ARI SHAPIRO, HOST:
A giant blob in outer space sounds like something from a classic sci-fi flick. In this case it's not fiction. Astronomers have spent years puzzling over cosmic objects that they actually call blobs. NPR's Nell Greenfieldboyce reports that scientists may have just uncovered the secret behind one blob's eerie glow.
NELL GREENFIELDBOYCE, BYLINE: Space blobs were first spotted back in the late 1990s. Chuck Steidel is an astronomer at Caltech. He and some colleagues were observing a bunch of galaxies in the distant reaches of the universe.
CHUCK STEIDEL: But we also saw these big, blotchy things.
GREENFIELDBOYCE: At first he thought they'd somehow screwed up the images - but no. They had accidently found strange glowing clouds of gas.
STEIDEL: And they were large - that is, 20 times the diameter of the Milky Way galaxy big.
GREENFIELDBOYCE: Steidel's team named these mysterious objects Lyman-alpha blobs - Lyman-alpha because that's the wavelength of ultraviolet light they emit and blobs because, well, the word blob is funny.
STEIDEL: Like the blob from outer space or something like that.
GREENFIELDBOYCE: He says the weird thing was, where was the light coming from? Why would a blob glow? Now an international team of astronomers has peered into one of the most famous blobs using a powerful telescope in Chile. Hiding inside, it found a pair of large galaxies. These galaxies are producing new stars at a frantic pace.
STEIDEL: Each galaxy is forming the equivalent of a hundred new suns every year.
GREENFIELDBOYCE: Jim Geach is an astronomer at the University of Hertfordshire in the United Kingdom. He says we couldn't see these galaxies before because they're so dusty. They were hidden even though all the commotion was lighting up their gaseous surroundings producing the blob.
JIM GEACH: Just like a streetlight on a foggy night, you see a sort of halo around the streetlight because the light from the central streetlight is scattering off water droplets in the fog. And it's kind of analogous to what we're seeing in these Lyman-alpha blobs.
GREENFIELDBOYCE: The findings appear in The Astrophysical Journal. Matthew Hayes is an astronomer at Stockholm University. He says now we know what's powering this particular blob, and he guesses if you look hard enough you'd find something like this in probably all of them.
MATTHEW HAYES: These things are still rare, and they're still kind of strange. But we're putting it together now I think.
GREENFIELDBOYCE: He says the mystery of the outer space blobs isn't completely solved, but they're getting there. Nell Greenfieldboyce, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.