Comet of the Week: 2P/Encke
Perihelion: 2020 June 25.85, q = 0.337 AU In the early 19th Century the idea that comets might return to the inner solar system on a regular basis was still a bit of a novelty. This had been successfully demonstrated by the British astronomer Edmond Halley when the comet that now bears his name returned …
Special Topic: Orbits and Future Returns
“Ice and Stone 2020” participants have undoubtedly noticed that I have often discussed how this-or-that comet or asteroid will be returning to the inner solar system or passing by Earth at some point in the future, and perhaps have wondered how such things are determined. In principle, the processes by which such events are calculated …
Shuttlewagon delivers Artemis rocket boosters to KSC
Furthermore, it has been 10 years since the last SRBs arrived at KSC for the final NASA Space Shuttle mission. After the ten 10 SRB segments are stacked vertically they will form the two twin 177-foot-tall (53.9-meter) five-segment Solid Rocket Boosters for NASA’s gargantuan SLS Moon/Mars rocket. Together the twin SRBs will provide more than …
This Week in History: June 14-20
JUNE 14, 1770: The renowned French comet hunter Charles Messier discovers a moderately bright comet in Sagittarius. 2½ weeks later this comet passed just 0.015 AU from Earth, the closest confirmed cometary approach to Earth in history. The comet, named after Swedish mathematician Anders Lexell, who computed its orbit, was later perturbed into a much …
Comet of the Week: LINEAR C/2001 A2
Perihelion: 2001 May 24.52, q = 0.779 AU At the beginning of the 21st Century the discovery of comets and near-Earth asteroids was dominated by the first of the comprehensive sky surveys, the LIncoln Near-Earth Asteroid Research (LINEAR) program run by MIT’s Lincoln Laboratory and based at White Sands Missile Range in New Mexico, that …
Special Topic: Lunar and Planetary Impacts
Ever since the Italian astronomer Galileo Galilei turned his primitive telescope towards the moon on November 30, 1609 and saw them for the first time, we’ve known that the moon is covered with craters. These come in all sizes, from very large ones several hundred km across down to meter-size and smaller. For a long …