The Spacewatch project, located in Arizona, is probably the oldest of the asteroid survey still active today. They were the dominant discoverers of new asteroids in the ‘gos, and the pioneers of using CCDs to find new NEOs.

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.

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.

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 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.

September 2015 Newsletter

October 2024 Newsletter

For the first time in the history of NEA observations more than 2 000 new NEAs have been discovered in one calendar year, resulting in a monthly average of nearly 170 new asteroids. In addition, 2017 was the fifth year in a row with NEA discoveries above a thousand.

Current NEO statistics About 4% of the known NEO population is in the risk list. This value has remained roughly constant over the past years even if the discovery rate has increased.

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

Current NEO statistics During the last month the global numbered asteroid catalogue (including main belt asteroid) surpassed the threshold of half million objects. The number of known NEOs surpassed 17 000, thanks to more than 300 discoveries in a single month.

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.

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.

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.

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”.

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.