We are still learning about our own backyard.
Astronomers have confirmed a 1961 observation of two dust clouds that are essentially "satellites" orbiting the Sun with the Earth at a distance similar to that of our Moon. These dust clouds have formed at two locations that are fairly stable gravitationally.
|Artist’s impression of the Kordylewski cloud in the night sky (with its brightness greatly enhanced) at the time of the observations. Credit: G. Horváth|
They are exceptionally faint which is why it took so long to confirm their presence. They consist of dust grains which could come from comets, asteroids and planetary impacts. Dust is very common and present everywhere in our solar system. Our Moon has a permanent lopsided dust cloud, the Zodiacal Light is composed of dust grains and Earth is bombarded daily by dust.
|Mosaic pattern of the angle of polarization around the L5 point (white dot) of the Earth-Moon system. The five rectangular windows correspond to the fields of view of the imaging polarimetric telescope with which the polarization patterns of the Kordylewski dust cloud were measured. Credit: J. Slíz-Balogh|
Our own solar system is such an enigma.....we are searching for a major planet in its distant depths and will be flying by a denizen of the deep solar system on New Year's Day 2019 - Ultima Thule - with the New Horizons spacecraft.
Who knows what else lurks in our midst?
The joy is in exploring and finding out.
Sky Guy in VA