Electromagnetic pulses and violent space weather outbursts might seem like national security threats straight out of science fiction. But the House Homeland Security Committee wants to ensure federal agencies are doing their best to prepare for them.

During an Oversight and Management Efficiency subcommittee hearing Tuesday, legislators reviewed the possible ramifications that a man-made EMP weapon, detonated nuclear device or even space weather phenomena could have on the nation’s power grid. While seemingly remote, the threats drew comparisons to the Japanese attack on Pearl Harbor in 1941 and the Sept. 11 terrorist attacks.

While unlikely, being unprepared could mean loss of life and could be devastating to the nation’s telecommunications and power grid, lawmakers said. One report estimates the potential cost of a large-scale solar storm, emanating from a large release of energy by the sun, could exceed $2 trillion and leave large portions of the population without power for months or longer.