2012 DA14 : un petit astéroïde croise régulièrement notre trajectoire

[mac.nivolsAdministrateur sécurité]

Ce petit astéroïde de 50 m a été découvert récemment par une équipe amateur lorsqu'il est passé à 7 fois la distance Terre-Lune mais étant donnée qu'il a une période de 366.24 jours, il recroisera l'orbite terrestre aux environs du 15 février 2013 à 24 000 Km, il risque donc de secouer quelques satellites...

Comparaison des trajectoires :

Article complet sur le site de l'ESA : http://www.esa.int/esaCP/SEMWTUAYLZG_index_0.html

15 March 2012

When it whizzes past Earth in 2013, a newly discovered asteroid is going to miss our planet – but not by much. The 50 m space rock is expected to come closer than many satellites, highlighting the growing need to keep watch on hazards from above.

An amateur team discovered the unusual asteroid, dubbed 2012 DA14, on 22 February. Its small size and orbit meant that it was spotted only after it had flown past Earth at about seven times the distance of the Moon.
However, current predictions indicate that on its next flyby, due on 15 February 2013, it will pass Earth at just 24 000 km – closer than many commercial satellites.

"This is a safe distance, but it is still close enough to make the asteroid visible in normal binoculars," says Detlef Koschny, responsible for near-earth objects in ESA’s Space Situational Awareness (SSA) office.

Astronomers in Spain spot 'slippery target'

The asteroid was discovered by the La Sagra Sky Survey observatory, in the southeast of Spain, near Granada, at an altitude of 1700 m, one of the darkest, least light-polluted locations on the European mainland.

"Considering its path in the morning sky, its rather fast angular motion, the quite faint and fading brightness and its orbit high above the plane of Earth’s orbit, it was a slippery target – and easily could have escaped undetected during this Earth visit," says Jaime Nomen, one of the discoverers.

The team use several automated telescopes to scan the sky, and the discovery came somewhat serendipitously after they decided to search areas of the sky where asteroids are not usually seen.

"A preliminary orbit calculation shows that 2012 DA14 has a very Earth-like orbit with a period of 366.24 days, just one more day than our terrestrial year, and it 'jumps' inside and outside of the path of Earth two times per year," says Jaime.

While an impact with Earth has been ruled out on the asteroid’s next visit, astronomers will use that close approach for more studies and calculate the Earth and Moon’s gravitational effects on it.

"We will also be keen to see the asteroid’s resulting orbit after the next close approach in order to compute any future risk of impact," says Detlef.

Half a million undiscovered objects

The La Sagra Sky Survey is operated by the Observatorio Astronomico de Mallorca and has recently joined ESA’s SSA programme. In the future it will provide observations to the asteroid data hub that ESA is developing.

Together with information on space weather and debris, its information will help European scientists and policy-makers understand and assess hazards, particularly if an Earth-threatening asteroid is ever found.

The discovery of 2012 DA14 is particularly significant for the Agency’s SSA office, because it is typical of the estimated half a million undiscovered near-Earth objects up to 30 m across.


“The goal is to be able to spot them at least three weeks before closest approach to Earth.”
"We are developing a system of automated optical telescopes that can detect asteroids just like this one, with the goal of being able spot them at least three weeks before closest approach to Earth," says Detlef.

To achieve this, ESA specialists supported by European industry are planning a network of 1 m-diameter telescopes with a combined field of view large enough to image the complete sky in one night.
The work is continuing under the Agency’s Space Situational Awareness Preparatory Programme.

Detlef Koschny
Head NEO Segment, SSA Programme Office
ESA/ESTEC, Noordwijk, The Netherlands
Tel: +31 71 565 4828
detlef.koschny @ esa.int
Gerhard Drolshagen
NEO Segment, SSA Programme Office
ESA/ESTEC, Noordwijk, The Netherlands
Tel: +31 71 565 4316
gerhard.drolshagen @ esa.int

Comme quoi, à la force de surveiller les gros géocroiseurs, on en oublie d'être attentif aux petits, heureusement qu'il y a les "amateurs" dans ce domaine aussi.

Cordialement.

[VerveineUfologue/enquêteur]

Merci mac pour cette info
le caillou est il sur le plan de l ecliptique ?

Amities

[mac.nivolsAdministrateur sécurité]

De rien,
Je ne sais pas, ce n'est pas marqué dans l'article, mais il y a de très forte chance que oui.

Bonne soirée.

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