NEO Coordination Centre


Precursor services


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Current number of NEAs in risk list:
Last update: 2020-11-24 07:44:01 UTC


Record breaking close approach of asteroid 2020 VT4

23 November 2020

2020 VT4 observed with ESA's OGS telescope in the evening of 16 November 2020, three days after the closest approach, when it was already 2.2 million kilometres away from our planet. At the time of the observation the small ~10-metre object was already as faint as a magnitude 21 star.   Credit: ESA / NEOCC

On 14 November 2020 the NASA-funded ATLAS survey telescope on Mauna Loa, in Hawaii, detected a new magnitude 18 object, and immediately followed it up. After an observed arc of about 2 hours, it became evident that the new object was a small asteroid quickly receding from Earth, and it had come pretty close to our planet the previous day. But how close? With this initial arc, the answer was still too uncertain, but it was roughly in the thousands of kilometres, if not less. A remarkably close miss.

Fortunately, radially receding objects tend to be easy to follow-up, because their positional uncertainty does not grow too quickly with time. And in fact, just a couple of hours later the Glenlee Observatory in Australia obtained some additional observations, and with them it became evident that the approach had been even closer. This small ~10 metre asteroid had just flown over the South Pacific Ocean at a distance of less than 400 km from the surface of the ocean, by far the closest non-impacting asteroid ever observed while in space.

Over the next few days, other observatories obtained astrometric data, including our own team with ESA's OGS telescope in Tenerife, and we now know the fly-by circumstances extremely well. The closest approach happened over a pretty isolated spot of ocean a few hundred kilometres East of French Polynesia. The lowest altitude reached was 370 km, with a precision of a couple of kilometres, and we can determine the exact time of closest approach to better than a minute.

The object has now been permanently designated 2020 VT4, and it will probably hold the record of the closest non-impacting asteroid for a long time, given the extremely narrow miss at this passage near our planet.



Impact Monitoring information now computed by NEOCC

20 November 2020

Since the first release of ESA's NEO Coordination Centre web portal in 2012 we have been providing accurate estimates of the trajectories of near-Earth asteroids and the threat that they pose to Earth through the computations performed by the University of Pisa's NEODyS system. At that time, ESA had reached an agreement with that university and its spin-off company SpaceDyS to federate their orbit determination and impact monitoring services within ESA's newly created NEO segment web portal. Since then, ESA has been providing the results from NEODyS computations in the NEOCC web portal.

In the last years, ESA has awarded dedicated contracts to SpaceDyS to perform the improvement and migration of the NEODyS software to ESA. Whereas the orbit determination part of this suite was already migrated and put in operations in the first quarter of 2019, the remaining impact monitoring part has only been recently migrated. Consequently, and since today, data presented in our portal are the result of the full orbit determination and impact monitoring computations being performed at our premises and with the so called AstOD software, i.e. an improved version of the original software.

As a consequence of the software upgrade and improvements, the results provided in our portal might be slightly different compared to the ones provided by NEODyS. This is due, mainly, to: the fully new orbit propagator, which is the core of the software, the improved differential corrector, the advanced computation of the score value, which possibly triggers the impact monitoring computation of a given NEA, and the possibility to increase the number of sampling points in the line of variations (see this reference). Moreover, different results have to be expected for impact probabilities below the completeness limit (see this other reference). You can consult our risk list here.

We are grateful to the work done by NEODyS and SpaceDyS scientists and particularly to the vision and outstanding contribution of Prof. Andrea Milani and Dr. Giovanni Valsecchi that have allowed reaching the present outcome.



NEOCC Newsletter: November 2020

05 November 2020

The ESA S2P-NEO Coordination Centre has released the November newsletter summarising the most relevant data and events on asteroids and comets approaching the orbit of the Earth. Please, feel free to forward it to potentially interested people.

We are releasing our sixth PDO riddle with this newsletter and with a deadline on 25 November. Find the release information here:

You can download the newsletter by clicking on the button below; to subscribe to the service, please fill in the form on page




NEOCC Close Approach Fact Sheet: 2020 SW

22 September 2020

The ESA S2P-NEO Coordination Centre has released a Close Approach Fact Sheet (CAFS) for asteroid 2020 SW, passing by Earth on 24 September. Please, feel free to forward it to potentially interested people.

You can download the CAFS by clicking on the button below; for subscribing to our releases, please fill in the form on page