X

'Bent light' offers glimpse of huge galaxy 11.7 billion light years away

Astronomers have used a trick of general relativity to look around a corner, of sorts, and view a massive, distant galaxy with remarkable clarity.

Eric Mack Contributing Editor
Eric Mack has been a CNET contributor since 2011. Eric and his family live 100% energy and water independent on his off-grid compound in the New Mexico desert. Eric uses his passion for writing about energy, renewables, science and climate to bring educational content to life on topics around the solar panel and deregulated energy industries. Eric helps consumers by demystifying solar, battery, renewable energy, energy choice concepts, and also reviews solar installers. Previously, Eric covered space, science, climate change and all things futuristic. His encrypted email for tips is ericcmack@protonmail.com.
Expertise Solar, solar storage, space, science, climate change, deregulated energy, DIY solar panels, DIY off-grid life projects. CNET's "Living off the Grid" series. https://www.cnet.com/feature/home/energy-and-utilities/living-off-the-grid/ Credentials
  • Finalist for the Nesta Tipping Point prize and a degree in broadcast journalism from the University of Missouri-Columbia.
Eric Mack
2 min read

93152web.jpg
An "Einstein Ring" seen from a wider view (left), mid-range and close-up (right) ALMA (NRAO/ESO/NAOJ) / Y. Tamura (University of Tokyo) / Mark Swinbank (Durham University)

The deeper we look into space and time, the crazier the concepts tend to get.

The images above, released Monday by the European Southern Observatory, show an absolutely massive galaxy some 11.7 billion light years away -- thanks to the light it emits being literally bent through an effect called " gravitational lensing." This effect makes the galaxy observable from Earth in the form of something called an " Einstein Ring" when everything is aligned just right.

To break that down a bit, famed physicist Albert Einstein came up with the theory of general relativity that's responsible for much of what we think we know today about how the universe works at very large scales, which is typically what we're dealing with in space. It tells us that massive objects, like galaxies, can actually bend space and time and that everything traveling through the resulting curved space also travels along the same curved path.

In the case of this very distant galaxy, the one 11.7 billion light years away named SDP.81, it is actually located behind a closer galaxy called SDSS J0903 (a "mere" 3.4 billion light years away), which you might presume would make that more distant galaxy impossible to see on account of pesky SDSS J0903 blocking the view both physically and with its own emitted light.

But it turns out Einstein was on to something and that the closer galaxy bends the space and time around it, allowing the light from the more distant galaxy to curve around the blocking galaxy and show itself in the form of an Einstein Ring appearing around the closer galaxy.

Told you this stuff was crazy.

While it's hard to say exactly how massive the distant galaxy is, it has (or rather, had, since the observed light is more than twice as old as Earth itself) dust clouds that measure up to 500 light years across, making up star-forming elliptical regions of the galaxy 5,000 light years across.

This is the kind of information that's normally pretty hard to discern about such a distant galaxy without the help of the natural telescope of sorts created by gravitational lensing.

The images of this particular Einstein Ring come from data captured via the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which also be featured in no less than eight papers to be published in scientific journals in the "near future," according to the European Southern Observatory. You can access all those papers here.