Scientists from Tel Aviv University take part in international space project

Space vehicle 'Gaia' will launch on Thursday to explore Milky Way galaxy over five-year period.

By JUDY SIEGEL-ITZKOVICH
TAU space vehicle Gaia 370 (photo credit: TAU)
TAU space vehicle Gaia 370
(photo credit: TAU)
Astronomers from Israel and all over the world will on Thursday send to space a vehicle named Gaia, which is expected to bring about a “revolution in the understanding of our galaxy,” according to participating Tel Aviv University scientists.
Prof. Shay Zucker – of the geophysics and atmospheric and planetary science department – who, with colleagues, will analyze data collected from the unmanned space ship. Zucker said that the “data that it will send back to Earth will be as accurate as determining the location from Earth of a grain of sand on the Moon with a millimeter’s accuracy.”
Gaia will carry a telescope and other equipment that will map with unprecedented accuracy more than a billion stars and receive a 3-D map of the Milky Way, the galaxy in which our solar system is located. The space vehicle was built by the European Space Agency at a cost of more than two billion euros.
A huge amount of data is expected to expose new insight on the creation and development of the Milky Way and even its history in the next several billion years, Zucker said on Tuesday.
In addition, it is expected to discover hundreds of thousands of planets that revolve around other planets, survey asteroids in our solar system and supply hints of dark energy – the mysterious factor that apparently accelerates the spread of the Universe.
It has taken more than a decade to build the space vehicle, and it is due to be launched on Thursday aboard a Russian Soyuz missile from the launching pad of the European Space Agency in French Guiana. The moment it reaches its permanent orbit, several months will be needed to operate its delicate equipment. Afterwards, Gaia’s mission will continue for five years, during which it will document the location, clarity and temperature of every heavenly body that passes its visual field, including a billion stars.
The TAU scientist said that there are more than a billion pixels in Gaia’s “camera,” making it exceedingly accurate up to 10 microseconds. After its work is completed, an exact 3-D map will help us answer questions related to the origin of the Milky Way, he added.
Like Earth, Gaia will revolve around the Sun once a year. Like 3-D vision using two eyes, the measurement of each star from a somewhat different location over the year will make it possible to measure depth – that is, the distance from Earth.
The super-accuracy will provide new ways to examine the veracity of Albert Einstein’s General Relativity Equations, using more accurate measurements of the movement of celestial bodies in the solar system that are close to us. These measurements, together with the movement of stars in the galaxy, are also expected to provide information on the nature of dark matter, that in a certain way functions in the opposite direction of the force of gravity, Zucker continued.
The exact mapping will also make it possible to identify the movement of stars in the galaxy and bring discoveries of planets circling other stars by discovering the movement that a planet makes on its mother star.
Another way is by viewing changes of the clarity of the star that takes place when the planet hides part of its mother star.
Zucker’s work focuses on discovering those differences of clarity resulting form such planets.
Together with his research student (and now post-doctoral student at the Weizmann Institute of Science) Dr. Yifat Dzigan, they suggested ways to use observations from Earth to improve the changes to discovery these planets.