Nav: Home

The threat of Centaurs for the Earth

October 08, 2018

The astrophysicists Mattia Galiazzo and Rudolf Dvorak from the University of Vienna, in collaboration with Elizabeth A. Silber (Brown University, USA) investigated the long-term path development of Centaurs (solar system minor bodies which originally have orbits between Jupiter and Neptune). These researchers have estimated the number of close encounters and impacts with the terrestrial planets after the so-called Late Heavy Bombardment (about 3.8 billion years ago) as well as the possible sizes of craters that can occur after a collision with the Earth (and the other terrestrial planets). The publication was recently published in Monthly Notices of the Royal Astronomical Society.

Centaurs are the solar system objects whose orbits are found between those of the giant planets. They originate mainly from the Trans-Neptunian objects, and are among the sources of Near-Earth Objects. Thus, it is crucial to understand their orbital evolution which in some cases might end in collision with terrestrial planets and produce catastrophic events. The researchers studied the orbital evolution of the Centaurs toward the inner solar system, and estimate the number of close encounters and impacts with the terrestrial planets after the Late Heavy Bombardment (from about 3.8 billion years ago, until now) assuming a steady state population of Centaurs. "We also estimate the possible crater sizes. Centaurs can become also active comets, because of the presence of water on a good number of them, thus we also compute the approximate amount of water released to the Earth, which is comparable to the amount of water present on the Adriatic sea, now. We also found subregions of the Centaurs where the possible impactors originate from", explains Mattia Galiazzo.

While crater sizes could extend up to hundreds of kilometers in diameter given the presently known population of Centaurs the majority of the craters would be less than ~10 km. For all the planets and an average impactor size of ~12 km in diameter, we have on average 2 impacts since the Late Heavy Bombardment for the Earth and between 1 and 2 for Venus. Luckily this "bombardment" is less intense (of at least one tenth) the impacts done by asteroids between Mars and Jupiter. However Centaurs come on average much faster and have larger bodies in general. For smaller Centaurs (e.g. with a diameter, D> 1 km), the impact frequency is way larger, about one every 14 Myr for the Earth, 13 Myr for Venus and, 46 for Mars, in the recent solar system. The researchers find that about half of the Centaurs can enter into the terrestrial planet region and ~7% of them can interact with terrestrial planets. In the case of an impact, Centaurs could be the cause of catastrophic, such as events extinction of life as we presently know it.

These results provide an important contribution in the analysis of catastrophic events of extraterrestrial origin, which might happen not only on our planet, but also on planets like Mars and Venus. "Our work also provides the framework for better understanding past events, and how they might had altered life on Earth and other terrestrial planets", tells Galiazzo. For example, Dvorak says: "Such events could have a direct impact of life by either destroying it (e.g. Earth) or creating conducive conditions (e.g. hydrotermal activity) for new life to form. In addition, our results give more answers on the evolution of the present solar system".

Another interesting fact, Silber asserts: "Centaurs can bring water to Mars after a collision" and recent missions confirm the presence of water on Mars.
Publication in Monthly Notices of the Royal Astronomical Society

M A Galiazzo, E A Silber, R Dvorak: The threat of Centaurs for terrestrial planets and their orbital evolution as impactors. Monthly Notices of the Royal Astronomical Society

University of Vienna

Related Mars Articles:

The seismicity of Mars
Fifteen months after the successful landing of the NASA InSight mission on Mars, first scientific analyses of ETH Zurich researchers and their partners reveal that the planet is seismically active.
Journey to the center of Mars
While InSight's seismometer has been patiently waiting for the next big marsquake to illuminate its interior and define its crust-mantle-core structure, two scientists, have built a new compositional model for Mars.
Getting mac and cheese to Mars
Washington State University scientists have developed a way to triple the shelf life of ready-to-eat macaroni and cheese, a development that could have benefits for everything from space travel to military use.
A material way to make Mars habitable
New research suggest that regions of the Martian surface could be made habitable with a material -- silica aerogel -- that mimics Earth's atmospheric greenhouse effect.
Life on Mars?
Researchers from Hungary have discovered embedded organic material in a Martian meteorite found in the late 1970s.
New evidence of deep groundwater on Mars
Researchers at the USC Arid Climate and Water Research Center (AWARE) have published a study that suggests deep groundwater could still be active on Mars and could originate surface streams in some near-equatorial areas on Mars.
Why we won't get to Mars without teamwork
If humanity hopes to make it to Mars anytime soon, we need to understand not just technology, but the psychological dynamic of a small group of astronauts trapped in a confined space for months with no escape, according to a paper published in American Psychologist, the flagship journal of the American Psychological Association.
Mars: Not as dry as it seems
Two new Oxford University papers have shed light on why there is no life on Mars.
More evidence of water on Mars
River deposits exist across the surface of Mars and record a surface environment from over 3.5 billion years ago that was able to support liquid water at the surface.
How hard did it rain on Mars?
Heavy rain on Mars reshaped the planet's impact craters and carved out river-like channels in its surface billions of years ago, according to a new study published in Icarus.
More Mars News and Mars Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 3: Shared Immunity
More than a million people have caught Covid-19, and tens of thousands have died. But thousands more have survived and recovered. A week or so ago (aka, what feels like ten years in corona time) producer Molly Webster learned that many of those survivors possess a kind of superpower: antibodies trained to fight the virus. Not only that, they might be able to pass this power on to the people who are sick with corona, and still in the fight. Today we have the story of an experimental treatment that's popping up all over the country: convalescent plasma transfusion, a century-old procedure that some say may become one of our best weapons against this devastating, new disease.   If you have recovered from Covid-19 and want to donate plasma, national and local donation registries are gearing up to collect blood.  To sign up with the American Red Cross, a national organization that works in local communities, head here.  To find out more about the The National COVID-19 Convalescent Plasma Project, which we spoke about in our episode, including information on clinical trials or plasma donation projects in your community, go here.  And if you are in the greater New York City area, and want to donate convalescent plasma, head over to the New York Blood Center to sign up. Or, register with specific NYC hospitals here.   If you are sick with Covid-19, and are interested in participating in a clinical trial, or are looking for a plasma donor match, check in with your local hospital, university, or blood center for more; you can also find more information on trials at The National COVID-19 Convalescent Plasma Project. And lastly, Tatiana Prowell's tweet that tipped us off is here. This episode was reported by Molly Webster and produced by Pat Walters. Special thanks to Drs. Evan Bloch and Tim Byun, as well as the Albert Einstein College of Medicine.  Support Radiolab today at