Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/tpfiles/NolantagR2097tp.ps Дата изменения: Mon May 9 19:52:00 2005 Дата индексирования: Sat Dec 22 21:12:19 2007 Кодировка: Поисковые слова: asteroid

Proposal Identification No.: R2097 Date Received: 2005­May­04 11:33:32
Technical Page
Proposal Type: Urgent
General Category: Planetary Radar
Observation Category: Solar System
Total Time Requested: 12 Hours
Proposal Title: Radar Observations of asteroids 2005 ED318
ABSTRACT:
Near­Earth asteroid 2005 ED318 approaches to within .016 AU of the Earth in May 2005. This 350­m ``Potentially
Hazardous'' object presents a high­resolution (7.5­m) imaging opportunity (the highest SNR opportunity this year).
Objects in this size range are near the ``strength­gravity transition'', which is critical to our understanding of
meteorite delivery and asteroid hazard mitigation, and we need to use every opportunity to image these targets.
Radar imaging can help determine the internal structure by giving us information about the size, spin rate and
even density in the case of binary systems. Asteroid 2005 ED318 was discovered by the LONEOS asteroid search
program, but its orbit was initially uncertain, so we delayed proposing until we were sure of its position. Nothing is
known about the physical properties of this object other than its absolute magnitude of 20, which suggests that its
diameter is within a factor of two of 350 m. Conservatively assuming a rotation period of 2 h, we should be able to
obtain S/N of about 10000 per run at closest approach, and obtain images at 7.5 m resolution during its approach
to 0.016 AU of the Earth in May 2005. We will need several days of observation to obtain good rotational coverage.
Imaging at 7.5m resolution will allow good determination of the overall shape of the object, and will resolve large
surface features. It will also allow detection of satellites, if any exist.
Name Institution E­mail Phone Student
Michael C Nolan Arecibo Observatory nolan@naic.edu no
Service Observing Request Remot e Observing Request
X None X No
All of the observing run. Maybe
Part of the observing run. Yes
Queue Observing
Instrument Setup
S­Band radar S­band receiver
Atmospheric Observation Instruments:
1

Special Equipment or setup: none
RFI Considerations
Frequency Ranges Planned
2