1.   Heating these storage systems or decreasing their internal pressure causes the hydrogen to be released, they said.

2.   In a series of lab experiments, microbiologist Todd Stevens of Pacific Northwest National Laboratory showed that basalt may react with groundwater to release hydrogen.

3.   Space officials said they found some residue on the outside of the vent, which releases waste hydrogen into space.

4.   They found some residue on the outside of the vent, which releases waste hydrogen into space.