=============================================================================== ==> this proposal requests an upgrade from priority 3 for etedesco.astsfdis =============================================================================== the first two paragraphs below are an updated version of the abstract from the original proposal. the size-frequency distribution of asteroids with diameters < 10 km is essentially unknown. we propose to use isocam (lw10, cam01) in microscanning mode to test current predictions of the number of asteroids per square degree down to sizes below 1 km. our objective is to measure the number of asteroids per unit area of sky observed as a function of ir brightness. (a 1 km main-belt asteroid has a flux density at 12 microns of about 1 mjy.) from these data we will be able to constrain, and perhaps decide among, current estimates for the numbers of asteroids with diameters greater than 1 km. these estimates differ by up to a factor of six. any region of sky along the ecliptic is suitable for this purpose and two such regions were identified during the previous phase 2. each of the selected target regions contain no infrared sources from any of the iras catalogs, including extra galactic, or fss sources. in addition to the solar system science resulting from this study, we will provide data useful for assessing the contamination rate from asteroids in all isocam observations. we will also obtain data from which the brightness and small-scale structure of the zodiacal background can be determined. the additional images obtained by the proposed upgrade improve statistics and probe deeper into the stellar point-source and zodiacal backgrounds. this facilitates identification of asteroids.
Instrument
CAM01
Temporal Coverage
1997-06-10T00:19:15Z/1997-06-10T04:08:59Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, TEDESCO et al., 1998, 'ASTEROID SIZE-FREQUENCY DISTRIBUTION openParPART 2closePar', 1.0, European Space Agency, https://doi.org/10.5270/esa-lfy9l83
