Despite the recent technological advancements that have aided mankind’s thirst for galactic exploration, astronomers are still yet to truly visualise what the Milky Way, which encompasses our own Sun, looks like. In December 2013 the European Space Agency (ESA) launched its space observatory probe Gaia in a bid to further the understanding of our galaxy and its surroundings and first began star-mapping the sky in 2014. It has been silently at work for the past few years and now its hard work has reached its fruition as ESA has revealed the first block of its fascinating data.
On September 14, 2016, ESA made public the spacecraft’s collated information in its first 14 months of mapping, which includes 1.142 billion stars of the Milky Way that have been 3D mapped to extraordinary precision. Gerry Gilmore, the mission’s UK principle investigator, eloquently stated the significance of the insight that Gaia will provide into our own galactic home. “We don’t actually know what the Milky Way looks like,” he added, “It’s astonishingly difficult, when you’re inside something, to find out what it looks like.”
Although the group of stars that probe had imaged only represent 1% of the whole of the Milky Way, Gaia has already surpassed expectations with the success of these results. It has imaged more stars than previously anticipated and is collecting 40GB of data on a daily basis. Gaia researchers have even suggested that these findings may elude to the possibility that the Milky Way holds more than the 100 billion stars that are currently estimated it contains.
Moreover, through tedious observations of 2 million stars, researchers can now establish the motion of these stars, which may, in turn, provide some idea about how the dark matter may be enveloping the galaxy. The motion data may also propel the discovery of even more exo-planets through observation of the characteristic wobbles of individual stars, with researchers estimating at least 70,000 exo-planet discoveries.
The global community of astronomers can now access the information Gaia has to offer, with a complete evaluation of all data anticipated to take many months or even years. The first published block of results has already massively altered the existing understanding of what our home galaxy whilst the second block of data is due for release in late 2017.
The probe’s mission is anticipated to end in 2019, however, further discussions are being held with a possibility of the mission’s extension to 2024.
– Palwasha Najeeb, Correspondent (Science)