24 December 2013
Our Galaxy, the Milky Way, in infrared light
Credit: NASA/JPL-Caltech/S. Stolovy
On 19 December 2013, the European Space Agency (ESA) launched the Gaia spacecraft, an ambitious mission, to accomplish mapping and cataloging the precise positions and distances of over a billion stars, located in our Galaxy and some other galaxies. The data will allow producing the largest and most accurate three-dimensional map of the Milky Way Galaxy ever. Gaia will also perform observations of basic physical properties of the stars, such as brightness and color. Intriguingly, its observations are expected to yield numerous discoveries of exoplanets, planets orbiting outside the solar system.
Gaia launched aboard a Russian Soyuz rocket, from the Guiana Space Centre in French Guiana. The Gaia program cost is about US$1 billion.
Gaia is now voyaging in space, toward its orbit, located about 1.5 million km away from Earth. It will orbit a point, beyond the terrestrial orbit, where it can maintain a fixed position, relative to both Earth and the Sun. Gaia’s orbital period will be about 180 days, and its orbit has dimensions of 340,000 × 90,000 km.
References
The European Space Agency
Wikipedia
Aymen Mohamed Ibrahem
Senior Astronomy Specialist