Tonight's Sky
Sun
Sun
Moon
Moon
Mercury
Mercury
Venus
Venus
Mars
Mars
Jupiter
Jupiter
Saturn
Saturn

Tonight's Sky — Change location

OR

Searching...

Tonight's Sky — Select location

Tonight's Sky — Enter coordinates

° '
° '

Snapshot: Strands of the cosmic web revealed

Astronomers have directly imaged for the first time the filaments of gas crisscrossing the universe. 
RELATED TOPICS: COSMOLOGY | GALAXIES
Glowing gas in the cosmic web
Glowing gas (blue) in the cosmic web is being lit up by billions of never-before-seen galaxies.
ESO/NASA/Roland Bacon et al.

A giant cosmic web of invisible gas weaves throughout the universe, providing the scaffolding out of which galaxies were born. Before now, however, the only way to see this web was indirectly, in a few select regions where a bright backlight happens to be situated behind the gas. These backlights are quasars — light from infalling matter around the supermassive black hole at a center of a galaxy. But such superpositions are rare and only provide a limited view of this vast, cosmos-spanning structure.

Now, astronomers eager to study this cosmic webbing have a new method that avoids the need for chance alignments. For 140 hours, they focused the European Southern Observatory’s Very Large Telescope on a section of the Hubble Ultra Deep Field — the deepest view of the universe ever captured. With the help of the Multi Unit Spectroscopic Explorer (MUSE), they were able to directly capture the light from the cool hydrogen gas of cosmic filaments just 1 to 2 billion years after the Big Bang. The filament they imaged extends over 15 million light-years, or some 150 Milky Ways placed side by side.

And its light hid a further surprise: It comes from the new stars in billions of dwarf galaxies never before seen in the early universe. Accounting for these numerous small galaxies will be an important test of the way astronomers believe galaxies form and grow over time.

0

JOIN THE DISCUSSION

Read and share your comments on this article
ADVERTISEMENT
FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. View our Privacy Policy.

ADVERTISEMENT
ADVERTISEMENT
Apollo_RightRail
A chronicle of the first steps on the Moon, and what it took to get there.