The Clay Center Observatory’s diffraction-limited optical system and extensive instrumentation have attracted the interest and participation of numerous research teams. Here are highlights of past and current research activities;
Asteroid 2008 TC3
On the night of October 6, 2008, a telescopic observer atop Mount Lemmon, Arizona, discovered that an SUV-size asteroid fragment would slam into Earth’s atmosphere over northern Sudan just 19 hours later. this marked the first and only time that an asteroid had been discovered with a certain probability of striking Earth. Fortunately, the object — designated 2008 TC3 — was far too small to reach the ground intact. Instead, it exploded at a height of about 23 miles (37 km), lighting up the predawn darkness and frightening thousands of Sudanese making their way home after morning prayers.
In the hours before it struck, Marek Kozubal and Ron Dantowitz imaged 2008 TC3 using the 0.64-m telescope at the Clay Center Observatory. Because of the asteroid’s rapid motion across the sky, Kozubal needed to write special tracking software so that the telescope could remain locked on the target. They acquired panchromatic images at 4-second intervals from after sunset until the object entered Earth’s shadow about 2 hours later — some 1,700 images in all. From this unique light curve, Kozubal derived the object’s absolute magnitude and its changing apparent magnitude over time. Asteroid specialists used the observatory’s unmatched high-quality observations to determine that 2008 TC3 exhibited spin periods of 99.173 and 96.988 seconds, corresponding to rotation and precession, respectively.
The research and data analysis of this asteroid have been published in Meteoritics & Planetary Science as Photometric Observations of Earth-Impacting asteroid 2008 TC3 and The Shape and Rotation of Asteroid 2008 TC3. The results from this work were also presented at the Division of Planetary Sciences meeting of the American Astronomical Society in October, 2009, titled Photometric Observations of Asteroid 2008 TC3 and A Non-principle Axis Rotation of 2008 TC3. Additionally a paper was published in Nature titled The Impact and Recovery of asteroid 2008 TC3.
Reentry of Cargo Spacecraft “Jules Verne”
September 29, 2008 • Collaborators: NASA, European Space Agency
A trio of observers representing the Clay Center Observatory joined other scientists aboard two aircraft high over the South Pacific Ocean. Their mission was to record the dramatic nighttime reentry of a large European spacecraft called Jules Verne as it slammed into Earth’s atmosphere at more than 8 km (5 miles) per second. Also known as an Automated Transfer Vehicle, Jules Verne had been docked to the International Space Station for several months. Roughly the size of a large bus, it already weighed 20 tons before astronauts stuffed it with another 2½ tons of garbage and waste.
Aboard one chase plane, a commercially owned Gulfstream V, were Clay Center faculty members Ronald Dantowitz and Marek Kozubal. They operated a bank of eight sensitive cameras and spectrographs, built at the school, to record the temperature and composition of superheated fragments created during the spacecraft’s fiery atmospheric plunge. Undergraduate student David Sliski operated an additional camera and spectrograph on the second aircraft, a DC-8 that NASA has converted into an airborne laboratory.
As instruments continuously tracked Jules Verne’s final moments, the spacecraft first broke into three large chunks before exploding violently into hundreds more. Observations by the observatory’s spectroscope’s show a clear sequence of changes as various parts of the spacecraft glowed incandescent from the heat of atmospheric friction. Months later Dantowitz and Kozubal presented their findings at a meeting of European scientists and engineers in Norrdwijk, the Netherlands.
Aurigid Meteors Observing Campaign
September 2007 • Collaborators: NASA-Ames Research Center
After theorists predicted that the normally weak Aurigid meteor shower would intensify dramatically on September 1, 2007, Peter Jenniskens of NASA’s Ames Research Center mounted a campaign to study these brief flashes from two research aircraft flying high above western North America. For a few brief minutes, Earth would through a stream of debris shed from Comet Kiess (C/1911 N1) 2,000 years ago during its one and only pass through the inner solar system. Obtaining spectra as these meteoric crumbs incinerated themselves would provide a unique opportunity to learn more about primitive comets and the composition of the early solar system.
