April 2023 Newsletter

June 2023 Newsletter

May 2020 Newsletter

November 2020 Newsletter

October 2020 Newsletter

May will likely be the last month before summer with an average rate of NEO discoveries. Starting in June, most surveys in the South-West of the United States will likely temporarily decrease their productivity due to the summer monsoon season.

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.

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.

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.

In our newsletter of December last year, we devoted this section to the discovery of asteroid 1997 XF11. Twenty years ago, on 11 March 1998, astronomer B. Marsden released an IAU Circular stating that the asteroid would pass within 0.002 au of Earth on 26 October 2028.

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.

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.

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;

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.

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.

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.

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.

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).

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.

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.

September 2015 Newsletter

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.

September 2022 Newsletter

April 2021 Newsletter

August 2020 Newsletter

September 2020 Newsletter

April 2020 Newsletter

The month of December this year marks the fifth anniversary of the launch of ESA’s Gaia spacecraft. The mission, now operating continuously near the Earth-Sun L2 Lagrangian point, has already revolutionized many fields of astronomy, thanks to the broad and exquisite quality of the data it is producing.

This year on 8 February marks the 50th anniversary of the fall of the Allende meteorite, the largest carbonaceous chondrite ever found. The atmospheric entry and impact happened at night local time, and were therefore well observed over the entire Northern Mexico. About 2 tonnes of fragments were later collected on ground in a strewn field of about 50 km size.

On 1 February 2019 a bright daytime fireball was seen by multiple eyewitnesses around the area of Gulf of Mexico. It exploded over the western tip of Cuba, producing a significant shockwave felt by local residents, and the fall of a large number of stony meteorites, mostly near the village of Viflales.

March 2020 Newsletter

The Fly-Eye Telescope is an innovative project of ESA‘s SSA-NEO Segment that will focus on survey and follow-up of NEOs. Another important milestone on the way to build the telescope was achieved: from 30 July to 1 August ESA attended the acceptance test of the equatorial mount at its production site in Verona, Italy.