The fly-by of 2020 HS7 asteroid

Close Approach Fact Sheet for asteroid (52768) 1998 OR2

NEO Coordination Centre's observing campaign to track the fly-by of BepiColombo

ESA's NELIOTA project detects the flash of light produced when an asteroid collides energetically with the lunar surface and recently recorded its 100th impact.

Planetary Defence office we took the opportunity of the Solar Orbiter launch to perform an observational exercise, attempting to image the departing spacecraft with a ground based optical telescope.

The year has just started, and we already have a very interesting discovery of a new and so far unique asteroid.

The ESA SSA-NEO Coordination Centre has released the December newsletter.

If you check our current risk list, you will notice that a significant number of objects in the top positions are extremely “old”, discovered in the first decade of the century.

Over the past week, the Near-Earth Object (NEO) community in general, and ESA’s NEO Coordination Centre (NEOCC) in particular, have been involved in an interesting example of the process of...

The "API support" for the NEOCC web services is currently limited to some HTTPS GET requests with raw text-based responses. Note that the API is considered as experimental — pending funding...

It is possible to visualise the orbits of all asteroids in our database by entering their name, provisional designation or catalogue number. The position along the orbit is computed at regular time...

The NEOCC is ESA's centre for observing and computing asteroid orbits and assessing their impact risk.

One month ago, NEOCC team ruled out the possibility that asteroid 2006 QV89 would impact the Earth this September by making a “non-detection”, i.e. observing the area of the sky where the asteroid...

Additional information

The first part of the Discovery Statistics page

The Torino scale is a function of the impact energy and probability of the event, with no reference to the time of impact. In the Palermo scale, the risk posed by a possible impactor is compared to...

The first NEA, (433) Eros, was discovered by Gustav Witt from the Urania Sternwarte Berlin and independently by Auguste Charlois from the Observatoire de Nice, on 13 August 1898. The discovery...

SSA is the acronym of ESA's "Space Situational Awareness" programme, which was the precursor to the current Space Safety Programme. SSA ran between 2009 and 2019. More info at:...

Even if an asteroid misses the Earth, it can come back and hit our planet in a subsequent "return". Whether this happens or not, depends on whether the object passes through well-defined regions in...

On 25 July, an asteroid the size of a football field flew by Earth, coming within 65 000 km of our planet’s surface during its closest approach – about one fifth of the distance to the Moon.

The word NEO stands for near-Earth object, indicating a small body of the Solar System which can come into the Earth’s neighbourhood. A broad classification of NEOs distinguishes NECs (near-Earth...

On 25 March 2015 our website experienced unusually high traffic for a few hours, seven times above our average rate. We tracked this boost of popularity to some news about the flyby of asteroid 2014 YB35 that were circulating on the web around that time.

The month ofApril saw two very important international meetings on NEOs taking place at the ESA ESRIN establishment in Frascati. On g—10 April the Space Mission Planning Advisory Group (SMPAG) met for two days for their third regular meeting.

In recent years, it has become increasingly common for ground-based surveys to discover small objects that seem to be in distant Earth-centred orbits. Most of them turn out to be man-made spacecraft or upper stages of spent rockets residing in Earth’s region.

Some media attention was given to the distant fly-by of asteroid (1566) Icarus. Although the event in itself posed no collision threat whatsoever,Icarus is indeed an interesting object for the history of NEOs.

Two large objects have been observed in the month ofJuly. (85989) 1999 JD6 had a distant encounter with the Earth, while the newly discovered asteroid 2015 OL35 entered our priority list for follow-up observations.

September 2015 Newsletter

During the month of September a news circulated on European media claiming that between 22 and 28 September the Earth would have been hit by meteorites and other cataclysmic events.

Over the past few days there has been a significant media interest in 2015 TB145, a large asteroid that flew past Earth on the night of Halloween. Apart for the popularity of the event generated by the date,the fly-by itself is interesting from a scientific perspective, because it was discovered only three weeks before its closest approach.

November was a month of close approaches of many small objects. A particularly interesting case was 2015 VY105, which came to less than 30 000 km from the Earth’s surface on 15 November.

In the month of December, (29075) 1950 DA, an old NEA, entered the risk list in a peculiar way: the addition is not based on new observations but it is the combined result of an already existing good observational coverage for this object, together with a newly implemented dynamical model now available at NEODYS.

A new release of our NEO Web Portal is on-line at http://neo.ssa.esa.int/. It represents a major update of the SSA-NEO system since it includes a number of new functionalities and an improved graphics. The possibility of visualizing the actual trajectory of an NEO including gravitational perturbations and an enlarged plot at close encounter has been implemented.

