Featured Research

from universities, journals, and other organizations

Tiniest Of Space Bodies To Get Close Examination

Date:
June 4, 1998
Source:
NASA/Marshall Space Flight Center--Space Sciences Laboratory
Summary:
As astrophysicists turn their telescopes to probe the origins of stars and planets, they will start giving more attention to the smallest of astronomical bodies - dust particles - which both make them and also obscure the view.

As astrophysicists turn their telescopes to probe the origins of stars and planets, they will start giving more attention to the smallest of astronomical bodies - dust particles - which both make them and also obscure the view.

"We're developing an experimental method to measure scattering and extinction cross sections for dust particles in the solar system," said Dr. James Spann of NASA's Marshall Space Flight Center. Spann is leading development of the Dusty Plasmas Laboratory. In it, a single grain of dust is suspended by static electricity while it is bombarded with electrons and light and its reactions measured.

Dust might seem like a lowly object to receive such attention, but it's an important factor in the vacuum between planets and stars. Dust particles drift through space where they absorb and scatter light.

How rapidly they extinguish light over the millions or billions of miles of "empty" space determines how visible the source will be.

"We think we can devise an experiment that replicates the environment of these particles in planetary or preplanetary atmospheres," Spann said.

The observations planned by Spann and another Marshall scientist, Dr. Mian Abbas, will balance between two well known areas of optics, Rayleigh scattering and geometrical optics. Rayleigh scattering, where an object is much smaller than a wavelength of light, is why the sky is blue. Geometrical optics, where an object is much larger than a wavelength of light, is why lenses bend light.

Between these two is the Mie theory covering light scattered by objects that are about the same size as a wavelength of light.

"It's a very beautiful theory," Spann said. "It's incredibly fascinating for a lot of reasons."

One of those reasons is how infrared light is scattered by dust grains which are much larger than visible light, but about the size of longer-wavelength infrared.

Little work has been done in this area - it's mostly extrapolated from visible light observations or from the bulk properties of dust. The work won't be easy.

"Part of the challenge in this experiment is that these grains are irregularly shaped," Spann explained. "Unless you're dealing with liquid droplets, which are spherical, the orientation of the grain is important." Thus, a grain may be larger than a wavelength of light across its length, but much smaller across its width.

Interplanetary dust particles range from 5 to 100 microns in length; 30 microns is typical. They can be spherically or irregularly shaped, and made of silicate or carbonaceous materials. In total, it's a complex range of particles that Spann and Abbas will try to measure in detail.

With the Dusty Plasmas Laboratory, Spann and Abbas will be able to make unique measurements of how dust particles polarize light - convert its vibrations so they are all in one plane - and the angles at which the light is reflected.

"We can make significant contributions to planetary missions," Spann said.

"All planetary atmospheres have dust, aerosols and grains hanging in the atmosphere." Even Mars with its tenuous atmosphere has months-long dust storms that obscure the surface.

Results from the Dusty Plasmas Laboratory will also help in understanding what is seen in the thick dust clouds in deep space where planets are slowly condensing. Infrared telescopes can see little of what is happening because the view is obscured by the very dust that eventually will become planets, comets, asteroids, or just the dust that, as in our solar system, reflects sunlight back to give the sky a slight glow along the plane of the planets.

Editor's Note: The original news release, with related links and images, can be found at http://science.msfc.nasa.gov/newhome/headlines/ast29may98_1.htm.


Story Source:

The above story is based on materials provided by NASA/Marshall Space Flight Center--Space Sciences Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Marshall Space Flight Center--Space Sciences Laboratory. "Tiniest Of Space Bodies To Get Close Examination." ScienceDaily. ScienceDaily, 4 June 1998. <www.sciencedaily.com/releases/1998/06/980604072025.htm>.
NASA/Marshall Space Flight Center--Space Sciences Laboratory. (1998, June 4). Tiniest Of Space Bodies To Get Close Examination. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/1998/06/980604072025.htm
NASA/Marshall Space Flight Center--Space Sciences Laboratory. "Tiniest Of Space Bodies To Get Close Examination." ScienceDaily. www.sciencedaily.com/releases/1998/06/980604072025.htm (accessed August 23, 2014).

Share This




More Space & Time News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Newsy (Aug. 21, 2014) Russian cosmonauts say they've found evidence of sea plankton on the International Space Station's windows. NASA is a little more skeptical. Video provided by Newsy
Powered by NewsLook.com
Space to Ground: Hello Georges

Space to Ground: Hello Georges

NASA (Aug. 18, 2014) Europe's ATV-5 delivers new science and the crew tests smart SPHERES. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
Tiny Satellites, Like The One Tossed From ISS, On The Rise

Tiny Satellites, Like The One Tossed From ISS, On The Rise

Newsy (Aug. 18, 2014) The Chasqui I, hand-delivered into orbit by a Russian cosmonaut, is one of hundreds of small satellites set to go up in the next few years. Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, August 15, 2014

This Week @ NASA, August 15, 2014

NASA (Aug. 15, 2014) Carbon Observatory’s First Data, ATV-5 Delivers Cargo, Cygnus Departs Station and more... Video provided by NASA
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins