Home Remedies for Whiter Teeth. Some people still prefer the age-old home remedy of baking soda and a toothbrush to gently whiten teeth at home. Also, some foods such as celery, apples, pears, and carrots trigger lots of saliva, which helps wash away food debris on your teeth.
Roche limit. n. The smallest distance at which a natural satellite can orbit a celestial body without being torn apart by the larger body's gravitational force. The distance depends on the densities of the two bodies and the orbit of the satellite.
As it approaches our Roche limit (approximately 28,300 km from the surface), it begins to break up 23.6 minutes before impact. At about 120 km above the ground the pieces encounter a tenuous atmosphere. In the next few seconds before impact many more pieces are created from atmospheric shock.