For this week, NASA's Hubble image is exhibiting a sparkling of galaxies coming in various sizes and shapes. A domineering appearance in the image is the ACO S 295 galaxy cluster, positioned at a 3.5- billion-light-year distance in the Horologium's constellation.

Horologium constellation, according to The Nine Planets site, is also known as the "celestial pendulum clock," a faint constellation that's seen in the southern celestial hemisphere. It was Nicolas Louis Lacaille, a French Astronomer, who first described it in 1756.

The clusters of galaxies are nearly unfathomably large and, in fact, are the universe's largest objects which gravity holds together.

Typically, they comprise between100 and 1,000 galaxies. More so, their mass can be as huge as a quadrillion suns.

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Gravitational Lensing

A Digital Trends report said, there is a matter to be discovered in space as well, between galaxies, which, it turns out, not totally empty. In addition, there is interstellar gas present, that forms a plasma also known as intracluster medium.

Since galaxy clusters are so quite huge, their gravity is impacting light that's passing near them. If one looks quite carefully, he can see that the background galaxies in the image have extended and smeared shapes.

This occurs because of a phenomenon known as gravitational lensing. According to NASA's HUBBLESITE, gravitational lensing takes place, when taken to the extreme, gravity can produce some interesting visual impacts that Hubble's well-suited for observation.

The general theory of Albert Einstein of relativity is describing how mass concentrations are distorting the space surrounding them.

Essentially, a gravitational lens can take place when a large amount of matter, such as a cluster of galaxies, produces a gravitational field, distorting and magnifying the light from distant galaxies behind it, although in a similar line of sight.

The impact, this report specified, is like looking through a gigantic magnifying glass. It enables scientists to study the early galaxies' details too far away to be observed with the present telescopes and technology.

Occurring Not Just in Galaxy Clusters

Essentially, gravitational lensing does not only take place with large clusters of galaxies. It takes place too, on a smaller scale like when the light coming from a single star is passing near another star.

The acts, the same as a magnifying glass, enabling researchers to see more details of the background star. This particular technique can even be utilized to look for exoplanets, similarly as it will be used in the forthcoming Nancy Grace Roman Space Telescope.

Designed by NASA observatory, the Roman Space Telescope will answer important questions in the areas of exoplanets, infrared astrophysics, and dark energy.

NASA describes the telescope as having a main mirror that's 7.9 feet in diameter, with a similar site as the primary mirror of the Hubble Space Telescope.

This space telescope will comprise a pair of instruments: The Wide Field Instrument and the Coronagraph Instrument.

The former, as the main instrument will measure light from a billion galaxies over the period of the mission lifetime. The Roman Space Telescope will have a main mission lifetime of five years, with a possible five-year extension for the mission.

Related information about gravitational lensing is shown on BBC Earth Lab's YouTube video below: 

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Check out more news and information on the Hubble Space Telescope in Science Times.