This Week in History: December 6-12
DECEMBER 6, 1997: Jim Scotti with the Spacewatch program in Arizona discovers the Apollo-type asteroid now known as (35396) 1997 XF11. This asteroid created a major stir the following year when orbital calculations indicated a very close approach to Earth would be occurring in October 2028, and even though subsequent calculations with more data moved …
Comet of the Week: Lovejoy C/2013 R1
Perihelion: 2013 December 22.73, q = 0.812 AU I’ve mentioned in some of the previous “Ice and Stone 2020” presentations that, until the appearance of Comet NEOWISE C/2020 F3 earlier this year, the northern hemisphere had not had what could be considered a “Great Comet” in well over two decades. We did have a moderately bright …
Special Topic: “Active Asteroids”
Ice And Stone 2020 Week 50 Throughout “Ice and Stone 2020” we have primarily been concerned with the objects we call “comets” and the objects we call “asteroids,” which collectively are “planetesimals” left over from the formation of the solar system. From an observational perspective, “asteroids” are stellar in appearance whereas “comets” are diffuse and …
This Week in History: Nov. 29 – Dec. 5
NOVEMBER 29, 1996: A team of researchers led by Stewart Nozette publishes their paper describing the tentative detection of water ice at the moon’s south pole in radar experiments conducted with the U.S. Defense Department’s Clementine spacecraft. This detection has been confirmed by later spacecraft missions, and these efforts, and the overall significance of this …
Comet of the Week: 109P/Swift-Tuttle 1992t
Perihelion: 1992 December 12.32, q = 0.958 AU One of the most prolific comet discoverers of the late 19th Century was the American amateur astronomer Lewis Swift, who did most of his observing from rural New York before relocating to southern California in the early 1890s. Swift discovered his first comet, a 7th-magnitude object, on July …
Special Topic: Sample Retrieval Missions
In most scientific disciplines, if we want to examine an object closely and in-depth, we can collect some kind of sample specimen of that object, take it to our laboratories, and perform any number of direct analysis examinations of that specimen. For the most part, in astronomy we can’t do that; we are usually restricted …
International Space Station Word Search
Humanity marked 20 years of continuous habitation of the orbiting International Space Station on November 2, 2020. We’re celebrating the milestone by posting a variety of articles about the ISS during this historic year. In our latest Word Search puzzle, we’ve hidden 39 words related to the ISS. The words may be placed horizontal, vertical, …
Can plant seeds survive the radiation of space?
Will we someday colonize space? Will our children visit other planets? To achieve goals like these, we’ll need to crack one crucial challenge: how to feed ourselves for long periods away from Earth. A trip to Mars would take months, and exploring the depths of the galaxy would take even longer. Provision of nutritious food …
This Week in History: November 22-28
NOVEMBER 22, 2020: The Apollo-type asteroid (7753) 1988 XB will pass 0.066 AU from Earth. The best visibility will be next week when it travels west-northwestward through Leo, Cancer, and Gemini and will be 15th magnitude. Close approaches by near-Earth asteroids are the subject of this week’s “Special Topics” presentation. NOVEMBER 25, 2005: JAXA’s Hayabusa …
Comet of the Week: ISON C/2012 S1
Perihelion: 2013 November 28.78, q = 0.012 AU I mentioned in the “Special Topics” presentation on “Great Comets” that such objects come by about once a decade, on average. Comet NEOWISE C/2020 F3, which appeared back in July, could perhaps be considered a borderline “Great” comet, but prior to that, the last “Great Comet” for those of …