… by

European Space Agency .

It's a bit vexing that they don't say what the scale of the colour coding is! … but it's almost certainly in mGal (milligalileos: 1Gal = 1㎝/s²) , because that's the unit that gravitational anomaly is very often - or even usually - expressed in … so, since the mean gravitational acceleration is ~981Gal the values shown are close to the proportional variation in parts-per-million: very slightly greater than it.

But the resolution's reasonably decent: 1920×1266 … although a lot of the vertical component of that is taken-up by the border. 'Bumpy sphere' maps of gravitational anomaly are often encountered … but in many ways I prefer to have a straightforward 'usual' projection of the map.