Sir

In your News Feature on the search for organic molecules in martian soil 'Secrets of the martian soil' (Nature 448, 742–744; 2007), you say that the mass spectrometer on NASA's Phoenix lander will be used on “samples heated as high as 1,000 °C — twice the temperature of Viking's ovens”, which is defined as 500 °C. Of course, the former temperature is only about 65% higher than the latter, since absolute zero is −273 °C. Although this is not a big mistake, it does not aid the understanding of scientific fundamentals by the general public.