(Left to right): JPL-Caltech/NASA; BSIP SA/Alamy Stock Photo; CHICAGO BRIDGE & IRON

Top stories: Jupiter’s stormy skies, why whales got so big, and the great petunia carnage of 2017

How the transgenic petunia carnage of 2017 began

Regulators in Europe and the United States are asking flower breeders to destroy vast numbers of petunias after a chance discovery by a Finnish plant biologist revealed that several varieties are genetically engineered. Officials say the petunias pose no threat to human health or the environment—and likely were unknowingly sold for years—but it’s illegal to sell them without a permit. The petunia carnage highlights the growing complexity of regulating genetically engineered plants, which have a history of showing up where they aren’t allowed.

Jupiter’s skies are peppered with electron streams, ammonia plumes, and massive storms

Scientists have long known that Jupiter is a stormy place. But since NASA’s Juno probe reached the solar system’s largest planet last July, they’ve found it to be a far more tempestuous planet than they realized. The first-ever detailed look at Jupiter’s polar regions reveals chaotic swirls of storms, some measuring up to 1400 kilometers across. The study also shows that Jupiter’s equator is home to a broad plume of ammonia rising from deep layers of the atmosphere, a “striking and unexpected” feature found by beaming microwaves into the jovian atmosphere.

Chemists may be zeroing in on chemical reactions that sparked the first life

Many researchers believe that life on Earth got started with DNA’s cousin, RNA. But those favoring an “RNA world” hypothesis have struggled for decades to explain how the molecule’s four building blocks could have arisen from the simpler compounds present during our planet’s early days. Now, chemists have identified simple reactions that, using the raw materials on early Earth, can synthesize close cousins of all four building blocks, suggesting that scientists may be closing in on a plausible scenario for how life on Earth began.

Star that spurred alien megastructure theories dims again

Astronomers and alien life enthusiasts alike are buzzing over the sudden dimming of an otherwise unremarkable star 1300 light-years away in the constellation Cygnus. KIC 8462852, or “Tabby’s star,” has dimmed like this several times before, prompting some researchers to suggest that the megastructures of an advanced alien civilization might be blocking its light. And now—based on new data from numerous telescopes—it’s doing it again.

Why whales grew to such monster sizes

Weighing in at 200,000 kilograms and stretching the length of a basketball court, the blue whale is the biggest animal that’s ever lived. Biologists have long debated why some whales became so huge. Some have proposed that because water bears the animal’s weight, whales can move around more easily and gulp in enough food to sustain big appetites. Others have suggested that whales got big to fend off giant sharks and other megapredators. Now, scientists have figured out the real reason.

Goodbye, smokestacks: Startup invents zero-emission fossil fuel power

Between the energy hub of Houston, Texas, and the Gulf Coast lies a sprawling petropolis: a sea of refineries and oil storage tanks, power lines, and smokestacks, all dedicated to converting fossil fuels into dollars. But here, on the eastern edge of that carbon dioxide hot spot, a new fossil fuel power plant showcases a potential remedy for Houston's outsized greenhouse gas footprint. The facility looks suspiciously like its forebears, a complex the size of two U.S. football fields, chockablock with snaking pipes and pumps. It has a turbine and a combustor. But there is one thing it doesn't need: smokestacks.