This week we saw a new twist in the funding issues of the Arecibo Observatory. On Tuesday, July 12, Subcommittee on Space and Subcommittee on Research and Technology of the US Congress heard a panel of experts on astronomy, astrophysics, and astrobiology. The witnesses were Director of NASA's Astrophysics Division Dr. Paul Hertz, National Science Foundation (NSF) Director of Division of Astronomical Sciences, Dr. Jim Ulvestad, Chair of Astronomy and Astrophysics Advisory Committee Dr. Angela Olinto, Breakthrough Listen Advisory Committee and San Diego's Center for Astrophysics and Space Sciences member Dr. Shelley Wright, and President of American Astronomical Society Dr. Christine Jones. So whatever this folk says in front of US congress, you better believe it, right?
began with Dr. Hertz's overview of the current stage of astronomical research, such as studies of supermassive black holes and increasing research of exoplanets as our technologic abilities finally enable studying them. Dr. Ulvestad stressed the NSF's role as a leader in enabling the research of all magnificent galactic and extragalactic objects, praising especially Large Synopic Survey Telescope (LSST) and Atacama Large Millimeter/submillimeter Array (ALMA):
Search of Extra-Terrestrial Intelligence (SETI) and radio telescopes such as Parkes and Greenbank in addition to the new Chinese FAST as irreplaceable instruments for finding the ET.
After the initial testimonies, the panel was interviewed about current or near-future missions, observatories and instruments of interest. Arecibo Observatory funding was discussed as well. Republican representative Mr. Rohrabacher had heard about NSF's plans for mothballing Arecibo Obsevatory (AO) and raised his concerns for whether there are currently any other assets that enable us to find and predict the paths of potentially hazardous objects as accurately as AO.
"So first I'll say, we haven't made any decisions about what the future of Arecibo is, we're studying a variety of options, but in terms of detecting objects far out, what you really need for that is a survey telescope with a very wide field of view, which Arecibo is not. Arecibo's radar can be used to characterize the properties of an object, say, an asteroid that is already known about that you can point at, but in terms of NSF investment, the LSST which can survey the sky --" Here Mr. Rohrabacher interrupts Dr. Ulvestad asking if LSST is already operational to handle the asteroid detections. Dr. Ulvestad confirms that LSST is not yet fully operational and continues:
"Well, Arecibo, as I said, is not a survey telescope, so it can only do radar characterization of asteroids that are already known about."
Mr. Rohrabacher tries to remind that radar calculations can also predict if the asteroid will actually impact the Earth. Believe it or not, Dr. Ulvestad denies the truth:
"No, what they actually do is radar assessments of what the composition of the object is, if it's a rubble-pile instead of solid iron mass have a very different impact. -- It's involved with tracking [the object] but tracking can also be done with optical and infrared telescopes."
Mr. Rohrabacher asks directly: "So your testimony today is that Arecibo is not providing at this time a service that is not being provided by someone else?"
"So as I mentioned, the radar characterization is unique to Arecibo, the characterization of the properties of an asteroid. Now NASA also has a radar at Goldstone, but that's a smaller dish so its reaching to the distance is not as far", Dr. Ulvestad replies.
"Right, so the actual being able to determine the, as you say, what the composition is, is not something that tells us whether or not that is a threat to the Earth?"
"It tells us something about whether it's a threat to the Earth. I think that it doesn't tell us uniquely about its path."
The answer of Dr. Ulvestad (and the rest of the panel) almost made us – Patrick, Ed and myself – choke on our drinks when we heard it the first time while enjoying our lunch. So, if that's what the NSF's Director of Division of Astronomical Sciences thinks, no wonder why the NSF is planning to divest the AO funding. Unfortunately, what Dr. Ulvestad thinks is not completely true. The main task of the planetary radar group of the AO is to refine the orbits of newly found asteroids so that they don't get lost or, if they are potentially hitting the Earth, increase the accuracy of the orbit solution as was done in the case of Apophis. We can also study the composition in terms of how metallic an object is, as Dr. Ulvestad says, or how rough the surface is, or tell it's spin properties, but those are all secondary objectives. Goldstone can do that as well, but it's part of the Deep Space Network and therefore used for many other tasks, in addition to being much smaller, as was mentioned.
This also raises a question of does the NSF's Director of Division of Astronomical Sciences not understand how radar works, or is he being deliberately misleading (which would be perjury) to promote the LSST? Yes, LSST will have the world's best CCD camera, but it is still a ground-based optical/near-infrared telescope that cannot determine the distance of an asteroid without multiple observations. LSST will not have enough time on it's schedule to concentrate on tracking asteroids. AO needs one successful detection of the asteroid to determine the distance to a few tens of meters at best, and the radial velocity to millimeters per second. NASA has stated that they don't send spacecrafts to asteroids that are not been radar-detected.
Even if LSST did concentrate on asteroid surveying, it will very likely not discover thousands of potentially hazardous asteroids (PHAs) and determine their orbits super accurately. Near-Earth asteroids, possibly, but not PHAs. Currently, more than 14,500 near-Earth asteroids have been discovered and only slightly over 1,700 of those are PHAs. The size limit for a PHA is 150 meters in diameter. Pan-Starrs and Catalina Sky Survey combined discover roughly 1000-1500 near-Earth asteroids per year, but their primary objective is to look for asteroids while LSST will also have a variety of other objectives.
I can't stress enough that there's absolutely no point of knowing about existence of potentially hazardous asteroids if we don't know exactly where they are and where they are going.
Basically, NSF wants to rip $8 million dollars from Arecibo (or at least $4 million). With only $1 million more, the telescope could even be improved. In total, NSF budget is nearly $250 million. I also want to remind that in 2014 NSF wanted to divest from the Greenbank radio telescope, which was fortunately saved by the US congress. NSF says that even the largest single-dish radio telescope that is currently in open use for any US scientist and the better one of the only two systematically radar transmitting radar telescopes in the world is not doing something that someone else could do, while at the same time they are investing $27.5 million to another optical ground-based telescope. I'm not saying that LSST would not be better than many other optical telescopes, but this ratio of cost to importance is as ridiculous as having an NSF's Director of Division of Astronomical Sciences who does not understand how a radar works.
Last year the director of AO was basically forced to quit because he had criticized NSF. I'm not sure if NSF could kick me out for writing this post, especially because my funding comes from NASA instead of NSF, but in general the AO employees are in a difficult position between keeping our jobs making great science/defending the planet and a funding agency that claims that a variety of options regarding the observatory future is studied but obviously seems to have made up its mind of the most favorable option. AO does not want to start a war with NSF but neither is it right to spread false information about the important work that is done. Our only hope is that the US Congress can see through that false information or that another party comes to our rescue.
What made the hearing even worse was the ego stroking of the other panelists. Dr. Hertz from NASA's Astrophysics Division "certainly agrees with everything that Dr. Ulvestad said". He also reminded that, unlike Arecibo that's sitting in a valley the way it does, Goldstone can be pointed (I guess he meant that it can be steered; telescope that can't be pointed really wouldn't see anything at all). Also Dr. Olinto reinforced this "fact". We should seriously invite all these people to visit the observatory to show that we can actually point our radar beam to a lot more than one point in the sky!
My compliments to Mr. Rohrabacher though for appearing smarter than the five doctors sitting opposite to him.