Freitag, 25. November 2016 - 08:45 Uhr

Astronomie - Arecibo Observatorium im Focus


USRA Statement in Response to the NSF Draft Environmental Impact Statement (DEIS) for the Arecibo Observatory


November 21, 2016 - My name is Dr. Nicholas White. I am the Universities Space Research Association (USRA) Senior Vice-President for Science. USRA is a nonprofit organization with 105 member Universities all granting PhDs in the Space Sciences. USRA is one of the three partners managing the Arecibo Observatory and is responsible for the Astronomy and Planetary Radar Science at the observatory. I will focus my comments on the Planetary Radar, which the Draft EIS incorrectly summarizes the safety hazard. 

You may have read in the newspapers that last month NASA, the Federal Emergency Management Agency and other government agencies engaged in a planetary protection exercise at the NASA Jet Propulsion Lab to consider the potentially devastating consequences of a 330-foot asteroid hitting the Earth. While this may seem like science fiction, these events are a real possibility. One just has to remember the 2013 Chelyabinsk impact in Russia, which was caused by an object only ~20 meters across. Despite its relatively small size, it caused damage to 7,200 buildings and injured 1,500 people. 

How is this relevant to the discussion today? Well the Arecibo Observatory is the world's most powerful and sensitive radar system which is used to track these killer objects. It is a vital part of our planetary defense system. These hazardous asteroids are found by optical telescopes that scan the sky looking for moving points of light. Once an Asteroid is found Arecibo Observatory within days turns its radar to pinpoint its orbit.  

Arecibo Observatory determines to better than 1 part in 10 million the path of the asteroid and whether it will or will not hit the Earth at some point in the future. Such is the precision Arecibo Observatory can predict the Asteroid orbits decades, even centuries into the future. 

The earlier we can find one of these killer Asteroids, the more time there is to deal with it. Many of these asteroid may go on to orbit the sun for decades, before their paths cross the Earth. In these cases, we will have time to send a spacecraft to deflect it well ahead of time. Even in the worst case scenario, when we find the Asteroid when it is already on a direct collision course, Arecibo Observatory allows us to predict the time and place of its impact and take action to save lives. 

I want to emphasize that there is no other dedicated capability to match Arecibo in the world today. The NASA Goldstone radar is also part of this Planetary Defense network, but has other demands on its time and is not as powerful or as flexible in scheduling. The recently commissioned 500m FAST radio telescope in China has no radar capability and so will not provide a capability to replace Arecibo in this critical area. 

The criticality of Arecibo Observatory has been recognized by the National Academies of Sciences. In a report published in 2010 ["Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies"] the Academy recommended "Immediate action is required to ensure the continued operation of the Arecibo Observatory at a level sufficient to maintain and staff the radar facility". This recommendation has resulted in NASA providing $3.7 million a year, through USRA, to enable this capability, fully one third of the total funding for the observatory. 

In 2005, the United States Congress passed the George E. Brown, Jr. Act that directed NASA to detect, track, and characterize near-Earth objects larger than 140 m in diameter. In 2010, the goals of the George E. Brown, Jr. act were incorporated in the National Space Policy of the United States of America that guides the NASA administrator to pursue capabilities, in cooperation with other departments, agencies, and commercial partners, to "detect, track, catalog, and characterize near-Earth objects to reduce the risk of harm to humans from an unexpected impact on our planet". 

Shutting down the planetary radar operations at Arecibo Observatory will put lives and property at risk. NSF is the Federal steward for this facility and it is USRA's expectation that NSF will maintain the national need to track and characterize Near Earth Asteroids. 

The DEIS fails to note all these critical facts and USRA requests that it be corrected. We suggest that an option be included that continues operation of the facility with the prime purpose to support the NASA funded Planetary Radar.  

I would like to end by saying that USRA, along with our partners SRI and UMET, remain committed to maintaining the full operation of the site. As part of this we are seeking all interested parties who can bring funding to utilize the scientific assets or the site itself to ensure that the NSF preferred option can be realized.

Image of an asteroid that looks like as skull shape

Asteroid 2015 TB145 as seen with Arecibo on October 30, 2015. The image resolution is 7.5 meters (25 feet) per pixel. The vague skull-like image on the left helped earn this asteroid its "Great Pumpkin" moniker. Credit: Arecibo/NASA/NSF.

Quelle: USRA