This month, while reading this newsletter, you will find an object designated with a “non-standard” name: XDg2F93. Labels like this, not following the standard form of year + letters + numbers,are called “temporary designations”.

We took the opportunity of the ExoMars 2016 launch to organize a ground-based observational campaign. The goal was to test, in a reverse mode, the observational scenario needed to monitor the approach of a small Earth impactor. The spacecraft and other hardware related to the launch was successfully imaged;

On 9 May the planet Mercury will transit the Sun as seen from Earth. Although not an asteroid event, this gives us a chance to talk about how transits have been used in the past to probe the population of small asteroids extremely close to the Sun (the so-called Vulcanoids).

The NEO Coordination Centre is collaborating with the European Commission project NEOShield-2 on the dissemination of NEO physical properties. Our EARN-based physical properties database will be enhanced to host additional data.

The newly discovered asteroid (469219) 2016 HO3 has been attracting the interest of the NEO community becauseof its peculiar orbital path. Having the same period of revolution of the Earth but a higher eccentricity and being properly phased, this object appears to circle our planet in a retrograde “quasi-satellite” orbit with period one year.

2016 NA39 is a newly-discovered asteroid that for a few days in mid-July deserved attention. Because of its large size, around one kilometre, it became the highest rated object with possible impacts in the current century, scoring as high as Palermo Scale of —2.6.

The NEO Coordination Centre web portal is an evolving environment: new services are added whenever ready to be made publicly available. This is the case for two software packages addressing key issues in NEO science: an updated NEO population model and an NEO propagator.

The month of September was unusually rich of close approaches. Nine objects,all with a diameter of about 10 metres, flew by our planet closer than about the distance of the Moon.

The number of known near-Earth asteroids has just surpassed the threshold of 15000. That is a 50% increase with respect to 2013, when the 10000th object was found, highlighting the ever increasing success of ground-based NEO detection surveys.

Whenever a new set of observations for an object is published, our Impact Monitoring routines perform a new search for possibly impacting orbits compatible with such set of observations. The system is capable of detecting all possibly impacting orbits down to an impact probability threshold, named “generic completeness level”.

During 2015-2016 ESA funded the development of two small robotic observatories, called the Test-Bed Telescopes (TBTs). The main goal is to develop and test a fully automated telescope control system to observe NEOs and space debris.

Every month about 40 known or recently discovered asteroids come within 0.05 astronomical units, or about 19 lunar radii, from our planet. In some cases, such as in the month of December 2016,four or even five objects reach their closest approach distance on the same day.

During the past year ESA funded the refurbishment and modernization of the 0.8 m Schmidt reflector located at the Calar Alto Observatory in Spain. The telescope, identified with the MPC code Z84,is now operational and can be remotely controlled.

The closest approach distance is not the only important parameter for assessing the asteroid hazard. The velocity plays a crucial role in shaping the outcome of a close encounter as well as in evaluating the consequences of an impact. The speed at which an asteroid flies by the Earth results from geometrical and dynamical considerations characterizing its pre-encounter orbit.

In the acronym "NEO"the final letter O stands for "Object", because the group is generally understood to include both asteroids and comets that come close to Earth. It is however interesting to note that most aspects of the NEO discovery process we commonly associate with asteroids happened first for comets

Just a few days before the edition of the present newsletter a large bolide crossed the Italian northern sky. The event was observed by many people and in particular by a newly installed fireball network PRISMA (see next page). Such images have been used to determine the trajectory of the entering object.

The month of June 2002, 15 years ago, marked the kick-off of six parallel preliminary studies carried out by ESA’s General Studies Programme (GSP) in order to analyse possible asteroid missions. Three of those studies were devoted to in-orbit telescopes for NEO discovery and characterization, other two were devoted to asteroid rendezvous missions and finally one for asteroid rendezvous and impact.

Near-Earth asteroid 3122 Florence will have a close pass by Earth on1 September when it will be at a closest distance of 0.0472 au (18.4 LD), which makes it a Potentially Hazardous Asteroid (PHA). This Amor object, named after nurse Florence Nightingale (1820-1910), has an estimated diameter of ~4.35 km and was discovered in March 1981 by S.J. Bus at Siding Spring Observatory.

Asteroid 2012 TC4, discovered five years ago by the Pan-STARRS survey,will come back close to Earth on 12 October 2077.It will fly-by at 44 000 km from the surface, providing a rare chance to carefully observe a small known object during its entire approach to our planet.

Asteroid 2012 TC4is the target of an international observing campaign that will culminate this month during its close fly-by with Earth. The object will safely fly at about 44 000 km from the Earth surface, with no chance of collision with our planet.