0 the point in an object's orbit (= a curved path in space around a planet or star) around the sun at which the object is closest to the sun:
In the low and nominal cases maximum exposure occurs in the southern hemisphere at perihelion, intuitively consistent with a relatively optically thin atmosphere.
Also, the increased daytime period is evident towards perihelion, escalating further the total daily dose.
One, after a sensational first-sighting, seems to have retreated to outer space; its last perihelion was a disappointment.
The general shape of the diurnal profiles between perihelion and aphelion are similar, but dose values vary markedly.
Einstein found that his theory correctly ' predicted, ' actually retrodicted, the numerical value of the perihelion advance.
Einstein's derivation of the perihelion advance, which was based on an approximation, had, however, one blemish: the uniqueness of the solution remained questionable.
When the perihelion passage takes place in northern summer, the maximum temperature is lower in the southern hemisphere, so the soil humidity is higher in the south.
The remaining three orbital elements - the longitude of the ascending node, the argument of perihelion, and the mean anomaly - were each randomly selected from the range 0-360x.
