Gravitational Lensing

Extended Description

Within a blue square are three smaller black squares shown at an angle. Two white lines ending in arrow points connect the black squares.

Below the top left black box, two labels appear. Next to an opaque red oval is text that reads "Observable distant galaxy." Beneath that and next to a red outline of an oval is text that reads "Distant galaxy too faint to detect." In the black box, which is the smallest of the three, there are nine red oval outlines and three opaque red ovals scattered throughout the view. A white arrow begins at a red oval outline toward the top left, and a second toward the bottom right, also piercing an oval outline.

The middle black square is slightly larger. There are two labels below this box. Next to an opaque light blue oval is text that reads "Relatively nearby galaxy." Beneath that and next to a slightly larger, dotted light blue circle is text that reads "Gravitational lensing influence of foreground galaxy." The second black box contains five opaque light blue ovals. Each is surrounded by a light blue dotted circle. The first white arrow continues to follow a straight path, piercing the top left galaxy, between the dotted circle and the opaque central oval. The second arrow pierces a galaxy at the bottom right in the same location.

The largest black box at right has one label below it that reads "Observed by Webb." This black box shows five galaxies that are light blue and completely opaque with white at the center. They are at the same positions as the blue galaxies in the middle panel. Three red galaxies with small white centers, which are also opaque, appear at bottom center and top right. They are at the same positions as the opaque red galaxies in the first panel. The first line ending in an arrow points to an orange circle, which is also opaque, that is immediately to the right of a blue galaxy at top left. They barely touch. The second line, which also ends in an arrow pointing right, points to an orange opaque circle that sits to the left of a blue galaxy at the bottom right. The two orange galaxies are at the same positions as the outlined galaxies in the first panel with white arrows.

The lines indicate that when light from a galaxy that would otherwise be too faint to detect passes through the area of gravitational lensing influence of a foreground galaxy, it will make the faint galaxy observable by Webb.

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A square graphic breaks down how gravitational lensing by foreground galaxies influences the appearance of far more distant background galaxies.