When researchers drilled a hole into California’s San Andreas fault, they dropped a string of instruments down into its depths in 2008 that they hoped would take readings of seismic and magnetic activity for years. But that experiment, called the San Andreas Fault Observatory at Depth, failed just days into its run. Last year, when researchers pulled the instruments back up for examination, they brought with them a batch of stinking mud and some bad news. Analysis of the string suggested that these sorts of instruments just aren’t up to surviving in the hot, acidic conditions down the hole, says National Science Foundation (NSF) EarthScope programme director Greg Anderson — at least not with the technologies available at present. “It will take years before we might try again,” he said at the American Geophysical Union meeting in San Francisco this week.

The good news is, this means that the hole is now free for use by anyone who wants to put in a proposal to use it — and not just for disposing of lazy grad students or rejected papers. Shorter-term projects or more ‘passive’ instruments would probably survive the conditions, says Anderson. Principal investigators keen on trying their luck need simply submit plans to the NSF. “We’re open to proposals,” he says.