How strong is a covalent bond?

The rupture force of single covalent bonds under an external load was measured with an atomic force microscope (AFM). Single polysaccharide molecules were covalently anchored between a surface and an AFM tip and then stretched until they became detached. By using different surface chemistries for the attachment, it was found that the silicon-carbon bond ruptured at 2.0 +/- 0.3 nanonewtons, whereas the sulfur-gold anchor ruptured at 1.4 +/- 0.3 nanonewtons at force-loading rates of 10 nanonewtons per second. Bond rupture probability calculations that were based on density functional theory corroborate the measured values.     

How long is the day on Saturn?

Determining a planet's rotation period can be difficult if the planet lacks a solid surface. However, for planets with an internal magnetic field, emissions at radio wavelengths are modulated by the planet's rotation rate. The latest results from the Cassini spacecraft seem to indicate that Saturn's rotation rate has slowed down by 6 minutes since the Voyager 1 and 2 spacecraft flew by the planet in 1980 and 1981, but it is unclear whether a slowdown has in fact occurred. Future data collected by Cassini may be able to resolve the question.