Hubble/JPL/NASA/ESA

Scientists hope this Hubble Space Telescope Image, released earlier this month, will help them predict the fate of our Sun by unraveling the mysteries of Sun-like stars that are older and dying.

The photograph is of a protoplanetary nebula called IRAS22036+5306. These objects are thought to evolve into planetary nebula, beautiful billowing structures that signal the end of a star's life.

Though not as stunning as some Hubble images, this is one of the best ever made that capture's the fleeting pre-nebula stage, astronomers said. The star has bloated to dozens of times its original size and is called a red giant. The outer layers are lit up by ultraviolet light still shining from the dying core.

Our Sun, too, will become a red giant in a few billion years. Earth will likely be fried in the process, and one scientist recently speculated that distant Pluto could become an oasis for life. But scientists don't fully understand what red giants do, particularly as they go through the brief protoplanetary nebula phase.

"Protoplanetary nebulas are rare objects with short lifetimes," said astrophysicist Raghvendra Sahai of NASA's Jet Propulsion Laboratory. "It has generally been very difficult to obtain images of such objects in which their structure can be resolved in detail."

This image contains a series of what Sahai and his colleagues call "knotty jets" that emerge along roughly straight lines from the center of the cigar-shaped, bipolar nebula (click the image to enlarge it, then see the black-and-white inset).

Astronomer have not pinned down what causes the ephemeral jets. [Nebula Image Gallery]

-- Robert Roy Britt