Universe Today
This consists of four lasers that are fixed to the fourth Unit Telescope (UT4) beaming intense orange light into the sky, simulating sodium atoms high in the atmosphere and creating artificial "Laser Guide Stars". Light from these artificial stars is then used to determine the turbulence in the atmosphere and calculate corrections, which are then sent to the deformable secondary mirror of the UT4 to correct for the distorted light.
Using this Narrow Field Mode, the VLT was able to capture remarkably sharp test images of the planet Neptune, distant star clusters (such as the globular star cluster NGC 6388), and other objects. In so doing, the VLT demonstrated that its UT4 mirror is able to reach the theoretical limit of image sharpness and is no longer limited by the effects of atmospheric distortion.
This essentially means that it is now possible for the VLT to capture images from the ground that are sharper than those taken by the Hubble Space Telescope. The results from UT4 will also help engineers to make similar adaptations to the ESO's Extremely Large Telescope (ELT), which will also rely on laser tomography to conduct its surveys and accomplish its scientific goals.
These goals include the study of supermassive black holes (SMBHs) at the centers of distant galaxies, jets from young stars, globular clusters, supernovae, the planets and moons of the Solar System, and extra-solar planets. In short, the use of adaptive optics - as tested and confirmed by the VLT's MUSE - will allow astronomers to use ground-based telescopes to study the properties of astronomical objects in much greater detail than ever before.
In addition, other adaptive optics systems will benefit from work with the Adaptive Optics Facility (AOF) in the coming years. These include the ESO's GRAAL, a ground layer adaptive optics module that is already being used by the Hawk-I infrared wide-field imager. In a few years, the powerful Enhanced Resolution Imager and Spectrograph (ERIS) instrument will also be added to the VLT.