This is it. Curiosity has reached its prime destination. After a brilliant conception, an amazing landing, and two years of continuous travel, the rover is now at the base of Aeolis Mons -- aka Mount Sharp -- a mountain that rises 5.5km at the center of Gale Crater. This is where the real fun begins.
Mount Sharp was chosen by NASA because it's unique geological features will give us an extensive look into the history of the Red Planet. It's also a place that may show traces of extinct biological life.
Curiosity's trek up the mountain will begin with an examination of the mountain's lower slopes. The rover is starting this process at an entry point near an outcrop called Pahrump Hills, rather than continuing on to the previously-planned, further entry point known as Murray Buttes. Both entry points lay along a boundary where the southern base layer of the mountain meets crater-floor deposits washed down from the crater's northern rim.
NASA changed Curiosity's planned course after understanding the area better, according to Curiosity Project Scientist John Grotzinger at CalTech in Pasadena, California:
It has been a long but historic journey to this Martian mountain. The nature of the terrain at Pahrump Hills and just beyond it is a better place than Murray Buttes to learn about the significance of this contact. The exposures at the contact are better due to greater topographic relief.
This is it: Amargosa Valley, "the slopes leading up to Mount Sharp on Mars. The rover is headed toward the Pahrump Hills outcrop, seen above the scale bar. This area represents a boundary between the plains of Gale Crater, named Aeolis Palus, and the layered slopes of Mount Sharp, or Aeolis Mons. Curiosity has recently crossed into this terrain and now is on the Mount Sharp side of the transition zone."
Every time I read about this mission, I sit for a while thinking about Curiosity alone in Mars. I close my eyes and picture it moving slowly, its cameras looking around while the Martian breeze caresses its chassis. I can imagine the slow mechanical noises, the wind, and cracking sound of the sand and rocks under its wheels. I really wish I were there.
Godspeed, buddy. Your journey is not over yet.