The Uppsala dome on the left with University of NSW APT telescope with roll-off roof to the right, and UKST in the
background
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Location
SSS (IAU observatory code E12) is located at Siding Spring Observatory (IAU observatory code 413) at Longitude 149.1 East,
Latitude 31.3 South, Altitude 1150m ASL, approximately 400km NorthWest of Sydney NSW, Australia.
Mission
The mission of the Siding Spring Survey is to contribute to the inventory of near-earth objects (NEOs), or more
specifically, the potentially hazardous asteroids (PHAs) and comets (PHOs) that may pose a threat of impact and thus harm to civilization.
The identification of the iridium anomaly at the Cretaceous-Tertiary boundary (Alvarez et al., 1980) and associated Chicxulub impact
crater (Hildebrand et al., 1991) and perhaps recently the Australian Bedout crater (Becker et al., 2004) associated with the Permian-
Triassic "great dying" (although the presence of shock metamorphism has not yet been adequately demonstrated), strongly suggests
that impacts by minor planets play an important role in the evolution of life. These are a natural result of the accretionary process that
formed the Earth and planets. Indeed, the 1994 impact of D/Shoemaker-Levy 9 on Jupiter provided tangible evidence of this. Although the
collision frequency is much lower than in the past, the question is not whether there will be other impacts, but when.
Aside from the uncertainty of an asteroid impact, and whether there are means of mitigating them, we now have the technology to inventory
the NEO population - the first element in assessing the threat. Given the catastrophic consequences of a collision with a large object, it
would be irresponsible not to carry out an inventory now. The NEO Observations Program (NEOO) is a result of a 1998 US congressional
directive to NASA to conduct a program to identify 1 km. or larger bodies to an estimated 90 percent confidence level or better. In
addition to creating an inventory of potentially hazardous objects, there are numerous scientific benefits of surveying for NEOs. Those
include improving the known population distribution in the main belt, finding the cometary distribution at larger perihelion distances,
determining the distribution of NEOs as a product of collisional history and transport to the inner solar system, and identifying
potential targets for flight projects.
The Catalina Sky Survey (CSS) and its affiliated Siding Spring Survey (SSS) are carrying out sustained, productive searches for NEOs,
contributing to the congressionally mandated goal of obtaining an inventory of better than 90% of the previously mentioned NASA goal.
Every month, wide-angle surveys cover the observable sky to R ~19.5. Larger apertures are needed to extend the search volume to
larger distances, even if their smaller fields limit coverage to the ecliptic region. In addition to other upgrades from past NEOO grants,
the Catalina group have commenced operating a one-square-degree prime focus camera on the underutilized 1.5-m Mt. Lemmon telescope north of Tucson
to help fill this need.
Simply creating an inventory of NEOs is a necessary, but insufficient component of fully realizing the NEOO program goal. Assessing the
threat posed by a PHA requires predictions of its impact energy. This requires knowing both the mass and velocity of the impacting object,
or more precisely, its size, density, and velocity. Accurately determining size requires knowing the shape and albedo. Therefore, in
parallel with deep survey activities, we be soon using the Mt. Lemmon 1.5-m telescope obtain physical data of objects that will help
complete our understanding of the threat posed by newly-discovered and multiple-return NEOs.
Based on the CSS Mission page
Staff
Currently there are two local staff; Robert McNaught and Gordon Garradd. However, the team at the Catalina
Sky Survey (CSS) are responsible for the maintainance of the software and were heavily involved in the initial setup. In
particular, Steve Larson (the PI) and software engineers Ed Beshore and Eric Christensen have visited SSS on a number of occasions to
bring the project on line or make major upgrades.
Rob McNaught (left) and Gordon Garradd (right) in front of the Uppsala dome and office (right) in 2003. To the left is the
University of NSW APT and in the background is one of the ROTSE telescopes of the University of Michigan, operated in conjunction with the
University of NSW
Email: Rob McNaught - rmn@mso.anu.edu.au.nospam
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