Peter Jenniskens
Encyclopedia
Petrus Matheus Marie Jenniskens (born August 2, 1962 in the Netherlands) is a Dutch
Dutch people
The Dutch people are an ethnic group native to the Netherlands. They share a common culture and speak the Dutch language. Dutch people and their descendants are found in migrant communities worldwide, notably in Suriname, Chile, Brazil, Canada, Australia, South Africa, New Zealand, and the United...

 astronomer and a senior research scientist at the Carl Sagan Center of the SETI Institute
SETI Institute
The SETI Institute is a not-for-profit organization whose mission is to “explore, understand and explain the origin, nature and prevalence of life in the universe”. SETI stands for the "search for extraterrestrial intelligence". One program is the use of both radio and optical telescopes to search...

 and at NASA Ames Research Center. He is an expert on meteor showers. Jenniskens is the author of the 790 page book "Meteor Showers and their Parent Comets" published by Cambridge University Press
Cambridge University Press
Cambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the world's oldest publishing house, and the second largest university press in the world...

 in 2006. Jenniskens is chair of the Working Group on Meteor Shower Nomenclature of Commission 22 of the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...

 (2006–2012). Discovered at Ondřejov Observatory
Ondrejov Observatory
The Ondřejov Observatory is the principal observatory of the Astronomical Institute of the Academy of Sciences of the Czech Republic. It is located near the village of Ondřejov, 35 km southeast of Prague....

 by Petr Pravec
Petr Pravec
Petr Pravec is a Czech astronomer, born in Třinec, a prolific discoverer of binary asteroids using lightcurve photometric studies. He is leading the effort of a large consortium of stations called BinAst to look for multiplicity in the NEA and inner main-belt populations...

, asteroid "42981 Jenniskens
42981 Jenniskens
42981 Jenniskens is a main belt asteroid with an orbital period of 1475.3877052 days . The asteroid was discovered on October 2, 1999 at Ondrejov Observatory, Czech Republic, by Petr Pravec. Originally designated "1999 TY224", the asteroid was subsequently named after astronomer Peter Jenniskens,...

" is named in his honor.

In 2008, Jenniskens together with Muawia Shaddad, lead a team from the University of Khartoum
University of Khartoum
The University of Khartoum ia a multi-campus, co-educational university located in Khartoum. It is the largest and oldest university in Sudan. UofK was founded as Gordon Memorial College in 1902 and established in 1956 when Sudan gained independence...

 in Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...

 that recovered fragments of asteroid 2008 TC3
2008 TC3
thumb|right|300px|Ground path of the meteoroid; red line is the path, terminating where it would have hit the ground; green line is the infrasound detection of the explosion; orange crosshairs show METEOSAT IR fireball location; predicted altitudes are listed; exact path and fireball altitude not...

 in the Nubian Desert
Nubian Desert
The Nubian Desert is in the eastern region of the Sahara Desert, spanning approximately 400,000 km² of northeastern Sudan between the Nile and the Red Sea. The arid region, a largely sandstone plateau, has lots of wadis flowing towards the Nile. There is virtually no rainfall in the Nubian,...

, marking the first time meteorite fragments had been found from an object that was previously tracked in outer space before hitting Earth.

Meteor showers

Jenniskens is the principal investigator of NASA's Leonid Multi-Instrument Aircraft Campaign (Leonid MAC), a series of four airborne missions that fielded modern instrumental techniques to study the 1998 - 2002 Leonids
Leonids
The Leonids is a prolific meteor shower associated with the comet Tempel-Tuttle. The Leonids get their name from the location of their radiant in the constellation Leo: the meteors appear to radiate from that point in the sky. They tend to peak in November.Earth moves through the meteoroid...

 meteor storms. These missions helped develop meteor storm prediction models, detected the signature of organic matter
Organic matter
Organic matter is matter that has come from a once-living organism; is capable of decay, or the product of decay; or is composed of organic compounds...

 in the wake of meteors as a potential precursor to origin-of-life chemistry, and discovered many new aspects of meteor radiation.

