Dr. Peter Jenniskens
If you ever spend a night under the stars watching for meteors, you may want to meet astronomer Peter Jenniskens. He’s an expert on meteor showers and author of Meteor Showers and their Parent Comets, a book containing predictions on what unusual meteor showers to expect in the next 50 years.
Peter is best known for identifying the parent body of the Quadrantid shower, a minor planet called 2003 EH1, and for leading teams of researchers into airborne observations of the 1998 – 2002 Leonid meteor storms. Most recently, he was the lead scientist of NASA’s Stardust Entry Observing Campaign, an airborne and ground effort to analyze the light from the fiery return of the Stardust Sample Return capsule in January, 2006 for clues about the performance of its unique thermal protection system.
In an upcoming project, Jenniskens plans to study the unusual meteor shower taking place on September 1, 2007, when Earth will cross the dust trail of long-period comet C/1911 N1 (Kiess). This brief (less than two hours) shower is visible from the western USA in the early morning hours of a Saturday. Consider stepping outside around 4:36 a.m. pacific time, and joining Peter and his team as they verify when the shower peaks, and look for rare bits and pieces of the comet’s original crust from cosmic ray exposure while in the Oort cloud.
View Peter's write-up on NASA.gov
An Observing Campaign to Study the Entry Radiation & Ablation Products of the Stardust Sample Return Capsule
This cooperative agreement is to support field campaigns, called Hyperseed MAC, to study carbon ablation and shock chemistry in the atmospheric impact of natural meter-sized asteroids, as mimicked by the reentry of the sample return capsules of the GENESIS (Sept. 08, 2004), STARDUST (Jan. 15, 2006), and HAYABUSA (June 2007) missions. These are the first hypervelocity sample return missions since the Apollo era, with Stardust exceeding Apollo entry speeds. Hyperseed will make the SRC reentry into a systems-level field test of the performance of thermal protection materials, and into a controlled experiment to test key processes in the exogenous delivery of prebiotic compounds. The P.I. of this cooperative agreement will be the Principal Investigator and main logistics coordinator, by arranging for available research aircraft, assembling capable researchers and suitable instruments, and contributing to the measurements and data analysis. Measurements will be made of the shock’s radiative heat flux, the body surface temperature, ablation rate, the yield and nature of ablated carbon compounds, and the nature of products from their interaction with the atmosphere. The measurements will be interpreted by models and laboratory experiments developed for the design of thermal protection materials, which will now be applied to the exogenous delivery of organic matter in meter-sized asteroids. This agreement also includes ongoing NASA-sponsored efforts for instrument development and research into the dynamics of meteoroid streams, study of meteor showers, and spectroscopy of meteors.
Work on the GENESIS SRC entry observing campaign was completed. This renewal is to support the second installment of this effort: the STARDUST SRC entry observing campaign, as well as ongoing studies of meteoric matter and meteoroid stream dynamics and evolution.
An Automated Meteoroid Orbit Survey to Measure the Fragmentation History of (Mostly) Dormant Comets in the Near Earth Orbit Population
The primary goal of this proposal is to test the hypothesis that the disintegration of mostly dormant comets is the dominant contribution of dust to the zodiacal cloud. The new insight came from our recent discovery that most major meteor showers have associated weakly active or dormant comets. Few (mostly Halley-type showers) have active parent comets. The established cases point to a formation age in the past 2,000 years from periodic disruptions, rather than from the gradual loss of water vapor. Only eight cases have been established so far. Some 40 associations have been tentatively identified, but their proposed meteoroid streams are not sufficiently well defined.
The main obstacle for translating the observed frequency and dispersion of meteoroid streams at Earth into the frequency and nature of disruptions among (mostly) dormant and weakly active comets is that the streams are not well known. To remedy this, we propose a 3-year meteoroid orbit survey of meteoroids so large (> 0.01 gram) that they dominate the background of grains that had prior collisions with other grains in the solar system and lost their stream association.