xiox writes: The European Space Agency (ESA) have decided that its next two large astronomy missions (costing 2bn Euros) will be to study two aspects of the "invisible universe". The first will be a very large X-ray telescope to be launched in 2028. It will study the physics of the hottest and largest structures in the universe, investigating how they formed and evolved. It will also investigate how black holes grow and affect the universe. The second mission, launched in 2034, will be an observatory capable to measure gravitation waves, the stretches and compressions in space-time caused by massive moving systems, such as merging pairs of black holes. Although the final designs are not yet chosen, the two proposed observatories Athena and eLISA are likely choices. BBC News has more information.