I couldn't let 2015 go without recapping my top science stories of the year! There were three standouts to me in 2015. As always, these are my personal choices, so this is a completely biased ranking. You have been warned.
3. Paris Climate Agreement
In an agreement that was better than expected--though not quite enough, scientifically speaking--the nations of the world promised to try and keep global temperatures from rising more than 1.5 degrees Celsius. Accountability is still shaky, but the U.N. agreement does state that nations must report their progress every five years.
Mayors from hundreds of cities pledged that by 2050, they would run their towns only through renewable energy. This will give a much-needed economic push to the renewable energy industries. But the reality is that fossil fuels remain the cheaper option unless nations move to tax them, which is unlikely.
The moral of the story is that the Paris Summit was a major step in the right direction, though naturally more steps are needed. I'm choosing to look on the bright side, though. Every journey takes many steps, so as long as we're walking forward, that's better than standing stubbornly still.
2. New Horizons Reaches Pluto
People might be surprised that this isn't my number one, and I admit it was a close call.
On July 14th, New Horizons flew past Pluto, going faster than any man-made object in existence. It took nine years to get out to the Kuiper Belt, where Pluto is located at the edge of our solar system, and collected a wealth of knowledge in a matter of hours--including our first ever up-close pictures of Pluto!
Scientists are learning a bunch from this mission, but my favorite thing about it was how excited it got the public about space exploration. Everyone loves Pluto, and when we finally got to "meet" the dwarf planet this year for the first time, we learned Pluto loves us, too! The big heart-shape is a plain of frozen glacial nitrogen, brilliantly reflecting sunlight from three and a half billion miles away. How cool! Literally!
As for my number one science story of the year...
1. HOMO NALEDI!!!
Sorry, space. The paleoanthropologist in me wins out this year.
This story had ME written all over it. A new relative of ancient humans. Cool caves. A team of all-lady scientists. Live-tweets (and blogs!) of the discovery. And more fossils than can yet even be COUNTED.
Yes, the discovery and publication of Homo naledi is my number one story of 2015. The Rising Star Expedition began two years ago when reports came of a cave that appeared to have human remains. From there, Lee Berger assembled a team to explore this cave and see just how much was down there.
Turns out...a LOT was down there. So far, over 1500 fossils have been collected, from about 15 individuals--several of which seem to have associated skulls/skeletons.
That...is MIND-BOGGLING. For perspective, less than 5 finds in the history of early human paleoanthropology have consisted of an individual with skull and skeleton bones together. And here, in this one cave, are so, so, SO many more. Adults, infants, elderly...all here.
The species was given the name Homo naledi, after the cave in which they were discovered. I was lucky enough to see models of them in person in October. The hands and feet of these early humans are astonishing--so similar to ours, even though they themselves were only the size of Lucy. Their hands could certainly manipulate tools, but their brains were close to that of a chimpanzee's. Additionally, the way the fossils are deposited suggests deliberate, perhaps ritualistic, disposal of the dead by other members of the species. WHAT?! Wow. We have a lot to learn about this new species, and it is going to greatly influence our understanding of human evolution.
The biggest question remaining is the age of the specimens. There is no easy way to deduce it, because of the nature of the find, but I have faith science will find a way. This is too big of a find not to put our best efforts towards.
There are still a ton more fossils down in the cave, but to access it, you have to be an incredibly brave spelunker--and incredibly small! One passage is only 8 inches wide. I can't wait to see what more comes from this find in the future, and am still just completely blown away by what's been found so far.
So there you have it. My top science stories of the year. Onwards, to 2016!