Hubble captures an impressive ‘mirror galaxy’ image 6.9 billion lightyears from Earth

The Hubble Space Telescope captured an impressive “mirror image” of a galaxy thanks to the phenomenon of gravitational lensing, a press statement from the European Space Agency reveals.

The capture, shown above, appears to be of two galaxies connected to each other. In reality, it’s just one, named SGAS J143845+145407.

We are viewing the magnified galaxy’s light reaching us from two different sides of a distant galaxy cluster.

Hubble captures a distant ‘mirror galaxy’

Gravitational lensing allows astronomers to peer much further into the distant galaxy. This is thanks to a quirk of gravity that distorts the light passing through the gravitational field of a massive object, such as a galaxy cluster. The object that is distorted by gravity is referred to as “lensed.”

Crucially, this lensed object is also magnified during the process, meaning gravitational lensing allows scientists to see incredibly distant objects with greater clarity. The illustration below shows how light can be warped as it travels the thousands, millions, or billions of lightyears it takes to reach Earth.

Hubble captures an impressive 'mirror galaxy' image 6.9 billion lightyears from Earth
The illustration above shows the phenomenon of gravitational lensing in action. Source: NASA, ESA & L. Calçada

In Hubble’s new gravitational lensing image, the galaxy SGAS J143845+145407 is positioned at the exact location behind a small galaxy cluster for the cluster to create a distorted “mirror image” of the galaxy. The light from SGAS J143845+145407 traveled approximately 6.9 billion years to reach Earth. The cluster, meanwhile, is about 2.8 billion years from Earth.

The Hubble Space Telescope revolutionized gravitational lensing

The first scientific image revealed from the James Webb Space Telescope features distorted objects that are a result of gravitational distortion and lensing.

SGAS J143845+145407 is a luminous infrared galaxy with high star formation activity, meaning it may also be a target for James Webb in the not-too-distant future. That’s not to say Hubble’s new observations of the galaxy aren’t extremely valuable. Using Hubble’s gravitational lens images, scientists were able to reconstruct the distribution of star formation in SGAS J143845+145407, and investigate the spiral galaxy in new detail.

The new images serve as a reminder of Hubble’s great power and the incredible role it has played in astronomy over the more than 30 years since its launch. James Webb may now be at the center of the astronomical community’s attention, but Hubble revolutionized the method of gravitational lensing and set much of the groundwork for James Webb’s technology and observations today.

Both space observatories will continue to capture images of the cosmos, allowing us to peer further into the distant galaxy, and into the past, than ever before.

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