Scientists also learned more about our human ancestors this year. It turns out that early humans didn't hesitate to get freaky with other species, and interbred with hominins like Denisovans and Neanderthals.
A genetic study published in March revealed that as early Homo sapiens made their way out of Africa, they had sex and interbred with Denisovans on numerous occasions.
For only the third time, a woman won the Nobel Prize in physics.
Donna Strickland, an associate professor of physics at the University of Waterloo, in Canada, shared the 2018 Nobel Prize in physics with a French scientist for her work on lasers.
The Nobel in physics has been awarded to 210 people. Strickland, whose Wikipedia entry had previously been rejected because she wasn't famous enough, was surprised to learn that out of all those winners, she was only the third woman.
"Is that all, really? I thought there might have been more," she said. "We need to celebrate women physicists, because we're out there."
This year, a female chemist won the Nobel Prize too. Frances Arnold became the fifth woman since 1901 to get it. The award recognized her work in using directed evolution to produce enzymes for new chemicals and pharmaceuticals.
"All this tremendous beauty and complexity of the biological world all comes about through this one simple, beautiful design algorithm," Arnold said after she won half of the 2018 prize. "What I do is use that algorithm to build new biological things."
The Nobel Prize in chemistry has been awarded to 181 people since 1901.
Scientists discovered two new kinds of giant dinosaurs.
A study about one new species, discovered in Argentina, was published in July. The creature is called Ingentia prima, a name derived from the Latin words for "huge" and "first." The dinosaur weighed as much as three African elephants when it roamed 210 million years ago (that's 30 million years earlier than scientists previously thought giant dinosaurs existed).
Another dinosaur, called Ledumahadi mafube, was discovered in South Africa, according to research published in September. It's believed to have lived 200 million years ago. That means both creatures would've been around at the time of Pangea, when the world's land was still one supercontinent.
"It shows how easily dinosaurs could have walked from Johannesburg to Buenos Aires at that time," Wits University paleoscientist Jonah Choiniere said.
Climate scientists learned more about how our warming planet is hurting us.
Scientists estimatedHurricane Florence, which hit the US in September, was more than 50% wetter than the storm would have been without climate change.
The heat-trapping gas that's been added to Earth's atmosphere through the burning of fossil fuels also means that a trillion dollars in coastal real estate could be threatened by the end of this century. That's according to a recent report released by the Trump administration, which also found that thousands more people will die each year from heat-related conditions if we keep up business as usual.
Investigators cracked the Golden State Killer case using DNA matching. The implications of that strategy are huge.
The suspected Golden State Killer, who'd been at large for more than three decades, was finally caught in April because a distant relative's DNA was available on a public genealogy website.
A study released in October estimates that 60% of white Americans — the biggest consumers of DNA testing services — could now be identified up to a "third cousin or closer" using available DNA data.
This was a banner year for scientists in US politics: Americans elected at least 10 new science pros to Congress.
Nearly all of those successful scientist candidates were Democrats who unseated Republican incumbents in the 2018 midterm elections.