Each year, astronomers worldwide discover over 1000 new asteroids or other space rocks that could strike our planet. And if one is spotted heading towards Earth, experts working in ESA and national emergency offices need to know who should do what, and when.

NELIOTA is an activity initiated by the European Space Agency (ESA), which was recently launched at the National Observatory of Athens. The project aims to count and characterise the number and distribution of near-earth objects (NEOs). NEOs are meteoroids, comets or asteroids found in the neighbourhood of the Earth.

ESA will host the International Academy of Astronautic's 4th Planetary Defence Conference (PDC 2015), entitled ‘Assessing Impact Risk & Managing Response', at the Agency's ESRIN establishment, near Rome, 13–17 April 2015. A media briefing will be held on 16 April 2015.

If an asteroid were spotted headed towards Earth, what could humanity do about it? ESA's latest mission is part of a larger international effort to find out. This month marked the start of preliminary design work on ESA's Asteroid Impact Mission, or AIM. Intended to demonstrate technologies for future deep-space missions, AIM will also be the Agency's very first investigation of planetary defence techniques.

ESA and national disaster response offices recently rehearsed how to react if a threatening space rock is ever discovered to be on a collision course with Earth. Last month, experts from ESA's Space Situational Awareness (SSA) programme and Europe's national disaster response organisations met for a two-day exercise on what to do if an asteroid is ever found to be heading our way.  

On 18th November, ESRIN and the heart of ESA's NEO activities, the NEO Coordination Centre (NEOCC), welcomed an elaborate group of people involved in NEO activities in Europe. About 40 NEO scientists, technical, and political experts followed the final presentations and status reports of four activities carried out for ESA over the last two years.

The recent claim that asteroid 2014 UR116 may be threatening the Earth shows how difficult it is to convey the right message about the NEO hazard. The no-news spread after statements from the discoverers: the asteroid was no imminent threat but if, in a not yet foreseeable distant future, it hit the Earth then due to its large size (400 m) the effects would be devastating.

The Large Binocular Telescope (LBT), of which the Italian National Institute for Astrophysics (INAF)  is a main partner, has successfully observed asteroid 2014 KC46 in one of the faintest Near-Earth Object (NEO) recoveries ever performed. This challenging observation, which pushed the limits of the telescope down to a visual magnitude of 26.3, was carried out on the nights of 28 and 30 October 2014 by a new collaboration between the Italian LBT team and the NEO Coordination Centre of the European Space Agency.

The ESA Optical Ground Station has quickly become a major asset for the NEO Coordination Centre, thanks to the many nights devoted to observing asteroids. It is located at an altitude of 2400 m on the slope of a volcano, in Tenerife, hosted at the Observatorio del Teide - Instituto the Astrofisica de Canarias.

After discussing what to do to ensure that an important NEO is adequately monitored (see "news archive"), we will now present a possible strategy to improve the orbit of old objects, that have not been properly observed in the past.

Spotting Earth-threatening asteroids is tough partly because the sky is so big. But insects offer an answer, since they figured out long ago how to look in many directions at once.

The observational component of NEO science is an extremely important part of the impact mitigation effort, since observations are the input data for all the computational models used to predict future collisions. This post will summarize our effort to ensure that enough data are obtained, especially on the most important and challenging objects, during the short time when they are observable.

In the evening of 07 September 2014, the newly discovered asteroid 2014 RC will have a very close fly-by of just above 30000 km to our planet. The object is estimated to be between 10 and 30 m in size. While the fly-by is very close, there is no chance that the object will hit the Earth.

Today the NEO Coordination Centre (NEOCC) celebrates its first year of activities. On 22 May 2013 the Centre was formally inaugurated at ESRIN by Thomas Reiter, ESA Director of Human Spaceflight and Operations. Since then, the Centre has regularly provided information and data on NEOs through its main services updated on a daily basis (Risk list, Priority list, Close Approaches and Physical Properties) and through its technical news service.

A team of European astronomers has found a previously unknown comet, detected as a tiny blob of light orbiting our Sun deep in the Solar System.

With a mandate from the UN, ESA and other space agencies from around the world are about to establish a high-level group to help coordinate global response should a threatening asteroid ever be found heading towards Earth.

The first recovery campaign carried out by the ESA NEO Coordination Centre in coordination with ESO, using the Very Large Telescope (VLT) (VLT telescopes on the Paranal mountain in Chile (credit: ESO)) turned out to be a success. Before the campaign, asteroid 2009 FD was ranked among the top five objects in the risk list.

In a fruitful collaboration between ESA and a group of amateur astronomers, the first comet was discovered by the so-called TOTAS survey. The comet is called P/2014 C1 (TOTAS) and has an orbit between Jupiter and Mars. TOTAS stands for 'Tenerife Observatory Teide Asteroid Survey'.

If an asteroid is discovered which could come very close to Earth, it is important to coordinate observational activities quickly to better know its precise flyby distance.This is illustrated by the following case of near-Earth asteroid (NEA) 2013 NJ.

On 8 November 2013 asteroid 2013 TV135 has been removed from the Risk Page. The non-zero impact probability spotted by monitoring systems just after its discovery (on 8 October 2013) dropped essentially to zero. The bulk of astrometric data collected by astronomers during exactly one month of observations helped to improve our knowledge of its orbit, that eventually turned out to be a safe one.