Momentum of the Earth (Linear):
Mass of the Earth: 5.972*10^24 kg ; the weight of the Earth is measured using the equation FG=(Gm1m2)/r2 taking an object that has mass and finding the force that the Earth exerts on it.
Velocity of the Earth: 30000 m/s ; We find the velocity of the Earth by knowing that the Earth travels around the Sun in one year, now we only have to find how far it travels. We have to find the length of its ellipse around the sun, which is approximately a circle (or close enough - this is physics after all where 9.8=10...) So we have to find the radius which is the average distance from the Sun to the Earth which is known as an Astronomical Unit (AU) which is 149,600,000 km. So C=2*pi*r2 ; C=2*pi*(149,600,000,000m)2 and divide that by one year to get the velocity.
Now multiply mass and velocity together to get momentum: 5.972*10^24kg * 30000m = 1.7916*10^29 N*S - pretty big