Webb Telescope: The Early Universe Was Like Bananas

Galaxies in their infancy captured by the James Webb Space Telescope look strange. Their elongated appearance suggests a three-dimensional structure similar to that of a banana, according to new research.

For a long time, many astrophysicists assumed that newborn galaxies would look like the balls and spider-like disks familiar from the modern Universe.

But according to an analysis of new images from the James Webb Space Telescope, the newborn galaxies were shaped like bananas. This is the preliminary conclusion reached by a team of astronomers who re-examined images of about 4 thousand newborn galaxies observed by Webb.

“This is both a surprising and unexpected result, although the Hubble telescope already had hints of this,” said Viraj Pandya, a research fellow at Columbia University.

The results may also provide insight into the mysterious nature of dark matter, an unknown and invisible form of matter that astronomers say makes up the majority of the universe and outweighs atomic matter by a ratio of 5 to 1. This unknown something consumes galaxies and provides the gravitational breeding grounds in which new systems.

The finding builds on earlier Hubble observations that the earliest galaxies were shaped like pickles, said University of California astronomer Joel Primack.

Scientist Alan Dressler remains somewhat skeptical about this result, given how difficult such measurements are to make, especially for galaxies that are far away, small and not very bright.

Scientists estimate that there are two trillion of them within the visible Universe, and each of them contains up to a trillion stars. But the visible universe is only a small part of what is out there. Most matter in space appears to be in the form of dark matter.

Recall that the Webb telescope was designed to study the emerging and mysterious epoch of the Big Bang. With a giant mirror and infrared sensors, it can see the most distant and therefore the earliest galaxies.

“They invariably appear very linear,” Pandya noted, “and some galaxies show numerous bright clusters arranged like pearls in a necklace.”

Such oblong galaxies are rare today, but they make up up to 80 percent of the galaxies in the CEERS sample, which dates back to about 500 million years after the Big Bang and was discovered by the telescope in July 2022.

“Their masses are such that they could be the progenitors of galaxies similar to the Milky Way,” Pandya explained, “implying that our own galaxy may have gone through a similar surfboard morphological phase in the past.”

In the modern Universe, galaxies appear to come in two basic shapes: featureless, round clouds called ellipticals, and flat, spider-like disks like our native Milky Way.

In early research, astrophysicist Jeremy Ostriker turned his attention to fuzzy dark matter. In 1973, he and his colleague James Peebles pointed to the important role of dark matter in stabilizing galaxies.

He and the team noted that fuzzy dark matter would leave its mark on the sizes and shapes of young galaxies, because it has no limit. However, modern telescopes are nowhere near sensitive enough to observe such “babies,” so it is clear to scientists that a new generation of even more powerful instruments may be needed to complete the work.

When Dr. Ostriker learned about Dr. Pandya’s work, he noticed that the prospects for fuzzy dark matter were looking better and better. “Keep up the good work,” he commented to The New York Times.