Astronomers identify oldest known asteroid family

Southwest Research Institute (SwRI) was part of an international team that recently discovered a relatively unpopulated region of the main asteroid belt, where the few asteroids present are likely pristine relics from early in solar system history. The team used a new search technique that also identified the oldest known asteroid family, which extends throughout the inner region of the main asteroid belt.

The main belt contains vast numbers of irregularly shaped asteroids, also known as planetesimals, orbiting the Sun between Mars and Jupiter. As improved telescope technology finds smaller and more distant asteroids, astronomers have identified clusters of similar-looking bodies clumped in analogous orbits. These familial objects are likely fragments of catastrophic collisions between larger asteroids eons ago. Finding and studying asteroid families allows scientists to better understand the history of main belt asteroids.

oldest asteroid family

An artist’s impression of an asteroid breaking up. Credit: NASA/JPL-Caltech

“By identifying all the families in the main belt, we can figure out which asteroids have been formed by collisions and which might be some of the original members of the asteroid belt,” said SwRI Astronomer Dr. Kevin Walsh, a coauthor of the online Science paper detailing the findings. “We identified all known families and their members and discovered a gigantic void in the main belt, populated by only a handful of asteroids. These relics must be part of the original asteroid belt. That is the real prize, to know what the main belt looked like just after it formed.”

Identifying the very oldest asteroid families, those billions of years old, is challenging, because over time, a family spreads out. As asteroids rotate in orbit around the Sun, their surfaces heat up during the day and cool down at night. This creates radiation that can act as a sort of mini-thruster, causing asteroids to drift widely over time. After billions of years, family members would be almost impossible to identify, until now. The team used a novel technique, searching asteroid data from the inner region of the belt for old, dispersed families. They looked for the “edges” of families, those fragments that have drifted the furthest.

“Each family member drifts away from the center of the family in a way that depends on its size, with small guys drifting faster and further than the larger guys,” said team leader Marco Delbo, an astronomer from the Observatory of Cote d’Azur in Nice, France. “If you look for correlations of size and distance, you can see the shapes of old families.”

“The family we identified has no name, because it is not clear which asteroid is the parent,” Walsh said. “This family is so old that it appears to have formed over 4 billion years ago, before the gas giants in the outer solar system moved into their current orbits. The giant planet migration shook up the asteroid belt, removing many bodies, possibly including the parent of this family.”

The team plans to apply this new technique to the entire asteroid belt to reveal more about the history of the solar system by identifying the primordial asteroids versus fragments of collisions. This research was supported by the French National Program of Planetology and the National Science Foundation. The resulting paper, “Identification of a primordial asteroid family constrains the original planetesimal population,” appears in the August 3, 2017, online edition of Science.

 

Original article here.

NEOShield-2 Agent Germany Activities

By Frank Koch, NEOShield-2 Agent in Germany

In July 2017 Frank Koch held several events in front of different audiences about the threat of Near-Earth-Objects (NEOs) and potential counter fights studied within the NEOShield-2 project.

The main event was a session within the space camp in Berlin organized by FEZ Berlin. During one week, young people from all over Germany studied different space topics, had practical experiences and lessons from astronauts and experts about space relevant topics. On the last day, Frank Koch, physician and asteroid enthusiast, gave his NEOShield-2 lecture.

NEOShield-2 Agent Germany Frank Koch

Frank Koch giving his lecture

Starting with a short overview how the solar system was formed, the discussion went quickly to the fact that there is much more than just nine planets within our solar system like asteroids. The young experts were extremely curious to learn more about asteroids, their classifications and estimated numbers. Lots of questions have been asked and answered and together several mitigation possibilities have been explored.

Overall the NEOShield-2 activities haven been well received and some pupils expressed their interests in space engineering and physics for their choice of studies in the future.

NEOShield-2 Agent Germany Frank Koch

Space camp lecture room with lots of space objects and models

The lively discussion continued over lunch and overall the topic was extremely well received by the audience of 35+ people and will be repeated for sure at the next space camp.

