Astronomers have taken a meteoric leap closer to discovering how our Solar System began, unveiling the most detailed atlas of the Milky Way in history.
UK researchers, backed by funding from the UK Space Agency, produced a precise 3D map of our Milky Way galaxy using the cosmic treasure trove of data collected from the Gaia satellite, known as the ‘Galaxy Surveyor’.
The cosmic data – co-ordinated by the Institute of Astronomy in Cambridge – will enable astronomers, for the first time, to measure the mass of the galaxy by examining the acceleration of the Solar System. This ability will give us clues to the origins of our star system and could help confirm just how quickly the Universe has expanded since it began.
How does Gaia work?
- The mission carries two telescopes, which it scans across the Milky Way from a location about 1.5 million km from Earth.
- The telescopes’ mirrors throw their captured light on to a huge, one-billion-pixel camera detector connected to a trio of instruments.
- It is this ultra-stable and super-sensitive optical equipment that Gaia uses to pick out its sample of stars with extraordinary precision and confidence.
- The called-for specification was to get to know the brightest objects’ coordinates down to an error of a few micro-arcseconds.
- This angle is equivalent to the size of a pound coin on the Moon as seen from Earth.
- In addition to their position and proper motion, the stars are having their physical properties analysed by Gaia.
- Its instruments are acquiring vital statistics like temperature and composition. These are markers needed to help determine the stars’ ages
Science Minister Amanda Solloway said:
Gaia is located at a Lagrange point, a gravitationally stable spot in the Sun-Earth system, called L2, which is located about 930,000 miles (1.5 million kilometres) from Earth in the opposite direction from the Sun. It has so far measured the positions and brightness of almost two billion stars, as well as detailing their positions, magnitudes and colours.
At Lagrange points, spacecraft are free from the tidal shaking caused by our moving Earth-Moon system. Gaia is also far enough from Earth that the light emanating from our planet will not interfere with observations.
Caroline Harper, Head of Space Science at the UK Space Agency, said:
The information collected by the satellite is analysed back on Earth by the Gaia Data Processing and Analysis Consortium (DPAC), of which the UK is a major partner. The UK Space Agency, together with the Science and Technology Facilities Council (STFC), funds the Mullard Space Science Laboratory and the Universities of Cambridge, Edinburgh, Leicester who make up the UK contribution to the group.
The data has been co-ordinated and prepared at the Institute of Astronomy in Cambridge and all of the mission’s data has been made available to the public so they can help identify interesting phenomena in this massive cosmic treasure trove.
Dr Floor van Leeuwen of the Institute of Astronomy at the University of Cambridge, said:
The European Space Agency (ESA) launched its Gaia mission in 2013. The mission’s name was originally an acronym for Global Astrometric Interferometer for Astrophysics, but interferometry is no longer the method by which the mission does its work.
Its goal was to update and extend the work of a previous satellite from the 1980s/90s called Hipparcos, which was an observatory that created the go-to Milky Way catalogue for its time.
This astonishing chart of our cosmic neighbourhood mapped the precise position, brightness, distance and proper motion (that sideways movement on the sky) of 100,000 stars.
With its first release of data in 2016, Gaia increased the number of stars with usefully measured distances in the Milky Way twenty-fold.
The UK Space Agency contributes £374 million a year to ESA. This membership allows UK scientists to collaborate on a range of programmes, from Earth Observation satellites and Mars Rovers, to advanced telecommunications and commercial applications. The UK Space Agency has already contributed £19 million to Gaia on processing and analysing the findings and STFC has invested an additional £2.4 million into supporting the catalogues derived from the data.