WASHINGTON, Feb. 28 (UPI) -- NASA officials say the Hubble Space Telescope has taken the largest, most detailed photo of the spiral galaxy ever taken by the telescope.
The final image measures 16,000x12,000 pixels and is composed of 51 individual Hubble exposures, in addition to elements from images from ground-based photographs.
The Hubble observations that went into assembling the image were originally acquired for a range of Hubble projects: determining the expansion rate of the universe, studying the formation of star clusters in the giant star birth regions, finding the stars responsible for intense X-ray emission, and discovering blue supergiant stars.
The giant spiral disk of stars, dust and gas is 170,000 light-years across or nearly twice the diameter of our galaxy. The spiral galaxy -- M101 -- is estimated to contain at least 1 trillion stars, astronomers said, adding approximately 100 billion of those stars could be like our sun in terms of temperature and lifetime.
M101 -- also nicknamed the Pinwheel Galaxy -- lies in the northern circumpolar constellation Ursa Major at a distance of 25 million light-years from Earth.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency.