3. Here Comes the Sun Explosion

Wow. Now we know why the Polish Space Agency only lands on the sun at night.

2. A Moon of Mars

Phobos, the larger of Mars' two moons. The Russians are landing a probe on it next year.

1. An Icy Comet

The nucleus of the Comet Halley, about nine miles across.