NEO Coordination Centre

 

Precursor services

 

Current number of known NEAs:
24809
Current number of NEAs in risk list:
1102
Last update: 2021-01-17 11:02:43 UTC

Newsletter

NEOCC Newsletter: January 2021

05 January 2021

The ESA S2P-NEO Coordination Centre has released the January 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 http://neo.ssa.esa.int/web/guest/subscribe-to-services.

 

 

News

1998 KY26 - recovering the target of the Hayabusa2 extended mission

23 December 2020

Asteroid 1998 KY26, the target of the extended mission of Hayabusa2. Image stack obtained with the Very Large Telescope of the European Southern Observatory. Credit: ESO / ESA NEOCC

On 6 December 2020, JAXA's Hayabusa2 spacecraft successfully completed its primary mission with the delivery of the sample container to Earth. Despite the great success of the project, the probe's mission might not be over yet. An extended mission is currently being considered: it will allow both a fly-by of a numbered asteroid, (98943) 2001 CC21, and more importantly a rendezvous with 1998 KY26, a small ~30 metre near-Earth asteroid first discovered in 1998 by the US-funded Spacewatch survey.

This target is particularly interesting, for a variety of reasons. It will, for example, be the first rendezvous with a tiny and fast-rotating asteroid. It is also an object that has been well observed with radar during its discovery apparition in 1998. This has allowed astronomers to derive an accurate tridimensional model of its shape.

However, despite the excellent characterisation effort back in 1998, the orbit of this asteroid was not known well enough to safely navigate the spacecraft. A recovery was needed, and the perfect opportunity was happening right now.

Our team, in the framework of our collaboration with ESO on near-Earth asteroids, was able to use ESO's VLT to target 1998 KY26 on 10 December 2020. At the time of the observation, the object was expected to reach magnitude 25.5, thus requiring very large telescopes. Recovering an object only observed 22 years earlier might appear challenging but, in this particular case, we could take advantages of the excellent radar detections obtained during the discovery apparition. This allowed the determination of a reasonably accurate ephemeris, with an uncertainty that could fit inside VLT's field of view. The object was successfully detected in the first set of frames, and then confirmed with an independent set of images collected two nights later. Around the same time, a Japanese team at the Subaru telescope also observed the target, providing an independent confirmation of the detection.

With the addition of our new observations, it is now possible to plan the mission in more detail. The object will become visible again in 2024, and observations collected during that apparition will be crucial to ensure the successful navigation of the spacecraft to the target, which should be reached in 2031.

 

News

Record breaking close approach of asteroid 2020 VT4

23 November 2020

On 14 November 2020 the NASA-funded ATLAS survey telescope on Mauna Loa, in Hawaii, detected a new magnitude 18 object, and immediately followed it up. After an observed arc of about 2 hours, it became evident that the new object was a small asteroid quickly receding from Earth, and it had come pretty close to our planet the previous day. But how close? With this initial arc, the answer was still too uncertain, but it was roughly in the thousands of kilometres, if not less. A remarkably close miss.

Fortunately, radially receding objects tend to be easy to follow-up, because their positional uncertainty does not grow too quickly with time. And in fact, just a couple of hours later the Glenlee Observatory in Australia obtained some additional observations, and with them it became evident that the approach had been even closer. This small ~10 metre asteroid had just flown over the South Pacific Ocean at a distance of less than 400 km from the surface of the ocean, by far the closest non-impacting asteroid ever observed while in space.

Over the next few days, other observatories obtained astrometric data, including our own team with ESA's OGS telescope in Tenerife, and we now know the fly-by circumstances extremely well. The closest approach happened over a pretty isolated spot of ocean a few hundred kilometres East of French Polynesia. The lowest altitude reached was 370 km, with a precision of a couple of kilometres, and we can determine the exact time of closest approach to better than a minute.

The object has now been permanently designated 2020 VT4, and it will probably hold the record of the closest non-impacting asteroid for a long time, given the extremely narrow miss at this passage near our planet.

 

On the left: 2020 VT4 observed with ESA's OGS telescope in the evening of 16 November 2020, three days after the closest approach, when it was already 2.2 million kilometres away from our planet. At the time of the observation the small ~10-metre object was already as faint as a magnitude 21 starOn the right: Animation of the Earth close approach trajectory of asteroid 2020 VT4 as seen from the Ecliptic North Pole. Each new animation frame represents a time variation of one hour in the real trajectory. Credits: ESA / NEOCC

CAFS

NEOCC Close Approach Fact Sheet: 2020 SW

22 September 2020

The ESA S2P-NEO Coordination Centre has released a Close Approach Fact Sheet (CAFS) for asteroid 2020 SW, passing by Earth on 24 September. 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 http://neo.ssa.esa.int/subscribe-to-services.