Determining Asteroid Sizes

Wise_wise2011-nea-b_500

WISE_WISE2011-NEA-b September 29th, 2011

Credit: NASA/JPL-Caltech/R. Hurt (SSC)

This chart illustrates how infrared is used to more accurately determine an asteroid's size. As the top of the chart shows, three asteroids of different sizes can look similar when viewed in visible-light. This is because visible-light from the sun reflects off the surface of the rocks. The more reflective, or shiny, the object is (a feature called albedo), the more light it will reflect. Darker objects reflect little sunlight, so to a telescope from millions of miles away, a large dark asteroid can appear the same as a small, light one. In other words, the brightness of an asteroid viewed in visible light is the result of both its albedo and size.

The bottom half of the chart illustrates what an infrared telescope would see when viewing the same three asteroids. Because infrared detectors sense the heat of an object, which is more directly related to its size, the larger rock appears brighter. In this case, the brightness of the object is not strongly affected by its albedo, or how bright or dark its surface is. When visible and infrared measurements are combined, the albedos of asteroids can be more accurately calculated.

Image Source: /image/WISE/WISE2011-NEA-b

Curator: Wide-field Infrared Survey Explorer, Berkeley, CA, USA

Image Use Policy: Pulic Domain

Image Details

Image Type
Artwork
Subject - Solar System
Interplanetary Body » Asteroid
Wise_wise2011-nea-b_1280
×
ID
WISE2011-NEA-b
Subject Category
A.2.3  
Subject Name
Credits
NASA/JPL-Caltech/R. Hurt (SSC)
Lightyears
Redshift
Reference Url
/image/WISE/WISE2011-NEA-b
Type
Artwork
Image Quality
Good
Distance Notes
Facility
Instrument
Color Assignment
Band
Bandpass
Central Wavelength
Start Time
Integration Time
Dataset ID
Notes
Coordinate Frame
Equinox
Reference Value
Reference Dimension
Reference Pixel
Scale
Rotation
Coordinate System Projection:
Quality
FITS Header
Notes
Creator (Curator)
Wide-field Infrared Survey Explorer
URL
http://wise.astro.ucla.edu
Name
Email
outreach@ssl.berkeley.edu
Telephone
Address
7 Gauss Way
City
Berkeley
State/Province
CA
Postal Code
94720
Country
USA
Rights
Pulic Domain
Publisher
Publisher ID
WISE
Resource ID
Resource URL
/image/WISE/WISE2011-NEA-b
Related Resources
Metadata Date
2012-10-10 18:57:14 -0700
Metadata Version
1.2
×

Detailed color mapping information coming soon...

 

×

There is no distance meta data in this image.