On 9 November 2011, UVOT photographed the asteroid 2005 YU55 as the asteroid made a close flyby of the Earth. On 3 June 2013, UVOT unveiled a massive ultraviolet survey of the nearby Magellanic Clouds. In August 2017, UVOT imaged UV emissions from gravitational wave event GW170817 detected by LIGO & Virgo detectors. Experiments Burst Alert Telescope (BAT) BAT (Burst Alert Telesope) is a gamma ray telescope, built by NASA's Goddard Space Flight Center, uses a coded aperture to locate the source. The software to locate the source is provided by the Los Alamos National Laboratory (LANL). The CdZnTe detector of area, consisting of 32,500 units of , can pin-point the location of sources within 1.4 arcminutes. The energy range is 15-150 keV. Ultraviolet/Optical Telescope (UVOT) UVOT (Ultraviolet/Optical Telescope) monitors the afterglow in ultraviolet and visible light, and locates the source at an accuracy of one arcsecond. Its aperture is , with an f-number equal to 12.7, and is backed by 2048 x 2048 photon counting CCD pixels. The source location accuracy is better than one arcsecond. X-Ray Telescope (XRT) XRT (X-Ray Telescope) aims at the source more accurately, and monitors the afterglow in X-rays. It was built jointly by the Pennsylvania State University (PSU), the Brera Astronomical Observatory, Italy, and the University of Leicester, United Kingdom. It has a detector of area consisting of 600 x 600 pixels, and covers the energy range of 0.2-10 keV. It can locate the afterglow source at an accuracy of four arcseconds. Mission goals The Swift mission has four key scientific objectives: To determine the origin of GRBs. There seem to be at least two types of GRBs, only one of which can be explained with a hypernova, creating a gamma-ray beam. More data is needed to explore other explanations To use GRBs to expand understanding of the young universe. GRBs seem to take place at "cosmological distances" of many millions or billions of light-years, which means they can be used to probe the distant, and therefore young, cosmos To conduct an all-sky survey which will be more sensitive than any previous one, and will add significantly to scientific knowledge of astronomical X-ray sources. Thus, it could also yield unexpected results To serve as a general purpose gamma-ray/X-ray/optical observatory platform, performing rapid "target of opportunity" observations of many transient astrophysical phenomena, such as supernova Mission history Swift was launched on 20 November 2004,