More recent meteor shower missions include the Aurigid Multi-Instrument Aircraft Campaign (Aurigid MAC), which studied a rare September 1, 2007, outburst of Aurigids from long-period comet C/1911 N1 (Kiess), and the Quadrantid Multi-Instrument Aircraft Campaign (Quadrantid MAC), which studied the January 3, 2008, Quadrantids
Quadrantids
The Quadrantids are an easily visible January meteor shower.The radiant of this shower is an area inside the constellation Boötes. The name comes from Quadrans Muralis, an obsolete constellation that is now part of Boötes...

.

Jenniskens identified several important mechanisms of how our meteor showers originate. Since 2003, Jenniskens identified the Quadrantids
Quadrantids
The Quadrantids are an easily visible January meteor shower.The radiant of this shower is an area inside the constellation Boötes. The name comes from Quadrans Muralis, an obsolete constellation that is now part of Boötes...

 parent body 2003 EH1, and several others, as new examples of how fragmenting comets are the dominant source of meteor showers. These objects are now recognized as the main source of our zodiacal dust cloud. Before that, he predicted and observed the 1995 Alpha Monocerotids meteor outburst (with members of the Dutch Meteor Society), proving that "stars fell like rain at midnight" because the dust trails of long-period comets wander on occasion in Earth's path.

Spacecraft reentries

His research also includes artificial meteors. Jenniskens is the principal investigator of NASA's Genesis
Genesis (spacecraft)
The Genesis spacecraft was a NASA sample return probe which collected a sample of solar wind and returned it to Earth for analysis. It was the first NASA sample return mission to return material since the Apollo Program, and the first to return material from beyond the orbit of the Moon...

 and Stardust
Stardust (spacecraft)
Stardust is a 300-kilogram robotic space probe launched by NASA on February 7, 1999 to study the asteroid 5535 Annefrank and collect samples from the coma of comet Wild 2. The primary mission was completed January 15, 2006, when the sample return capsule returned to Earth...

 Entry Observing Campaigns to study the fiery return from interplanetary space of the Genesis (Sep. 2004) and Stardust (Jan. 2006) sample return capsules. These airborne missions studied what physical conditions the protective heat shield endured during the reentry before being recovered.

More recently, Jenniskens led a mission to study the destructive entry of ESA's Automated Transfer Vehicle
Automated Transfer Vehicle
The Automated Transfer Vehicle or ATV is an expendable, unmanned resupply spacecraft developed by the European Space Agency . ATVs are designed to supply the International Space Station with propellant, water, air, payload and experiments...

 "Jules Verne" on 29 September 2008 and the beautiful reentry of JAXA's Hayabusa
Hayabusa
was an unmanned spacecraft developed by the Japan Aerospace Exploration Agency to return a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis....

 probe over Australia on 13 June 2010. An overview of ongoing missions can be found at: http://airborne.seti.org.

2008 TC3 fragments recovery

The recovery of fragments of asteroid 2008 TC3
2008 TC3
thumb|right|300px|Ground path of the meteoroid; red line is the path, terminating where it would have hit the ground; green line is the infrasound detection of the explosion; orange crosshairs show METEOSAT IR fireball location; predicted altitudes are listed; exact path and fireball altitude not...

 marked the first time fragments had been found from an object that was previously tracked in outer space before hitting Earth. This search was led by Peter Jenniskens and Muawia Shaddad of the University of Khartoum
University of Khartoum
The University of Khartoum ia a multi-campus, co-educational university located in Khartoum. It is the largest and oldest university in Sudan. UofK was founded as Gordon Memorial College in 1902 and established in 1956 when Sudan gained independence...

 in Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...

, and carried out with help from students and staff of the University of Khartoum. The search of the impact zone began on December 6, 2008 and turned up 24 pounds (10.9 kg) of rocks in about 600 fragments.

Other research

In earlier collaborations, he discovered that an unusual viscous form of liquid water can be a common form of amorphous ice
Amorphous ice
Amorphous ice is an amorphous solid form of water, meaning it consists of water molecules that are randomly arranged like the atoms of common glass. Everyday ice is a crystalline material where the atoms are regularly arranged in a lattice whereas amorphous ice is distinguished by a lack of...

 in comets and icy satellites (during a post-doc study with David F. Blake) and he created the first broad detection-limited survey of Diffuse Interstellar Bands in his PhD thesis work with Xavier Désert.
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