Projects: Shoemaker NEO Grants
Updates on the 2007 Shoemaker NEO Grant Recipients
June 27, 2008
Mount Matajur Observatory
Shoemaker NEO Grant winner Giovanni Sostero of the Remanzacco Observatory
reports that a new observatory on Mount Matajur, 1,320 meters above
sea level, was recently completed, with observations underway from
May 2008. Credit: Giovanni Sostero / Remanzacco Observatory |
Amateur astronomers play a critical role in retiring the risk of impact from
near-Earth objects. When the Shoemaker NEO Grant program began in 1997,
the focus was on finding previously undiscovered objects one kilometer in
diameter and larger. Thanks to professional NEO survey programs like
LINEAR (the Lincoln Near-Earth Asteroid Research program run by MIT’s
Lincoln Laboratories) and the Catalina Sky Survey (run from the University
of Arizona’s Lunar and Planetary Laboratory), the goal of discovering
the vast majority of large NEOs is within reach, and the focus of the Shoemaker
NEO Grant Program has shifted to astrometric follow-up and physical studies. Astrometric
follow-up observations extend the time and space over which an object's position
is mapped, enabling its orbit to be determined with higher certainty, while
physical studies help scientists understand the composition, construction,
origin, and orbital evolution of these bodies. Physical studies also
will be critical for evaluating methods for any future necessary asteroid
mitigation (for example, moving an asteroid’s orbit to avoid Earth).
Tracking Faint Objects
Several of the 2007 Shoemaker NEO Grant winners used their funds to purchase
CCD cameras capable of capturing large swaths of the sky or imaging very faint
objects, or both. Robert Holmes, of the Astronomical Research Institute
in Illinois, reports that with the new CCD camera purchased with NEO grant
funds, 84,600 images of near-Earth objects were taken in the year from June
1, 2007 to May 31, 2008. From these, the Astronomical Research Institute
reported a staggering 5,835 targeted measures of comets and near-Earth asteroids
to the Minor Planet Center. The faintest object Holmes captured on camera
was 2001 SD170, observed at an unfiltered magnitude of about 23.5.
In Tahiti, Jean-Claude Pelle also used his NEO Grant award to purchase a
CCD camera permitting him to capture a view of the sky 39 arcminutes square. This
relatively broad field of view has facilitated Pelle's efforts to follow
up on just-discovered NEOs whose orbits were only observed over a very
short arc (often less than one hour) and so suffer from large uncertainties
in their position. By aggressively following these recently-discovered
objects, Pelle and his collaborators at Southern Stars Observatories have
multiplied the length of the known arcs of some bodies by factors as large
as 20. The
wide field of view also brings a collateral benefit: many other objects
are also often present in a single image. As a by-product of near-Earth
object follow-up, Southern Stars Observatories workers have discovered
150 discoveries of main-belt asteroids.
The benefit of the NEO Grant to Giovanni Sostero and his coworkers
at the Associazione Friulana di Astronomia e Meteorologia in Remanzacco, Udine,
Italy has been to improve their computing power with two new PCs, speeding
up their reaction times in following up new, fast-moving objects. His group now
conducts astrometric and photometric follow-up from two sites in Italy, a
permanent observatory at Remanzacco and a site for their portable telescopes
in Comeglians, with a third position under construction at Mount Matajur,
1,320 meters above sea level. They and also observe remotely, from New
Mexico and Australia. In a period of fifteen months, Sostero's group has
confirmed 27 NEOs to be comets, has performed confirmation observations on
the discoveries of nearly 50 NEOs (some of them very faint, at magnitudes
near 21), and has recovered seven periodic comets.
Brian Warner, at the Palmer Divide Observatory in Colorado, has put his Shoemaker
NEO Grant to slightly different use. His grant allowed him to purchase
a second telescope, which he employs to do photometry (studies of how the
brightness of asteroids vary with the observing angle and the asteroid's rotation),
which, in turn, helps to provide information on the size and shape of larger
asteroids. Although these studies don't directly address the problem
of whether a given asteroid will or won't hit Earth, they provide important
data to the broader research into the range of sizes and shapes of the asteroid
population, and into studies on YORP, the various ways that asteroid orbits
change as sunlight is absorbed, reflected, and re-radiated by spinning, odd-shaped,
inhomogeneously colored asteroids. As a by-product of his studies,
Warner has discovered that at least a dozen asteroids are binaries. Don
Pray of the Carbuncle Hill observatory has been performing similar photometric
studies, helping to confirm that at least four asteroids are binaries.
Grants Create Cooperation
Although the Gene Shoemaker NEO Grant program now focuses more on follow-up
than discovery, Grant awardees continue to discover new NEOs. But in
order for a NEO discovery to be credited or to figure out if the NEO is a
danger to Earth, there needs to be follow-up tracking of the new object on
subsequent nights, allowing an orbit to be calculated. On July 11, 2007,
Quanzhi Ye of the Lulin Observatory in Taiwan discovered a NEO, 2007 NL1. He
could not perform follow-up observations because of an approaching typhoon,
and in fact it appeared to be a cloudy day across much of Earth. But
he noticed that the southern Pacific Ocean was relatively cloud-free, and
asked fellow 2007 Grant awardee Jean-Claude Pelle in Tahiti to perform follow-up
observations. Pelle was able to obtain them, confirming the discovery
and starting the process of defining the NEO's orbit.
Giovanni Sostero's group has leveraged the $4,400 of their Shoemaker NEO
Grant to win even larger support for their efforts to discover, track, and
study NEOs. Sostero reports that other institutions and foundations
in Italy provided further funding to refurbish their observatories after learning
of the grant award; and that more collaborators joined his team after learning
of the team's work from television and newspaper reports about the NEO threat
and the award of the Shoemaker NEO Grant. "The benefits of the
Gene Shoemaker NEO Grant has exceeded our expectations," Sostero said.
Bringing the Public Along for the Ride
Though not required to do so, many of the Shoemaker NEO Grant winners have
independently embarked on programs to educate their communities about the
night sky and the hazard of potential asteroid impact. Some also involve
classrooms around the world in the work to discover and track potentially
hazardous objects.
For example, the Astronomical Research Institute in Illinois is participating
in the worldwide "Killer Asteroid Project," which raises awareness
about the threat of near-Earth objects to teachers and students around the
world. Holmes says, "Each night up to one gigabyte of data is
imaged using The Planetary Society SBIG STL-1001E CCD camera, uploaded to
the Internet, and made available to high schools, colleges, and universities
for use in their classrooms within 5 hours of acquisition. In May 2008,
the Astronomical Research Institute presented more than 450 awards to schools,
teachers, and students in nine countries including China, Germany, Italy,
Japan, Morocco, Poland, Portugal, Russia, and the United States."
Students conducting Near Earth Object Observations at Shizuoka University in Japan
Credit: Robert Holmes, Astronomical Research Institute
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For Eric Allen of Quebec, the publicity generated by his grant
award gave him the argument he needed to convince his superiors to permit
him to open the observatory to the public for the first time since 2003. Now
the observatory is open to the public six nights a week, and Allen educates
the visitors about the night sky and NEOs. He was also interviewed for
a Discovery Canada documentary on the 100th anniversary of the Tunguska
impact event. His effort to automate his dome (the focus of his grant
award) has been delayed because of the work involved in performing public
outreach, but he expects fully automated observing runs to begin in late
August.
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