NEO Coordination Centre


Precursor services

Current number of known NEAs:
Current number of NEAs in risk list:
Last update: 2019-05-18 14:39:00 UTC


First ground-based observation of (66391) 1999 KW4 during the current apparition

14 May 2019

Asteroid (66391) 1999 KW4, the target of an ongoing IAWN observing campaign, has been observed from the ground for the first time in the current apparition, emerging from solar conjunction.

The observation has been achieved thanks to a newly established collaboration between ESA and the Observatoire des Makes, in the French island of La Réunion, in the Indian Ocean. The southern location of the telescope favoured the observability of the object while it was still close to the Sun.

Over the upcoming weeks, the object will get progressively brighter, on its way to a close approach with Earth on 25 May, when it is expected to reach magnitude 12.5. During this time, dozens of telescopes collaborating with IAWN will try to collect as many observations as possible, with as many observing techniques and wavelengths as possible. The goal is to put observatories and telescopes to the test, to become aware of what kind of information can be collected on short notice in case of a future close approach of a possibly threatening asteroid. At the same time, thanks to the fact that (66391) 1999 KW4 is a binary object, its analysis will also work as a test case for a similar investigation on (65803) Didymos, the designated target of the DART and Hera missions.

The animation presented here is composed of two 90 s exposures, obtained on 2019 May 09.07 UT with the 0.6 m telescope at the Observatoire des Makes. At the moment of the observation, the object had an altitude of ~20° above the horizon, and an elongation of just 50° from the Sun.

[Credit: Frédéric Vachier, Jerome Berthier (Observatoire de Paris Meudon, CNRS), Marco Micheli, Rüdiger Jehn (ESA NEOCC), A. Klotz (IRAP), J.-P. Teng, A. Peyrot, P. Thierry (Observatoire des Makes, La Réunion)]



ESA’s Planetary Defence Office actively participates at PDC 2019 in the Washington area

10 May 2019

ESA’s Planetary Defence Office (PDO) has participated with several presentations at the 6th IAA Planetary Defense Conference held in College Park, near Washington, between 29 April and 3 May.

The first PDO presentation at the conference was provided by ESA’s Planetary Defence Officer, Rüdiger Jehn, giving an overview of the Planetary Defence activities at ESA. He spoke of the three main PDO pillars at ESA: a) the observations pillar, with the Flyeye telescope as our future workhorse, b) the information provision pillar, with the NEOCC system as its core, and c) the mitigation pillar, with the Hera mission as the most prominent activity. You can see the actual presentation in the following link.

Secondly, the responsible of the NEO Coordination Centre Information System, Juan L. Cano, provided a talk about the recent evolutions in the NEOCC System. The most important additions to it have been the incorporation of the Orbit Determination System and the Impact Monitoring System, both migrated from NEODyS.

Later, NEOCC’s astronomer, Marco Micheli, presented a summary of the observational activities carried out at the NEOCC. Among the multiple collaborations of our team, he spoke of the routine use of the Optical Ground Station (OGS) telescope in Tenerife and the fruitful collaboration with ESO’s Very Large Telescope (VLT), located in Chile, to perform follow-up of interesting NEAs.

Lastly, PDO’s Segment Co-manager, Detlef Koschny, provided a talk on Tuesday about the possibility to launch a cubesat mission to asteroid Apophis based on the M-ARGO concept. Apophis will have a very close approach to Earth in April 2029 and this will represent a fantastic opportunity to fly a mission to this NEA.

ESA’s representatives also participated very actively in the discussions associated to the simulated impact scenario and proposed a number of solutions that were discussed and agreed by the different working groups.

Participation on social media was very significant, especially on Twitter through ESA Operations account, and through two Facebook Live discussions, one done by Rüdiger Jehn and another one participated by Kelly Fast (NASA), Romana Kofler (UNOOSA) and Juan L. Cano (ESA).

In summary, the presence of ESA at the PDC this year has been of remarkable importance. The meeting has also allowed increasing the level of communication within the planetary defence community and fostering related initiatives as the one associated to the Hera mission. Statements of support were agreed and released for the Hera mission, the NEOCam mission and the Apophis 2029 opportunity.




NEOCC Newsletter: May 2019

03 May 2019

The ESA SSA-NEO Coordination Centre has released the May 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.

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




The largest optical telescope started observing very faint NEOs in the Northern hemisphere

2 May 2019

A newly-established collaboration between our team and the Instituto de Astrofísica de Canarias (IAC) led to the first-ever observation of an NEA with the 10.4 m Gran Telescopio Canarias (GTC). We targeted 2019 DS1, a high-rated NEO in our risk list, when it was already as faint as magnitude 25.7.

The object was successfully detected, and the resulting astrometry led to an increase of the object's impact probability, that is now approaching 1 in 800 for an impact in 2082.

For more information you can read the IAC press release at


Close Approach Fact Sheet


NEOCC Close Approach Fact Sheet: 2018 WV1

30 November 2018

The ESA SSA-NEO Coordination Centre has released a Close Approach Fact Sheet (CAFS) for asteroid 2018 WV1, passing by Earth on 02 December. 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