Near Earth ObjectsOverview of the NEO Observation Program
Lindley JohnsonPlanetary Science Division
NASA HQ21 June 2012
US component to International Spaceguard Survey effortHas provided 99% of new detections of NEOs since
1998
Began with NASA commitment to House Committee on Science in May, 1998– Averaged ~$4M/year Research funding 2002-2010– 400% plus-up to $20M in President’s 2012 budget submittal
Scientific Objective: Discover 90% of NEOs larger than 1 kilometer in size within 10 years (1998 – 2008)
NASA Authorization Act of 2005 provided additional direction)“…plan, develop, and implement a Near-Earth Object Survey program to detect, track, catalogue, and characterize the physical characteristics of near-Earth objects equal to or greater than 140 meters in diameter in order to assess the threat of such near-Earth objects to the Earth. It shall be the goal of the Survey program to achieve 90 percent completion of its near-Earth object catalogue within 15 years [by 2020].
NEO Observation Program
2
NASA’s NEO Search Program(Current Systems)
LINEAR
MIT/LL Soccoro, NM
Catalina SkySurvey
UofAZArizona & Australia
Minor Planet Center (MPC)• IAU sanctioned• Int’l observation database• Initial orbit determinationwww.cfa.harvard.edu/iau/mpc.html NEO Program Office @ JPL• Program
coordination • Precision orbit
determination • Automated
SENTRY http://neo.jpl.nasa.gov/
Pan-STARRS
Uof HIHaleakula, Maui
NEO-WISE
JPLSun-synch LEO
3
End ofOperationsFeb 2011,AnalysisOf Data
Continues
Known Near Earth Asteriod Population
Start of NASA NEO
Program
Known Near Earth Asteroid Population
5
Spaceguard Survey Catalog ProgramCurrent Spaceguard Survey Infrastructure and Process
Survey,Detect,
& Report
Correlate, DetermineRough Orbit
PossibleNew PHO?
RoutineProcessing
PublishResults
Yes
PotentialImpact?
ResolveResult
Differences
PublishResults
No
Precision Orbit and Follow Up Observations
Impact Still
Possible?
Observations andUpdate Orbit
Publish/UpdateResults
No
No
Yes
Yes
Iterate
Survey Systems
Minor Planet Center
JPL NEO Office*
* In parallel with NEODyS
RadarAlerts to NASA HQ
• MPC - PHO of interest
• MPC -possible close approach
• JPL - reports potential for impact
• JPL -publishes probability of impact
6
NASA’s NEO Search Program(Current Systems)
LINEAR
MIT/LL Soccoro, NM
Catalina SkySurvey
UofAZArizona & Australia
Minor Planet Center (MPC)• IAU sanctioned• Int’l observation database• Initial orbit determinationwww.cfa.harvard.edu/iau/mpc.html NEO Program Office @ JPL• Program
coordination • Precision orbit
determination • Automated
SENTRY http://neo.jpl.nasa.gov/
Pan-STARRS
Uof HIHaleakula, Maui
NEO-WISE
JPLSun-synch LEO
7
End ofOperationsFeb 2011,AnalysisOf Data
ContinuesNot Shown – “Follow-up” Projects:
• Several Professional Observatories provide critical data to secure orbits
• Numerous Amateur Astronomers worldwide provide high-precision observations to fill critical gaps
Radar Studies
8
Observations on the limited accessible objects– 20 to 30 NEOs/year from Goldstone and Arecibo– Required for timely precision orbit determination– Characterization with sufficient signal strength
• Shape, spin-state, surface structure
• Satellites (an then derived mass)
Shape, Size of6489 Golevka
Study of Shape, Size, Motion and Mass of 66391 (1999 KW4)
2005 YU55 Approach to Earth Nov. 8, 2011
C-type asteroidDiameter ~400 metersEarth & Moon close approach
Extensive radar, visual and infrared observations were obtained.
Radar Rotation Study of 2005 YU55
Arecibo Observes Newly Discovered 2012 LZ
2012 LZ1 was discovered 10 June 2012 by Siding Spring Observatory in Australia. Classified as a potentially hazardous by the Minor Planet Center because its orbit brings it close to Earth (within 20 lunar distances). Arecibo observed this asteroid on 19 June 2012 to measure its orbit more precisely, and to determine its size, rotation rate and shape.
2012 LZ1 is twice as large as originally estimated based on its brightness, large enough to have serious global consequences if it were to hit the Earth. However, the new orbit solution based on radar measurements shows that this object does not have any chance of hitting the Earth for at least the next 750 years.
2012 LZ1 was found to be about 1 kilometer (0.6 miles) in its largest dimension. It must be quite dark, reflecting only 2-4% of the light that hits it. The image shows that it is fairly spherical and rotates in about 10-15 hours. Image was taken when the asteroid was 10 million kilometers (6 million miles) away, and the resolution is 7.5 m (25 feet).
FY2012 Budget Allocation
Future Survey Capabilities
Space SurveillanceTelescope
14
• DARPA funded project• Designed and built by MIT/LL
• Same division as LINEAR• Located Atom Peak, WSMR, NM • 3.6 meter primary mirror• First Light was Feb 2011• Started 1 year of checkout• Eventual operations by AFSPC• First of 3 to 4 worldwide sites• Serendipitous detection of NEOs in
background mode to space surveillance
Near Term Impact Warning
Proposed ATLAS telescope design
Asteroid Terrestrial-impact Last Alert System –ATLAS*: A project to patrol the entire night sky every night in search of incoming asteroids
A geographically dispersed network (> 6 sites) of small coupled telescopes observing “shallow but wide” to provide more complete sky coverage for warning of near-term impact threats
*Courtesy University of Hawaii Institute for Astronomy
Large Synoptic Survey Telescope
6.4-m effective diameter 10 sq deg field of viewugrizy optical filters18,000 square degrees ++2x15s exposures + 2 more within 60 minutesSurvey entire visible sky every 3-4 days in 2 filters for 10 years
16Initial Operations 2019?
A National Science Foundation Project
Various NEO Survey Telescope Concepts
• A NEO survey telescope will discover highly accessible NEO targets suitable for human exploration in a timely manner.– Optimized for detection of objects in Earth-like orbits within two
years of launch– Launch ready in 4 to 5 years with low risk
• The survey will include follow-up of all detected objects, plus characterization (size, rotation rate) of selected objects.
Study Description Survey Type
Picture Cost
NEOCam/JPL•Sun-Earth L1 orbit•Mid-IR•50cm aperture
Sweet Spot< $500 M (excluding launch)
NEOStar/BATC•Trailing Venus orbit•Mid-IR•50cm aperture
Opposition~ $500 M (excluding launch)
NEST – L2/APL•Sun-Earth L2 orbit•Visible•90cm aperture
Sweet Spot< $500 M (excluding launch)
NEST - Venus/APL
•Trailing Venus orbit•Mid-IR•90cm aperture
Opposition~ $500 M (excluding launch)
Space-based “Sentinel” Concept
Kepler “Sentinel”
≈
19
X
Spitzer
NASA has signed a Space Act Agreement to support B612 Project Sentinel