Calendar
Mars at Aphelion
Mars will be at the farthest point in its orbit around the Sun on this date - 154,425,919.9 miles.
G. Lippmann, Nobel Prize for optics, (d. 1921)
Jonas Ferdinand Gabriel Lippmann (16 August 1845 – 13 July 1921) was a Franco-Luxembourgish physicist and inventor, and Nobel laureate in physics for his method of reproducing colours photographically based on the phenomenon of interference. - Wikipedia
LunGradCon
OnlineMacke R. J., Opeil C. P., Britt D. T., and Consolmagno G. J. will discuss "Thermal Properties of Lunar Material in Permanently Shadowed Regions" at the 2021 NASA Exploration Science […]
First Quarter Moon
The Moon is at First quarter on this date -it will be visible high in the southern sky in early evening.
Moon at Perigee
Every month, the Moon’s eccentric orbit carries it to perigee, the Moon’s closest point to Earth in its orbit – then 2 weeks later, to apogee, its most distant point from Earth.
Conjunction of Venus & Regulus
The planet Venus will appear a little over 1° from the star Regulus at sunset on July 21st.
Mercury at Perihelion
The planet Mercury is a Perihelion (its closest approach to the Sun) on July 23rd.