Giant pinhole camera
Giant pinhole camera to shoot alien worlds
One of the really difficult problems in photo astronomy is that of 'imaging' really faint objects against the great abundance of starlight that is everywhere in the heavens. This a bit like the problem of seeing stars in the sky above a brightly lit city; too much light. For the astronomers that hunt the special class of planets that orbit in'extrasolar' systems in distant parts of the Milky Way, the 'light problem' is totally overwhelming. The principle mechanisms of discovery in extrasolar astronomy have thus been entirely 'indirect'; the presence of a planet orbiting a distant star has been inferred by a wobble in the trajectory of the star; or a periodic dimming of the brightness of the star that has suggested that something is passing in front of the star. No one has yet been able to actually 'image' an "exoplanet" directly. But this is going to change soon, and the tool that will be used to accomplish this seemingly impossible task is a gigantic version of the first camera ever made - the pin hole camera!
Imagine having a photograph of an alien world in a far off solar system, one that shows continents, ice caps, cloud cover, maybe even rivers... thru a pinhole! ...this is going to be fun.
Camera obscura views obscure extrasolar planets
The project is for an orbiting, soccer-field sized "starshade" shaped like a daisy that would funnel light from distant planets between its petals to a second spacecraft trailing 50,000 miles behind. Known as the New Worlds Observer, the project was selected for initial funding by NIAC in 2004 as a giant pinhole camera in space.
The starshade would block out intense light from the parent stars of planets outside the solar system while allowing planet light to creep around the starshade's edge and funneling it into a trailing spacecraft for analysis, Cash said. The observatory would allow scientists to map and catalogue planetary systems around nearby stars -- including those with "warm, close-in orbits around parent stars" similar to Earth and Venus -- to frozen, giant planets at the edges of distant solar systems, he said.
"Using photometry and spectroscopy, we could identify planetary features like oceans, continents, polar caps and cloud banks, and even detect biomarkers like methane, water, oxygen and ozone," said Cash. "We could knock off a new planetary system every week, and we could build it tomorrow using existing technology. It's the kind of mission I dreamed about as a kid, and one that nobody would ever forget."
CU Proposal To Image Distant Planets Is Funded For Second Round Of Study
Alien Planets to Pose for Giant Pinhole Camera in Space
In the fall of 2000, sitting in my apartment in Glenn Dale, MD, I prepared to watch the coming solar eclipse with a shoebox. I opened the blinds on my window, found a comfortable spot on the floor, and propped the box up next to me, one end pointed at the sun. A tiny hole in the end pointed toward the sky allowed just enough light through to form an image of the sun on the inside wall of the box. Thus, without special filters or even a proper telescope, I spent the next hour watching the moon?s shadow creep across the disk of the sun.
I used a pinhole camera; a device known to the ancient Greeks and put to various uses ever since. A small hole punched in the wall of a box -- or a room -- creates an inverted image on a screen of whatever object the camera faces. The pinhole camera, or camera obscura, was used in the Renaissance as a drawing aid. When the screen was replaced by a photographic film, it formed the basis for today?s handheld cameras.
Now, a project funded by NASA?s Institute for Advanced Concepts (NIAC) could launch the humble pinhole camera into the sky. Dubbed the New Worlds Imager (NWI) and led by Dr. Webster Cash of the University of Colorado at Boulder, the goal is to use a large-scale camera obscura to obtain the first pictures of exosolar planets -- worlds from beyond our solar system.
NASA - Alien Planets to Pose for Giant Pinhole Camera in Space
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