The best ever images of Neptune were taken by NASA's Voyager 2 spacecraft back in 1989. Now, new images captured by The European Southern Observatory's Very Large Telescope in Chile offer a fresh view of the planet.
Laser Tomography
ESO's ground-based telescope had an upgrade that now allows it to rival the imaging capability of NASA's Hubble Space Telescope. To test the VLT's new capabilities, scientists turned the telescope's eyes to Neptune, which is located about 4.7 billion kilometers from Earth, and some star clusters and objects in the sky.
Scientists used the a new adaptive optics mode known as laser tomography in their observations and were able to capture remarkable images of Neptune and stellar clusters.
Distorted Appearance Of Objects In Space
The Earth's atmosphere can distort the appearance of objects in space, blurring distant objects and causing stars to twinkle. To make observations from the ground, the blur needs to be corrected, and a reference point can help determine how much correction is needed.
VLT's new adaptive optics use lasers projected into the sky to correct this turbulence in the atmosphere.
Scientists installed the mirror of VLT's Unit Telescope 4 with four powerful lasers that shoots intense beam of light in the sky and excites the sodium atoms in the upper layer of the atmosphere.
These atoms serve as laser guide stars, and the light they bounce back is used to measure atmospheric turbulence. A secondary mirror corrects the atmospheric distortion as turbulence is measured in real time.
Sharper And More Detailed Images
The new method results in sharper and more detailed images. With VLT's new capabilities, it is now possible to capture space images from the ground at visible wavelengths that are sharper than those from Hubble.
"The MUSE Wide Field Mode coupled to GALACSI in ground-layer mode corrects for the effects of atmospheric turbulence up to one kilometre above the telescope over a comparatively wide field of view," ESO said.
"The new Narrow Field Mode using laser tomography corrects for almost all of the atmospheric turbulence above the telescope to create much sharper images, but over a smaller region of the sky."
ESO said that the ability to take sharp images will allow astronomers to study the properties of astronomical objects in much greater detail than before. Sharper images of objects in space can allow scientists to determine what stars, nebulae, and planets are made of and how they formed.
