LISA Pathfinder - First steps to observing gravitational waves from space

The concept of gravitational-wave detection is based on monitoring two freely falling bodies. As long as all other disturbances can be sufficiently reduced and the two bodies are truly moving under the effect of gravity only, a gravitational wave passing between them would change their separation. LISA Pathfinder will test the underlying and most challenging condition for such experiments: whether it is possible to put two test masses into a near-perfect gravitational free-fall.

Mind the Binaries

Mergers of binary black holes from dense star clusters may be promising sources of gravitational waves.

Black holes merging seen edge-on. Source: black-holes.org

Inside LISA Pathfinder

ESA’s LISA Pathfinder mission is a technology demonstrator that will pave the way for future spaceborne gravitational-wave observatories. It will operate about 1.5 million km from Earth towards the Sun, orbiting the first Sun–Earth ‘Lagrangian point’, L1.

Source: ESA

Simulating a proto-neutron star

Each century, about two massive stars in our own galaxy explode, producing magnificent supernovae. These stellar explosions send fundamental, uncharged particles called neutrinos streaming our way and generate ripples called gravitational waves in the fabric of space-time. Scientists are waiting for the neutrinos and gravitational waves from about 1,000 supernovae that have already exploded at distant locations in the Milky Way to reach us. Here on Earth, large, sensitive neutrino and gravitational-wave detectors have the ability to detect these respective signals, which will provide information about what happens in the core of collapsing massive stars just before they explode.