Besides this event, 3 more sessions were delivered for smaller audiences (adults) during July twice in Berlin and one time in Munich, so overall roughly 70 people were reached.

 

NEOShield-2 Note:

The NEOShield-2 team is very proud of our new agent Frank Koch and all his effort to help us to educate people about asteroids, the threat they may pose to us and how the project is working to save our planet.

NEOShield-2 Agent Denmark – Asteroid Day 2017

Overview of this year’s Asteroid Day Events in Denmark, supported by the NEOShield-2 project

Written by Jordi S. Forteza, NEOShield-2 outreach agent. Reviewed by Dr. Morten Bo Madsen (Niels Bohr Institute) & Dr. Line Drube (NEOShield-2 & German Aerospace Center – DLR) & Tina Ibsen (Head of Science & Outreach, Tycho Brahe Planetarium).

Special thanks to SNU (“Selskabet for Naturlærens Udbredelse”), the Danish Association for the Advancement of Natural Sciences, founded by H.C. Ørsted in 1824. Their kind help, advertising efforts, arrangement of the venue, caretaking of the guests & settlement of the lectures, were key factors for the good course of the lectures, as well as the meteorite exhibition at the Geology Museum.

This year’s events about asteroid science & the threat imposed by them, were held in two different locations in Copenhagen, the capital of Denmark, doubling the number of events from last year.

The first event was a warm-up for Asteroid Day, as because it was held on the 2nd of March. It was an hour long talk about “Asteroids, impact threat & the potential applications of Asteroids”. This talk was given by amateur astronomer Jordi S. Forteza, and was held at the Round Tower (“Runde Tårn”) in Copenhagen. The materials used for this talk were developed by some professionals from the Space sector such as, the NEOShield-2 project & the Space Resources Initiative, as well as by Eric J. Christensen, Director of the Catalina Sky Survey (University of Arizona). The Round Tower reflects a lot of astronomical history in Denmark, and it has the oldest working observatory in Europe at its roof as well. The event was organised by KAF (“Københavns Astronomiske Forening”), The Astronomical Association of Copenhagen. It was a closed event for its members only. Unfortunately, no pictures were taken or video was recorded. Despite of that, it was a good event, where 17 people attended and many interesting questions were addressed.

The second event this year was held at the Geology Museum of Copenhagen. This museum is part of the Natural History Museum of Denmark, and it is owned by the University of Copenhagen. This event also took place on June 30th, and was organised by SNU (“Selskabet for Naturlærens Udbredelse”), the Danish Association for the Advancement of Natural Sciences. The instigators of this event where the danish planetary scientist Dr. Line Drube (NEOShield-2, German Aerospace Center – DLR) & amateur astronomer Jordi S. Forteza (NEOShield-2 outreach agent). This event was a good ending for this year’s events, both by means of number of participants and by means of apparent satisfaction from an audience of 100 attendees.

The audience was composed by citizens of Copenhagen, university students, as well as by danish scientists and engineers from the Space sector.

NEOShield-2 Agent Denmark Asteroid Day 2017

The audience of 100 interested and inquisitive minds.

NEOShield-2 Agent Denmark Asteroid Day 2017

Dr. Morten Bo Madsen from the Niels Bohr Institute capturing the attention of the audiences, while explaining interesting facts about the World’s largest iron meteorite slice.

NEOShield-2 Agent Denmark Asteroid Day 2017

Dr. Line Drube from DLR to the left, Dr. Morten Bo Madsen from the Niels Bohr Institute in the middle and Jordi Forteza from Asteroid Day Denmark to the right, after an evening of lectures and guided tours.

Talks of 2017

Introduction to the International Asteroid Day. – Jordi S. Forteza, regional coordinator for Asteroid Day Denmark.

NEOShield-2 Agent Denmark Asteroid Day 2017

Jordi Forteza from Asteroid Day Denmark talking about his work as an amateur astronomer, during his introduction to and explanation of the International Asteroid Day.

