Galaxies, Comets, and Stars!
Across the world, children fall asleep under the faint light from glow-in-the-dark astronomy stickers. Though undeniably adorable, these ceiling planetariums are too jam-packed to be realistic. One would never see stars, dozens of spiral galaxies, and comets all at the same time, all shining together from the same patch of sky. Unless, of course, you had Hubble.
On April 30, NASA's Hubble Space Telescope observed Comet ISON, touted to be a spectacular, naked-eye comet in late 2013. In this composite image, Comet ISON is seen splashed out over deep space, embedded in a collage of colorful, distant neighbors.
In reality, the comet is over 70,000 times closer to us than the nearest star and over ten billion times closer to us than the nearest galaxy to the Milky Way. These vast dimensions are lost in this Hubble exposure that visually combines our view of the universe from the very nearby to the extraordinarily far away.
Multiple Hubble observations that were fixed on the background stars were taken in each of two filters (red and yellow-green). Due to its proximity, the comet appeared to move relative to the background objects between each exposure. This effect, known as parallax, caused the comet to become blurred in a summed image of all observations. The blurred comet image was replaced with a single, gray-scale exposure of the comet from one of the observations.
The resultant image is part science, part art. It's a representation of what our eyes, with their ability to adjust to brighter and fainter objects, would see if we could look up at the heavens with the resolution of Hubble. The outcome is a collection of almost all the basic subjects of astronomy — no glow-in-the-dark stickers required.
This view of Comet ISON is one of the original images featured on ISONblog, a new online source offering unique analysis of Comet ISON by Hubble Space Telescope astronomers and staff at the Space Telescope Science Institute in Baltimore, Md. For more on ISONblog, visit: http://hubblesite.org/hubble_discoveries/comet_ison/.
Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)