(Image source: NASA)

BY: STEVEN SPARKMAN

A mission to study the largest asteroids in our solar system is about to reach its first target. CNN has more.

“This is an asteroid called Vesta, and in just a matter of days, on July 16, a U.S. spacecraft -- the Dawn -- is expected to arrive at it’s orbit around this asteroid. Now, what’s so cool about this -- why I’m showing it to you -- you can see this thing in the night sky. It’s the only asteroid that is visible to the naked eye, and it’s only this month and next.”

The Dawn probe has spent four years flying through space to get to this point.

The plan is to spend about a year each orbiting the two largest objects in the asteroid belt -- first Vesta, then Ceres. The goal is to use these two very different asteroids to understand more about the early days of the solar system. (Video source: NASA / Wired)

Since mid-June, NASA has been releasing snapshots from Dawn as it got closer and closer to Vesta.

The latest shots, like this one from July 9, show the asteroid in so much detail, astronomers like Discover Magazine’s Phil Plait are already speculating on what the mission will learn. (Image source: NASA)

“Vesta is … peppered with impact craters, as expected. It may just be the lighting, but they look shallower than I would’ve thought. Sometimes that happens when the impacted body is soft, like ice or loosely packed material -- though we know the surface is rocky. Maybe it’s powdery, like the Moon’s surface?”

The Dawn probe itself is a record-setting spacecraft. It’s the first to use ion propulsion technology. Basically, it uses sunlight to charge gas particles that give it a slow-but-steady forward push. The Guardian quotes one of the propulsion scientists saying -- that slow push adds up over four years.

"If you integrate that over all the hours it's doing it, it ends up being a much greater velocity change than you could get from the same quantity of chemicals … It's accelerating with patience."

Dawn will set another record when it leaves Vesta to head for Ceres, becoming the first probe to go from one non-Earth orbit to another.