The European Space Agency plans to launch the spacecraft that will map the Earth's gravity and help understand the processes from the Earth's inner layers affecting the upper layers
The GOCE mission of the European Space Agency, which will be launched in September 2008, will investigate the gravity of the Earth and the circulation of the oceans. The mission will increase our understanding dozens of times, and will explore in depth one of the most significant forces of our planet - gravity.
Goss is equipped with advanced tools aimed at mapping from space the "attraction zones" of a ball in Israel and creating the most detailed map ever created. As the most advanced mission in its field ever launched into space, Goss' data will serve a wide range of fields ranging from oceanography, physics, geodesy, weather research, climate change research and many other fields.
Although it is common to think that gravity is a constant value, this is not the case and it changes from place to place. The changes result from a large number of factors such as the rotation of the Earth, the location of mountains and oceans and changes in the density of the atmosphere in different regions of the Earth. The mission will investigate the influence of the forces and at a later stage it will be possible to understand the forces from the inner layers of the Earth affecting the upper layers.
The Goss mission will map these changes throughout its lifetime, approximately 20 months, and create a visual model. The model will supplement information and perhaps even explain various phenomena such as the circulation of the oceans and the rise of the sea level, two phenomena derived from the warming of the earth.
Since the gravitational signal is stronger closer to Earth, Goss's 5-meter-long antenna was designed to read information through layers of the atmosphere, at an altitude of 250 km above sea level. This is the first low-orbit mission designed according to the concept of gradiometry - a measurement of Acceleration differences at constant distances to measure density of mass.
Goss is equipped with three pairs of ultra-sensitive accelerometers which are organized in three dimensions and respond to minute changes in the Earth's "gravitational pull" as they move along the orbit around the Earth. Because of their different locations, they experience slightly different gravitational acceleration. And so the three axes of gradiometry enable the simultaneous measurement of six independent but complementary components of gravity. Gradiometry is the heart of the satellite and in order to measure gravity there must be no moving parts, as a result the entire spacecraft is actually an extremely sensitive measuring device, and hence the importance of the mission.
Lagos has several goals including mapping the Earth's gravitational field, measuring changes in gravity with an accuracy of 1-2 centimeters and achieving a spatial resolution better than 100 km.
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I don't know who EURA is, but we are still very far from understanding everything about the force of gravity.
Good Day
Sabdarmish Yehuda
At EURA they have already discovered everything about the power of the liver. You can ask them.
Yehuda, your last comment bothers me and seems to me to be out of place.
Michael's explanation is correct. All the distances we would measure are from the center of the earth (the center of gravity for that matter) and the reason is that the distinct unevenness of the surface barely affects the location of the center. In any case, we would only measure the distance difference.
And changing the distance of the spaceship from that center point is exactly what would have made it possible to measure the change in gravity, and this is because the earth is not uniform and therefore there is a change in gravity. And that is exactly what is being measured. And so your claim of non-uniformity on the earth is a hidden and clear assumption in Michael Love Ner's response.
This is true.
I just didn't want to complicate things (and the above explanation does not define anything that can be calculated without knowing all the details while the calculation I described gives a very good approximation when it comes to a route that is about 250 km from the ground) because what is important is that measuring the distance from the ground is not relevant .
The force of gravity is according to the center of gravity only in uniform spherical bodies. In any other body it doesn't have to be like that. The determining rule is that each particle exerts proportional gravitation inversely to the square of the distance from it.
For example, if we want to know what is the gravitational force exerted on us by a rod whose two ends are in a straight line from us and away, then the part closest to us exerts a greater force of attraction than the part far from us, therefore in SA squared the distance will be closer to us than the center of gravity of the rod.
Did you understand?
If not then it doesn't matter.
Just because
Sabdarmish Yehuda
A. Ben Ner:
The surface of the earth is not smooth.
There are mountains and valleys that affect the distance much more than anything else.
Besides, the distance by which the force of attraction is determined is the distance from the center of gravity and not the distance from the surface.
It is not written in the article, but it seems to me that it is also possible to use a measurement based on a precise distance measurement, possibly by a laser beam, between the spacecraft and the spacecraft. The idea is that the distance changes with the changes in gravity. And so by measuring the small changes (2-1 cm) in distance, you can calculate the changes in gravity.
In a rigid body only the center of gravity is in free fall. All other points in the body experience gravity and simulated forces as a result of persistence.
Basically - this is exactly the reason why there are high tides on the surface of the earth that fall freely around the sun.
Gravitation can be calculated from the differences between the forces at the various points
agree.
"Goss's antenna is 5 meters long" - what's the connection, it says it's based on accelerometers.
Good point.
When you are in free fall, you cannot feel gravity.
I don't understand how the spacecraft can feel the acceleration acting on it.
probably not
Couldn't a higher accuracy be achieved by measuring the changes in the height of the spaceship itself which is in free fall all the time?