More than 15,000 near-Earth objects and counting

More than 15,000 near-Earth objects and counting
Final sequence of images of Asteroid Lutetia, acquired on 10 July 2010 by ESA’s Rosetta spacecraft just before making closest approach of 3162 km. Lutetia is an elongated body, with its longest side around 130 km. Credit:   ESA 2010 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

The international effort to find, confirm and catalogue the multitude of asteroids that pose a threat to our planet has reached a milestone: 15 000 discovered – with many more to go.

The number of catalogued asteroids approaching Earth has grown rapidly since the count reached 10 000 only three years ago.

Near-Earth objects, or NEOs, are asteroids or comets with sizes ranging from metres to tens of kilometres whose orbits come close to ours, meaning they could hit our planet.

The discovered NEOs are part of a much larger population of more than 700 000 known asteroids in our Solar System.

"The rate of discovery has been high in the past few years, and teams worldwide have been discovering on average 30 new ones per week," says Ettore Perozzi, manager of the NEO Coordination Centre at ESA's centre near Rome, Italy.

"A few decades back, 30 were found in a typical year, so international efforts are starting to pay off. We believe that 90% of objects larger than 1000 m have been discovered, but – even with the recent – we've only found just 10% of the 100 m NEOs and less than 1% of the 40 m ones."

Today, the two main discovery efforts are in the US: the Catalina Sky Survey in Arizona, and the Pan-STARRS project in Hawaii, jointly accounting for about 90% of the new bodies found.

More than 15,000 near-Earth objects and counting
An object entered the atmosphere over the Urals early in the morning of 15 February 2013. The fireball exploded above Chelyabinsk city, and the resulting overpressure caused damage to buildings and injuries to hundreds of people. This photo was taken by Alex Alishevskikh from about a minute after noticing the blast. Credit: Alex Alishevskikh CC BY-SA 2.0 via http://www.flickr.com/photos/alexeya/

ESA is contributing through its Space Situational Awareness programme, setting up the centre in Italy to combine new and existing European telescope data and support a new network to distribute information.

Maintaining the European risk list

"The centre maintains the European Risk List, containing all objects for which an Earth-impact probability cannot yet be ruled out, however low," says Detlef Koschny, heading the NEO element of the Space Situational Awareness office.

"There is only a tiny impact probability for any known object in the next 40 years, but all NEOs bear close watching to refine and understand their orbits."

The coordination centre is also the focal point for scientific studies needed to improve warning services and provide near-realtime data to scientific bodies, international organisations and government decision-makers.

In recent years, astronomers working with or sponsored by ESA have concentrated on follow-up observations, confirming new objects and obtaining more reliable orbits. Some of this work was done with ESA's own observatory on Tenerife in the Canary Islands.

More than 15,000 near-Earth objects and counting
Fly-eye telescope. Credit: ESA/A. Baker

Others have been instrumental in imaging or confirming the orbits of particularly interesting objects, such as 2016 RB1, which grazed our planet on 7 September 2016 by 34 000 km, within the orbit of many telecom satellites.

In the coming years, the pace of discovery is likely to increase.

ESA is developing new 'fly eye' telescopes to conduct automated nightly wide-sky surveys with their very large fields of view. These are expected to begin operating around 2018. The Large Synoptic Survey Telescope, being built in Chile, is set to begin hunting space rocks in the near future.

These future telescopes offer the almost complete sky coverage and depth needed for humanity to be sure that as many NEOs as possible are discovered and identified before posing any threat.


Explore further

Small asteroid flies safely past Earth

Citation: More than 15,000 near-Earth objects and counting (2016, October 28) retrieved 21 August 2019 from https://phys.org/news/2016-10-near-earth.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
225 shares

Feedback to editors

User comments

Oct 28, 2016
This alone is reason enough to establish independent colonies elsewhere in the system ASAP.

We may very well be the only intelligent species ever to emerge. We ought to be acting like it at any rate.

Oct 28, 2016
Hopefully we are safe until 2018. I could only imagine the confusion if a bomb hit and war started. Half the people wouldn't know if it was a bomb or a meteoroid.

Oct 29, 2016
You won't get off this planet in any meaningful way, unless the Project Orion spaceship project is restarted. The current and proposed propulsion systems do not have the power to accomplish even a manned Mars mission, Project Orion can lift 10,000 TONS in one go enough to transport people and build a colony on Mars. If the Americans don't shrug off the political issues and do it, the Chinese or Russians will, eventually.

Oct 29, 2016
You won't get off this planet in any meaningful way, unless the Project Orion spaceship project is restarted
You fail to appreciate the potential growth rate of the tropical human animal.
If we move to another planet we will be further away from near Earth objects.
It does not take rocket science however to see that that such a move would not solve the problem
What problem are you referring to? It only takes a little math to realize that 1 independent colony = 1/2 the possibility of extinction.

Oct 30, 2016
This alone is reason enough to establish independent colonies elsewhere in the system ASAP.

We may very well be the only intelligent species ever to emerge. We ought to be acting like it at any rate.


Or just develop an effective global defense system rather than wasting our (humanity's) time with trivial wars.

Oct 31, 2016
It's the debris from the creation of the Grand Canyon.

Oct 31, 2016
About 99% into the current age of planet earth, a complex asteroid grouping was catastrophic, it really would mean current worries are irrelevant. Imagine something similar at 100% of current age. Woops, that is now.

Oct 31, 2016
I guess what I mean is Chuxlub is so far inside all current standard polling deviations that Chuxlub is right now. Of course we would see it coming, but obviously no mega movie construct will deflect, just the reality. Just because we observe and talk and design right now, is no help for the future. This planet is it, everyone knows this. Elon and Richard and all the cool dudes will die like the rest of us. Sad but true.
Mars is a wasteland, did I really just say that?
Does anyone believe anything else? I go to the sea shore and watch the waves roll in and the gannet colony breed and breed and breed year after year.
Mars? I think that is for someone with more time than I have.

Oct 31, 2016
I could only imagine the confusion if a bomb hit and war started

The magnitude and/or lack of radiation would be a bit of a giveaway,

Or just develop an effective global defense system rather than wasting our (humanity's) time with trivial wars.

But, but, but...wars make profits...which buy bikini models for threesomes. Have some sense for priorities, man.

Oct 31, 2016
The magnitude and/or lack of radiation would be a bit of a giveaway
Entirely relative.

"U.S. early warning satellites detected an explosion in the Earth's atmosphere June 6, at the height of the tension, with an energy release estimated to be 12 kilotons.

"Had the bright flash, accompanied by a damaging shock wave, occurred over India or Pakistan, the resulting panic could have sparked a nuclear war, Worden recently told members of the congressionally mandated Commission on the Future of the US Aerospace Industry in testimony here.

"Although U.S. officials quickly determined that a meteor caused the explosion, neither India nor Pakistan have the sophisticated sensors that can determine the difference between a natural near-Earth object impact and a nuclear detonation, Worden said in written testimony."
But, but, but...wars make profits...which buy bikini models for threesomes. Have some sense for priorities, man
Plus theyre entirely inevitable, man.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more