WHAT would it take to map a billion stars? How about a billion-pixel camera?.Scientists hope to glean more clues about the origin and evolution of the Universe, our own galaxy in particular, The Milky Way, when a camera of this incredible scale is fitted to the Gaia space telescope. When will this happen? Sooner than we can ever imagine! As a matter of fact, in a few days’ time!

What is the Milky Way?
The Milky Way is the galaxy that contains our Solar Systems. The term “Milky” is derived from its appearance as a dim glowing band arching across the night sky, the individual stars of which cannot be distinguished by the naked eye.

The Milky Way galaxy is assumed to have some 100,000–120,000 light-years (a unit of astronomical distance, equivalent to the distance that light travels in one year, which is 9.4607 × 1012 km, or nearly 6 million miles) in diameter, which contains 100–200 billion stars. It may contain at least as many planets as well. The Solar System is located within the disk, about 27,000 light-years away from the Galactic Centre, on the inner edge of a spiral-shaped concentration of gas and dust called the Orion–Cygnus Arm. The stars in the inner 10,000 light-years form a bulge and one or more bars that radiate from the bulge. The very centre is marked by an intense radio source named “Sagittarius A”, which is likely to be a supermassive “black hole”.

What is a galaxy star?
A star is a massive, luminous sphere of plasma, held together by its own gravity. The nearest star to Earth is the Sun, which is the source of most of the planet’s energy. Some other stars are visible from Earth during the night, appearing as a multitude of fixed luminous points, due to their immense distance.

Black Hole
A black hole is a region of space-time, the gravitational pull of which prevents anything, including light, from escaping. Around a black hole, there is a surface called an “event horizon” that marks the point of no return. The hole is called “black” because it absorbs all the light that hits the horizon, reflecting nothing.

What are pixels?
The word “pixel” means a picture element. Every photograph, in digital form, is made up of pixels. They are the smallest unit of information that makes up a picture. Usually round or square, they are typically arranged in a 2-dimensional grid.

Resolution
The number of pixels in an image is sometimes called the resolution, even though this is a bit of a misuse of the term. If we are using the term to describe pixel count, one convention is to express resolution as the width by the height, for example, a monitor resolution of 1280×1024. This means there are 1280 pixels from one side to the other, and 1024 from top to bottom.Another convention is to express the number of pixels as a single number, like a 5- megapixel camera (one megapixel is equal to a million pixels).

With all the distances, time-consuming, gravitational risks, the Space Agency is ready for “picture taking”; Earth, as never seen before.

Gaia, which is due to liftoff from French Guiana, has been tasked with mapping the Milky Way in greater detail than ever before. Yes, my fellow Guyanese! It’s going to take place not far from us! If we look with specific hi-tech equipment, maybe we can see the takeoff from here. How incredible that would be!

Designed and built for the European Space Agency (ESA), the makers say the telescope is so sensitive and precise that it could measure a person’s thumbnail from the Moon; or to put it another way, detect the width of a grain of human hair from 1,000km (620 miles) away.

The Mission’s aim is to build a three-dimensional picture of our galaxy, measuring precise distances to a billion stars. Even this is a small fraction of the Milky Way, as astronomers believe there are at least 100 billion stars in our galaxy.

Gaia is also expected to log a million quasars beyond the Milky Way, and a quarter-million objects in our own solar system, including comets and asteroids.

The spacecraft cost £400M (US$549M) to build, but the total cost of the mission would come to £740M (US$1.02B) when the expense of the launch and running the mission for its projected five-year lifetime are included.

Gaia will be used to carry out work analogous to the cartographers who surveyed the Earth in the 19th and 20th Centuries; building up the first accurate charts of the cosmos; and helping us better understand the structure, history and fate of the galaxy we live in.
One of Gaia’s objectives is to help in the hunt for exoplanets — new worlds beyond our own solar system.

NASA’s mission has so far confirmed the existence of 167 exoplanets, with hundreds more being investigated, but Gaia will likely discover thousands of new planets, while further missions will be able to uncover more details about them.

We really need more projects like this, not just to map the galaxy, but to get a more in-depth idea about what is actually in our solar system, and increase our ability to locate potential dangers to the planet in time to react to them. Looking forward to seeing some awesome pictures!