A self-portrait of NASA's Curiosity Mars rover. Photo: NASA/JPL-Caltech/MSSS via Getty Images

NASA scientists found evidence on Mars that suggests ancient life could have existed on the planet, providing "a piece of the Mars puzzle that scientists have long been seeking," per the New York Times. Specifically, scientists found organic matter in rock fragments that formed billions of years ago.

But, but, but: This isn't direct evidence of life itself, NASA cautions. Per the Times, the carbon molecules discovered by NASA's Curiosity rover can be found in meteorites, and can be produced "in chemical reactions that do not involve biology."

The details: After heating the rock fragments "to more than 900 degrees Fahrenheit," the NYT reports, Curiosity identified molecules that "wafted away" due to the high temperature. Scientists then examined which molecules were "genuine Martian organics." The molecules that remained were benzene and propane.

  • Scientists haven't pinned down how the molecules were formed, but are considering meteorites, biology and geology.
  • The argument for biology — that is, live material on the planet — isn't supported by "compelling evidence," the NYT reports, but NASA biogeochemist Jennifer L. Eigenbrode told the Times it's "on the table."

Another finding was that methane levels in Mars' atmosphere have gone "up and down by a factor of three...and appear to follow Martian seasons," per the Times.

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Exclusive: Inside McCarthy's new GOP messaging platform

House GOP Leader Kevin McCarthy (R-Calif.). Photo: Tasos Katopodis/Getty Images

House Republican Leader Kevin McCarthy (R-Calif.) has given his GOP colleagues new marching orders for stump speeches between now and November, as incumbents worry about how President Trump's own challenges may strain their re-election bids.

Driving the news: McCarthy delivered a PowerPoint presentation to the GOP conference in person last Thursday at the Capitol Visitor Center, with several members joining via Zoom, lawmakers and aides familiar with the gathering tell Axios.

Biden launches $280 million ad push

(Photo: Mark Makela/Getty Images)

Joe Biden's campaign is launching a $280m TV and digital ad campaign heading into the fall, targeting 15 states with a message — delivered directly from Biden — about the coronavirus pandemic and the economy.

Why it matters: The size of the buy, which advisers described on a call with reporters Tuesday night, signals a campaign that isn't worried about burning through cash — and it may force the Trump campaign, or associated super PACs, to increase their spending in response.

Updated 51 mins ago - World

China says U.S. is "endangering peace" with high-level visit to Taiwan

Health and Human Services Secretary Alex Azar during a June briefing in Washington, DC. Photo: Joshua Roberts/Getty Images

Health and Human Services Secretary Alex Azar announced Tuesday night he will lead a delegation to Taiwan "in the coming days."

Why it matters: It's the highest-level visit by a U.S. cabinet official to Taiwan since 1979. Azar is also the first U.S. Cabinet member to visit the island state in six years. The visit has angered China, which views Taiwan as part of its territory. Chinese officials accused the U.S. Wednesday of "endangering peace" with the visit, AFP reports.