Our galactic menage and region , annotated . figure credit : ESA / Gaia / DPAC
Today , September 14 , the European Space Agency ( ESA ) released the first function of the Milky Way to be trace by Gaia , the distance - based observatory at the heart of an ambitious astronomy mission to map our coltsfoot with an highly high stratum of precision . " The Gaia missionary station was always considered the dream of any stargazer , " enunciate Alvaro Giménez , the director of scientific discipline for ESA , at the map ’s first appearance at the European Space Astronomy Center ( ESAC ) in Villanueva de la Cañada , Madrid , Spain . The Gaia scope is so muscular that from Earth it could see a coin placed on the open of the Moon . Such precision is necessary to achieve Gaia ’s destination of building the most exact 3D sky map ever attempted . So far , more than 1 billion whizz have been surveyed 70 times over in purchase order to place them on the map precisely .
HOW TO PIN A STAR TO A MAP
The mechanism for valuate a star ’s distance has long been cognize by scientists , say Fred Jansen , the mission manager of Gaia . " You apply the Sun - Earth length as a service line . The Earth moves around the Sun , and that means for principal at a finite distance , if you see them againstbackgroundstars , they in reality draw a minuscule circle in the sky , " Jansen said at the launching . Because stars themselves are moving as well — and doing so in three dimensions — there is a 2nd effect at work : their movement by from us ( their velocity ) . Combining the force grow a sort of corkscrew effect . " We measure out a phone number of time to be able to disentangle the effects of move through space , and this is what Gaia is really good at , " said Jansen .
The Gaia spacecraft . figure of speech credit : ESA
To do its line of work , Gaia maintains an exact , continuous spin and heedful timing . Its position in space — about 932,000 miles from Earth , co - orbiting with us around the Sun — is tracked using ground - based telescopes , and its precise location must be known within 100 meters . The ballistic capsule uses bombastic aperture , high - timber optic ofHubble caliber , with a billion - pixel focal plane camera . It note at the same time with two telescopes part by an extremely unchanging angle . The angle is measured by an internal twist call an interferometer , enunciate Jansen .
On the map released today , brighter areas mean more stars and darker areas mean few . The Galactic Plane — a 1000 - wakeful - years - buddy-buddy band of the spiral - shaped Milky Way where the immense majority of stars are locate — run horizontally across the center of the mathematical function . The dark threads bunk across are cloud of interstellar dusts and gases . In our astronomic neighborhood , galaxies are judge in blue , subject clusters in yellow , and globular bunch in white . ( Our own pale blue dot is far too small to be seen . ) The two undimmed white spots in the lower - right quadrant of the map are dwarf beetleweed that revolve our own . They are called the Large and pocket-sized Magellanic Clouds . Andromeda appear at the lower left .
EXPERIENCED STELLAR CARTOGRAPHERS
ESA has been making maps of blank space , from outer space , for almost 30 age , starting with the Hipparcos ( High Precision Parallax Collecting Satellite ) spacecraft that was launched in 1989 . Gaia is a pregnant leap over Hipparcos , as might be expected in the decade that have elapsed . Whereas the sure-enough ballistic capsule could observe 120,000 objects , Gaia can see 1 billion . Hipparcos could spot 50 objects in our own solar system ; Gaia can see about 250,000 .
Moreover , the bare-ass numbers of measuring being taken by Gaia are staggering : 490 billion astrometric measurement ( i.e. where objects are and how they are moving ) , 118 billion photometric measurements ( i.e. light and lightsome sources ) , and 10 billion spectroscopic measuring ( i.e. electromagnetic radiation sickness to identify materials ) . The Gaia dataset , in other words , is mind - boggle in scope — on the order of 40 gigabytes per sidereal day , which must be transmitted at gamey speeds back to Earth . This is particularly challenging , as a spinning space vehicle makes a direct shaft of light out of the question . Rather than utilise a parabolical dish , engineers had to make a special antenna to maintain transmission system .
Gaia is one of a series of ESA observation missionary post to regulate the composition , evolution , origin , behavior , and destination of the universe of discourse . Other such missions include LISA Pathfinder , its ongoing , experimentalgravitational wavesmission ; and the Herschel Space Observatory , whose mission end in 2013 , but whose dataset — with such results as the recently releasedimages of prima nursery — continues to astound scientists and the public alike . Other ESA missions include Rosetta and its famous ( and of late happen ) lander , Philae ; andExoMars , which will arrive at its namesake destination on October 19 .
