The Onion so incredibly funny. "Queen To Run Marathon", "Harvesting The Spaghetti Trees of Italy", "No Taxes in 2012". Told with a straight face they can just make us pause for an instant. That is interesting, these jokes are an opportunity to examine just what is ludicrous versus what might actually be a plausible extrapolation.
So, life in the universe, exoplanets, all fair game for April 1st. What would be clearly a hoax headline and what would be on the borders of acceptability?
"Star system found to harbor 18 planets, including 3 in habitable zone."
"Cassini Mission Spots Cruise Liner on Titan"
"Alien Microbes Found In Cheese: apparently taste 'really nice' "
"Journal of Discombobulation Publishes Theory: scientists baffled but impressed"
"Bacterium That Plays Music"
"Exoplanet Covered in Checkerboard"
"Life in Hydrothermal Vent Carries Gambling Gene"
"New Telescope to Search For Signs of Ruminants"
"Government Files Reveal Canals on Mars Were Real"
"New Horizons Probe Cannot Find Pluto"
"NASA to send astronauts to Neptune"
"Ancient Plants Used Sound to Communicate: fossil records tell story"
"Parallel Universe Detected in Parallel Universe"
"Kepler Mission Discovers Planets Made of Steel"
"Helium Loving Microbes Discovered"
"Europa Cracks Open: it's full of shrimp"
"SETI Hears Alpha Centauri Customer Service Menu"
and the last, best one:
"Over 1,500 Planets Discovered Since 1995: other Earths surely out there"