Rosetta just did an extreme maneuver to get closer than we ever have to a comet - and came back wih incredible pictures

The European Space Agency's Rosetta spacecraft came close enough to almost kiss a comet on Valentine's Day this year.

In fact, it was the closest that Rosetta has ever and will ever get to Comet 67P/Churyumov-Gerasimenko. The event marks the beginning of a new phase in Rosetta's mission.

On February 14, the spacecraft came to within 3.7 miles of the comet's surface - 10 times closer than when Rosetta closed in on its target last year to deploy the Philae probe, which is the first probe to ever soft land on a comet making history when it did on November 12.

This time around Rosetta's NAVCAM instrument took over a dozen close-up shots of the comet's arresting surface features - and they are some of the best photos we've ever seen.

Rosetta began prepping for closest approach on February 4 when it fired its thrusters to break course from its current flight path. This is what Rosetta saw a couple of days later, on February 6, from 77 miles away:

Over the next 10 days, the spacecraft performed a series of extreme flight maneuvers (shown in the gif below) to line itself up for the close encounter that would take it past the larger of the two lobes.

On February 9, the spacecraft had moved slightly closer but was still 65 miles away.

The comet is 100 million times more massive than the International Space Station, traveling 40 times faster than a speeding bullet, and spitting out jets of dust and debris, but that didn't stop ESA scientists from getting a closer look.

Between February 11 and 14, Rosetta headed straight for its target, closing a distance of almost 60 miles in just three days.

Below is a montage of four up-close-and-personal images of the comet's rocky, uneven surface. These four photos were taken when Rosetta was 7.8 miles above the surface.

Just hours later, Rosetta took this image from 5.5 miles away:

But the most incredible photos of all are the ones the spacecraft captured from a mere 3.7 miles above the surface.

To help you orient yourself, these images are of the region of the comet called Imhotep, outlined in red at the bottom of the diagram below:

The set of images below are the closest shot a spacecraft has ever snapped of a comet.

The largest boulder in the upper right corner of this first extreme close-up is about 150 feet across and goes by the name Cheops. Check out the stark contrast in smooth and rough patches on the surface as well as the many scattered boulders.

Rosetta's comet is covered with dust and jagged edges. The dust on the comet has built up over time creating a layering effect, indicated by distinct lines in the upper left corner in the image below.

Scientists are not certain of how Rosetta's comet got that iconic but bizarre dumbbell shape. The two leading theories are: The comet was once more spherical but jets eroded away certain sections faster than others. Or, two smaller, separate bodies smashed and welded together. The fractures and layers in the comet, like the ones shown in the image below, has some scientists thinking that the comet formed by the latter method.

It's shocking to see such detail in a picture like this of an object that is more than 300 million miles from Earth - more than three times farther than the sun.

More science

The close flyby took place over the comet's most active regions, which made the event particularly exciting for scientists.

"The upcoming close flyby will allow unique scientific observations, providing us with high-resolution measurements of the surface over a range of wavelengths and giving us the opportunity to sample - taste or sniff - the very innermost parts of the comet's atmosphere," said Matt Taylor, ESA's Rosetta project scientist, in an ESA statement released shortly before the close approach.

Last month, the ESA researchers working on Rosetta published a series of papers on the data it had collected in the months since it deployed Philae. One of the important discoveries they found was that the water on the comet did not match the water on Earth, discouraging the theory that comets brought water, that eventually cultivated life, to our planet.

There are still questions that need answers, like what is spitting jets of debris from the comet into space. Rosetta's close flybys are important to help scientists understand this, which is why the spacecraft has now entered a new phase of maneuvers that it will perform over the next few months.

As the comet travels closer to the sun - reaching it's closest approach on August 13 this year - it will grow increasingly more active, spewing out more debris. Therefore, over the next few months, Rosetta will be making repeated close flybys of the comet to collect as much information as it can about the comet's atmosphere - but never one as close as the one it just completed.

The only chance we have for pictures as spectacular as the ones above is if the Philae spacelander wakes up from hibernation, which Rosetta flight director, Andrea Accomazzo hopes could be this June or July.

Check out the video below about the next phase in Rosetta's life and what else scientists hope to learn: