DEAR DEVIL by Eric Frank Russell
The first Martian vessel descended upon Earth with the slow, stately fall of a grounded balloon. It did resemble a large balloon in that it was spherical and had a strange buoyance out of keeping with its metallic construction. Beyond this superficial appearance all similarity to anything Terrestrial ceased.
There were no rockets, no crimson Venturis, no external projections other than several solaradiant distorting grids which boosted the ship in any desired direction through the cosmic field. There were no observation ports. All viewing was done through a transparent band running right around the fat belly of the sphere. The bluish, nightmarish crew was assembled behind that band, surveying the world with great multifaceted eyes.
They gazed through the band in utter silence as they examined this world which was Terra. Even if they had been capable of speech they would have said nothing. But none among them had a talkative faculty in any sonic sense. At this quiet moment none needed it.
. . .