Engineers Tom Stockman, Gabriel Monroe, and Samuel Cordner simulated planetary positions over 10,000 years and published their findings in a commentary in Physics Today in 2019. ^[1] Mercury is the closest planet, on average, to every planet in the solar system, including Neptune which is five billion kilometers away. ^[2] The study found that averaged over 10,000 years, Mercury is 1.04 astronomical units away from Earth on average, making it the closest planet. ^[3] Venus is commonly cited as Earth's closest planetary neighbor because its orbit is next to Earth's and it swings within about 38 million kilometers at closest approach. ^[4] NASA's guide states that on September 18, 2026, Venus will reach peak brilliance for its evening appearance, shining as a brilliant point of light low above the western horizon shortly after sunset, outshining every star around it. ^[5] NASA's What's Up for September 2026 specifies that from September 14 to 20, the Moon will pass near Antares, the bright reddish star marking the heart of Scorpius, and the Teapot asterism in Sagittarius, and that dark skies may reveal the center of the Milky Way as hazy 'steam' rising from the Teapot's spout. ^[6] On September 26, 2026, the Harvest Moon will rise in the east shortly after sunset, appearing near Saturn and Neptune; Saturn is visible to the naked eye while Neptune, at magnitude 8, requires binoculars or a telescope. ^[7] The September equinox occurs on September 22, 2026, when the Sun is directly above Earth's equator and day and night are nearly equal, marking the start of fall in the Northern Hemisphere and spring in the Southern Hemisphere. ^[8]