At Jenniskens’ request, Ron Dantowitz joined the research team that crammed the windwos of two jets with dozens of spectrographs, intensified video cameras, and even a 100,000-frame-per-second ultraviolet spectrograph. The burst of meteors arrived as predicted, and Dantowitz was rewarded when a bright meteor splashed a brilliant set of emission lines across his computer screen — exactly what the team had hoped to acquire.
Never before had anyone successfully predicted a meteor shower from a long-period comet. The Aurigids’ on-time arrival validated models of how dust and debris travel through our solar system. By being in the right place, at the right time, the researchers had vicariously sampled the crust of a primitive comet.
Fourier Transform Spectrograph
2006 – 2009 • Collaborators: United States Naval Observatory
The Fourier transform spectrograph has produced some of the most detailed stellar spectra ever seen by astronomers, and may potentially allow the Clay Center telescope to discover new planets around other stars. The spectrograph at the Clay Center Observatory can measure radial velocities of stars with a precision of less than two meters per second, which makes Dexter and Southfield Schools the home of the one of the most precise planet-finding telescopes in the world. Dr. Arsen Hajian, the USNO astronomer, visited the Clay Center several times during the fall and has given short presentations to the upper school science classes. In January 2006 the first results of the USNO FTS project at the Clay Center were presented in a paper at the 207th American Astronomical Society Meeting in Washington, DC.
Stardust Reentry Capsule
January 2006 • Collaborators: NASA-Ames Research Center
Because of their ground-breaking work in high-speed telescope tracking software at the Clay Center, they were invited to work with NASA to provide images from the ground during the phase of reentry when the spacecraft reaches high temperatures because of friction with the atmosphere.
The Stardust mission is the first one created to gather material from a comet in deep space and return it safely to Earth. The Stardust spacecraft, launched in February 1999, has traveled over 3 billion miles for almost 7 years. It released the capsule with the comet material just above the atmosphere, and the capsule entered the Earth’s atmosphere in the early morning of January 15th at a speed of 28,600 miles per hour. At an altitude of 10,000 feet parachutes began to deploy to slow the capsule down so that it could land safely in a desert area of Utah. Clay Center astronomers captured the descent with cameras and spectrographs.
Laser Project with International Space Station
March-April 2005 • Collaborators: NASA-Johnson Space Center
This original research project involved researchers at NASA; the Italian, Russian, and European Space Agencies; University of Rome; U.S. Naval Observatory; and University of Maryland. A 10-watt laser was fired from the Clay Center’s main telescope to a window on the International Space Station, 400 km (250 miles) away, and the reflected light was used to build an image of the spacecraft. The purpose of this experiment was to develop a system that will allow telescopes on Earth to spot damage on satellites in space, with the goal of preventing another tragedy such as the one that destroyed the Space Shuttle Columbia in February 2003.
Dexter and Southfield high-school students met with astronomers and scientists from Italy and Maryland and learned about the physics of the project. The students also participated in one of the laser firings. An article and a photograph of the laser appeared in the Boston Globe on May 15, 2005.
SpaceShipOne Telescopic Tracking
September-October 2004 • Collaborators: Scaled Composites
The world’s first privately built spaceship made two trips into space on September 29 and October 4, 2004, from a location in the Mojave desert in California. Funded by Paul G. Allen, co-founder of Microsoft, and built by Scaled Composites LLC, SpaceShipOne traveled 100 km (63 miles) above sea level and returned safely to Earth. Nearly every news agency and newspaper in the world covered these historic flights, yet only one group was able to track and photograph the spaceship with high-resolution telescopes. That was the team from the Clay Center Observatory, whose groundbreaking work in high-speed tracking software had attracted the attention of Burt Rutan of Scaled Composites.
The observatory’s portable tracking system provided major television networks with a live video feed that was seen by an estimated one billion people worldwide. On-screen credit read “Dexter and Southfield Schools,” along with the school logos. It represented a unique public-relations event for the schools, as cameras assembled and operated by the observatory’s staff captured a new chapter in the history of human space flight.