The (fictional) aliens spoke, and President Donald Trump apparently listened.
The president's 2018 federal budget blueprint, which was released today (March 16), would end work on a proposed NASA mission to put a life-hunting lander down on the surface of Jupiter's ocean-harboring moon Europa.
"To preserve the balance of NASA’s science portfolio and maintain flexibility to conduct missions that were determined to be more important by the science community, the Budget provides no funding for a multibillion-dollar mission to land on Europa," the blueprint reads. [Europa May Harbor Simple Life-Forms (Video)]
This directive is in keeping with the one issued by advanced aliens in famed sci-fi author Arthur C. Clarke's 1982 book "2010: Odyssey Two."
"All these worlds are yours — except Europa," the aliens say in a message sent to Earth. "Attempt no landing there."
The blueprint does fund continued development of NASA's $2 billion Europa Clipper mission, which will launch in the 2020s and investigate the habitability of the Jovian moon — widely regarded as one of the solar system's best bets to host alien life — during dozens of flybys. (The lander concept was an add-on requested by Congress in late 2015; the space agency has been working since then to determine the best way to make a surface mission happen.)
The budget blueprint also cancels NASA's Asteroid Redirect Mission, an effort to pluck a boulder off a space rock and tow the piece to lunar orbit, where it would be visited by astronauts. And the proposal axes four NASA Earth-science projects: The Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite, which would monitor Earth's oceans and atmosphere; the Orbiting Carbon Observatory-3 (OCO-3), which would track atmospheric carbon-dioxide levels from the International Space Station (ISS); the Climate Absolute Radiance and Refractivity Observatory (CLARREO) pathfinder, another instrument that would be installed on the ISS; and, finally, the Deep Space Climate Observatory (DSCOVR).
PACE, OCO-3 and CLARREO are all scheduled to launch in the next few years. But DSCOVR, a joint mission of NASA and the National Oceanic and Atmospheric Administration, lifted off in February 2015 and is currently studying the Earth and space weather.
NASA receives $19.1 billion in the proposed budget, a 0.8-percent cut from 2017 funding levels, according to the federal Office of Management and Budget.
The newly released blueprint is just a proposal, and a rather skeletal one at that. (Trump administration officials said they will unveil a more fleshed-out version in May.) It's unclear at the moment which parts of the proposal will survive the inevitable back-and-forth with Congress and actually become law.
You can read the Trump administration's 2018 budget blueprint here.
Editor's Note: This story was corrected to state that the Europa message was in Arthur C. Clarke's novel "2010: Odyssey Two," not "2061: Odyssey Three."
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Michael Wall is a Senior Space Writer with Space.com and joined the team in 2010. He primarily covers exoplanets, spaceflight and military space, but has been known to dabble in the space art beat. His book about the search for alien life, "Out There," was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Michael on Twitter.