The Hubble Space Telescope has discovered a "string of pearls" that is wrapped around two colliding elliptical galaxies.

The string has a length of around 100,000 light years and has blue-colored "pearls," which are in fact massive clusters of young stars, appearing at 3,000 light year intervals along its length.

Grant Tremblay, from the European Southern Observatory in Germany, expressed his surprise upon the discovery.

"We've long known that the 'beads on a string' phenomenon is seen in the arms of spiral galaxies and in tidal bridges between interacting galaxies. However, this particular supercluster arrangement has never been seen before in giant merging elliptical galaxies," said Tremblay in a statement released by NASA.

The pair of colliding galaxies are located within the J1531+3414 cluster, with both having widths of around 330,000 light years. Compare that to the width of the Milky Way galaxy, which is only about 100,000 light years.

The collision of the galaxies led to the formation of young, blue star clusters. Their structure similar to a string of pearls can be explained by the same principle that causes rain to land on earth as raindrops, and not as long, continuous streams from the sky.

The star formation is fueled by cold gas, the origin of which remains unclear. The gas may have been part of the two colliding galaxies since the beginning, or could have been the product of condensation from the bubble of extremely hot plasma that is surrounding the galaxies, decreasing in temperature due to the released shock wave of the collision of the two galaxies.

"Whatever the origin for this star-forming gas is, the result is awesome," said Tremblay.

The Hubble Space Telescope is a joint project between NASA and the European Space Agency. The telescope is managed by NASA's Goddard Space Flight Center, located in Greenbelt, Maryland, and Hubble science operations are carried out by the Space Telescope Science Institute in Baltimore, Ohio. The Association of Universities for Research in Astronomy operates STScI for NASA.

Earlier this month, the Hubble Space Telescope discovered two previously unknown celestial bodies beyond Pluto's orbit. The unknown bodies will be targeted to be visited by the New Horizons Spacecraft, which was launched in 2006 and will be the first spacecraft to reach Pluto when it flies by the planet by July of next year.

New Horizons previously did not have any other target to visit aside from what was once considered the most distant planet in our solar system.