Astronomers spot ‘cosmic caterpillar’ 6 trillion miles long

protostar caterpillar

Photo credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and the IPHAS Survey

A light-year equals about 6 trillion miles--the sun is about 93 million miles from Earth, for perspective--so what NASA's Hubble Space Telescope discovered 4,500 light-years away in the Cygnus constellation is nothing short of incredible.

The Hubble Heritage Project on Thursday released a photo of what it calls a cosmic caterpillar that stretches 6 trillion miles long. It's actually a protostar, a mass of gas and dust that eventually produces a star. This one, called IRAS 20324+4057, is in the very early evolutionary stage. It has also been described as a "tadpole in an interstellar pond."

Watch this video zoom in to the cosmic caterpillar within the Cygnus constellation:

More from The Hubble Heritage Project:

This light-year-long knot of interstellar gas and dust resembles a caterpillar on its way to a feast. But the meat of the story is not only what this cosmic caterpillar eats for lunch, but also what’s eating it. Harsh winds from extremely bright stars are blasting ultraviolet radiation at this “wanna-be” star and sculpting the gas and dust into its long shape. [...]


The caterpillar-shaped knot, called IRAS 20324+4057, is a protostar in a very early evolutionary stage. It is still in the process of collecting material from an envelope of gas surrounding it. However, that envelope is being eroded by the radiation from Cygnus OB2. Protostars in this region should eventually become young stars with final masses about one to ten times that of our Sun, but if the eroding radiation from the nearby bright stars destroys the gas envelope before the protostars finish collecting mass, their final masses may be reduced.

Who knows what happens to the wannabe-star?

“Only time will tell if the formed star will be a ‘heavy-weight’ or ‘light-weight’ with respect to its mass,” the project concludes.