Tag Archives: Astrometry

Enter GBOT

We should all know by now that Gaia is destined to study the motions and locations of 1 billion stars, but did you know that in order to achieve this goal, the precise location of the spacecraft itself is needed to an extremely high precision? In addition to the expert tracking methods utilised by ESA’s mission operations team at ESOC, ground- based observatories also provide important data. Enter GBOT, the Ground Based Orbit Tracking campaign that utilises a network of small-to-medium telescopes aiming at doing just that. In fact, GBOT is committed to deliver one set of data per day, which allows the determination of Gaia’s position good to 20 milli arcseconds. GBOT’s...

Stories of the stars

Gaia, the billion star surveyor. This is the mission slogan. A billion stars. One thousand million stars… That is a lot. Really a lot of stars. If the final catalogue with just the summary of all data accumulated by Gaia were printed and all volumes were nicely aligned in my bookshelf, the row of 53,542 volumes would extend 1.3 km (and this would only be the summary data of all non-special stars). So, I hope you appreciate the point that a billion stars is really a lot. This is also what one of the space enthusiasts that visited the open day of the European Space Research and Technology Centre (ESTEC) a few...

On the edge of the possible

It is probably hard to overestimate the effort required to coordinate the Gaia hardware and software development. While the industrial consortium EADS-Astrium developed the actual satellite and onboard software, the Data Processing and Analysis Consortium (DPAC) is responsible for the scientific data processing. As explained in an earlier blog entry, DPAC consists of several hundred people in dozens of scientific institutes spread all over Europe. Because the scientific requirements of the Gaia measurements are on the edge of what seems physically possible, every aspect of the hardware must be understood and calibrated to an unprecedented level – I will give an example below. This has led to a constant exchange between scientists...

Some Gaia numbers

We have heard and read many numbers about Gaia: the number of stars and other objects that it will observe, the maximum observable magnitude, the microarcsecond of accuracy and the remarkable focal length of 35 m. We have also read that such a powerful telescope on Earth would be able to detect a button on the spacesuit of an astronaut on the Moon. But let’s look at more hidden numbers. It took over 3.5 million hours to study, design, build and test Gaia. That’s about 300 people working full time for 7 years, spread over 74 different companies and 16 countries. Meanwhile the design and implementation of the science and the operations...


Mapping the Milky Way with Gaia

Latest ESA Euronews video looks at Gaia and explains how it will scan the sky with powerful new eyes, mapping the Milky Way in unprecedented detail.

Gaia – Surveying a billion stars

Welcome to ESA’s Gaia blog! Gaia is a global space astrometry mission. It will make the largest, most precise three-dimensional map of our Galaxy by surveying more than a thousand million stars. In this blog we’ll cover the activities from Kourou from once the spacecraft has left the clean room in Toulouse until launch. And we’ll include guest blogs from outside of Kourou – to give you an idea of the other things that are happening in the wider Gaia community. Details shortly…Watch this space!