Hubble Space Telescope deep-sky survey reveals embryonic galaxies

This is a selection of images of unusual galaxies discovered during a serendipitous sky survey with the Wide Field Camera onboard NASA/ESA Hubble Space Telescope (Ht1). This is a colour composite of two images taken at different wavelengths: visible light (yellow) and near infrared (red).

The individual galaxies are estimated to be between three and ten billion light-years away. HST's high resolution reveals that they have unusual irregular shapes which are not like the familiar spiral and elliptical galaxies in the nearby universe. One idea is that the fragmentary galaxies are interacting, as evident in some of the images which show apparent mergers. The objects resolved by HST may be the "building blocks" for today's large galaxies.