New Giant Impact Crater found in Northern Greenland. – Dr. Kurt H. Kjær, professor & Director af Science at The Natural History Museum of Denmark.

NEOShield-2 Agent Denmark Asteroid Day 2017

Dr. Kurt Kjær from the National History Museum of Denmark, during his talk about a possible giant crater found in Northern Greenland.

Kurt Kjær presented the results from his intensive study of a possible giant crater found in Northern Greenland. His study is currently under peer-review for a major scientific journal, so no further information about this interesting work can be published at the moment.

What are asteroids & how can we defend ourselves against them? Dr. Line Drube, Planetary Scientist from the NEOShield-2 project, German Aerospace Center – DLR.

NEOShield-2 Agent Denmark Asteroid Day 2017

Dr. Line Drube from DLR, during her talk about asteroids and how space missions can deflect asteroids on collision course with Earth.

Line Drube presented interesting facts about the ways humankind can defend itself from asteroid impacts of different types, as well as about the physics involved in a possible asteroid deflection mission. Line is also a member of the United Nations Space Mission Advisory Group, and she talked about her work as a scientist with space/international lawyers in regard to the legal issues with planetary defence missions.

All in all, we are very proud and happy to see that all events were well received by the public, and that the interest was apparently high every time! Two talks from the last event were video-recorded. The one from Jordi and the other one from Line are now available on the “Dansk Videnskab” channel on YouTube [danish only].

Fun fact

This year’s Asteroid Day event at the Geology Museum, would probably never have happened without an asteroid naming attempt, that was cancelled!

It was late March 2017 and Jordi Forteza was thinking about naming an asteroid. The asteroid in question was one, that he helped discover during the time when he was a very active amateur astronomer, back in Mallorca in 2003. After some time thinking about it, he finally decided the naming should honour the Danish asteroid scientist Dr. Line Drube, hoping that it might also attract attention towards Asteroid Day in Denmark. After starting the naming process he however received a message from a senior scientist at the Planetary Research Institute at DLR, who kindly asked Jordi to withdraw the proposal, as he and some colleagues wanted to be the ones to surprise her with an asteroid, and they had already also started the naming process. In May 2017 the 3 km large asteroid (11262 Drube) was announced, and Line learned that not only one group, but two had been in the process of trying to name an asteroid for her. She felt lucky and flattered to hear it, and decided to thank Jordi for his attempt by offering to organize an Asteroid Day event with him this year and using her network to do it. So almost all what you have just read, was the result of this “failed” naming attempt.

Have a great day…
…and fly safe as crew-members of spaceship Earth!

Kind regards,

Jordi S. Forteza
NEOShield-2 Agent and Asteroid Day Denmark

 

NEOShield-2 Agent on Board the Queen Mary 2 Cruise Ship

By John Maclean FRAS – NEOShield-2 Agent in the United Kingdom, Exeter Observatory

At the beginning of the year I undertook a lecturing trip on the Queen Mary 2 ocean liner, visiting Australia, Borneo, Vietnam and China. In my role as a Royal Astronomical Society (RAS) speaker, I delivered a series of talks to the guests on the ship.

NEOShield-2 agent John Maclean Queen Mary 2

The Queen Mary 2 is the only ship at sea with a Planetarium and the RAS has an agreement with the ships’ operator, Cunard, to provide Fellows to deliver the Astronomy programme on board. One of the talks I gave was entitled, “OMG, We’re all going to die!” which aims to educate and inform the audience about the dangers posed by Potentially Hazardous Asteroids (PHA’s).

NEOShield-2 agent John Maclean Queen Mary 2

During the talk I introduced the audience to the NEOShield-2 project and explained the project aims, activities and achievements to date. The talk was very well received, with over 400 people attending and many questions were asked about the NEOShield-2 project, which I was happy to answer. I look forward to further promoting the mission to more audiences in the near future.

 

NEOShield-2 note:

The project’s team is very happy to have John as agent and appreciate all his effort to help us to raise public awareness about the threat posed by asteroids and what our project is doing to save our planet. We are looking forward to his next events!