NASA has captured an image that looks suspiciously like a Space Invader.
For the uninitiated, "Space Invaders" was a Japanese video game from the 1970's where players were tasked to destroy aliens with a laser cannon. So what is one of these sinister 8-bit creatures doing in a NASA image?
Turns out that the image of the galaxy, named Abell 68, was affected by something called gravitational lensing. Gravitational lensing occurs when light passes by objects that are so large that they alter space-time. This results in a distorted, often stretched image. It is called lensing because of the magnification effect it produces, enlarging distant objects.
"Here, Abell 68, a massive cluster of galaxies, acts as a natural lens in space to brighten and magnify the light coming from very different background galaxies," says Nancy Atkinson of Universe Today. "Just like a fun house mirror, lensing creates a fantasy landscape of arc-like images and mirror images of background galaxies. The foreground cluster is 2 billion light-years away, and the lensed images come from galaxies far behind it."
NASA took the image in infrared using Hubble's Wide Field Camera 3 as well as near-infrared data produced by Hubble's Advanced Camera for Surveys. Gravitational lensing is a useful tool for astronomers, particularly in capturing distant objects.
"These distorted images of distant galaxies are a particularly fine example of this phenomenon," say Hubble officials. "In the middle of the image are a large number of galaxies stretched out into almost straight streaks of light that look like shooting stars."
The Hubble Space Telescope began operating in April 1990. Through five space shuttle missions it has undergone a number of repairs and upgrades. It may remain operational until at least 2018, at which time the James Webb Space Telescope, Hubble's successor, will launch into space.
