Ice and Stone 2020 Companion Glossary
We hope you are enjoying reading the weekly Ice and Stone 2020 content from astronomer Alan Hale. For those who might not be as versed in astronomy terms, he’s put together this glossary of technical terms, many of which are regularly used within the weekly educational content. A Absolute magnitude: for a comet or asteroid, …
This Week in History: March 22-28
MARCH 22, 2016: The tiny Comet PANSTARRS P/2016 BA14 passes just 0.024 AU from Earth, the closest known cometary approach to Earth thus far in the 21st Century and the third-closest known cometary approach to Earth in history. Despite its closeness, it was never brighter than 13th magnitude. This and other close comet approaches to …
Comet of the Week: Hyakutake C/1996 B2
Perihelion: 1996 May 1.40, q = 0.230 AU Following the discovery of Comet Hale-Bopp in mid-1995, the entire world was awaiting its expected good show in 1997. But while we were waiting, another comet came by and provided another stunning show. This object was discovered on January 30, 1996 by a Japanese amateur astronomer, Yuji …
Special Topic: “Small Bodies” and the Electromagnetic Spectrum
The “visible” light that our eyes see, and that most of our telescopes detect, is only a very small part of the electromagnetic spectrum. The full EM spectrum encompasses everything from the long-wavelength, low-frequency, low-energy radio waves, on down through infrared, then “visible” or optical light, and then into the shorter-wavelength, higher-frequency, and higher-energy ultraviolet, …
QuizMe: Jupiter
The planet Jupiter is the second featured topic in our new QuizMe series of educational content. Put your knowledge to the test with these 10 questions about the planet. If you would like to brush up on your knowledge about the Jovian system before taking the quiz, we suggest reading this article. Author Chase Clark
QuizMe: Mercury
The planet Mercury is the first featured topic in our new QuizMe series of educational content. Put your knowledge to the test with these 10 questions about the planet. If you would like to brush up on your knowledge about the Jovian system before taking the quiz, we suggest reading this article. Author Chase Clark
This Week in History: March 15-21
MARCH 15, 2020: Comet ATLAS C/2019 Y1 will pass through perihelion at a heliocentric distance of 0.838 AU. This is the fourth known member of a “group” of comets, the first of which appeared in 1988; this, and other comet “groups,” are discussed in a future “Special Topics” presentation. Comet ATLAS has become bright enough …
Comet of the Week: The Great Comet of 1843
Perihelion: 1843 February 27.91, q = 0.006 AU For the first time in “Ice and Stone 2020,” a Kreutz sungrazer is my “Comet of the Week.” Some of the members of this group of comets have been among the brightest and most spectacular comets in all of recorded history, and as a group they are …
Special Topic: Resources in “Small Bodies”
When it comes to their composition and internal structure, there is a wide variety among the asteroids. We know this primarily through two means: the study of the various meteorites that have landed on Earth – the subject of a future “Special Topics” presentation – and examination of their spectrum. Although asteroids do not give …
This Week in History: March 8-14
MARCH 8, 1772: A French amateur astronomer, Jacques Montaigne, discovers a comet that is followed for one month and that reaches 7th magnitude. Over the next 5½ decades the comet is discovered on two subsequent returns, the latter of these being in 1826 by an Austrian army officer, Wilhelm von Biela, for whom it was …
Comet of the Week: 1P/Halley 1981i
Perihelion: 1986 February 9.46, q = 0.587 AU Those of us space-minded people who came of age during the middle decades of the 20th Century learned of Comet Halley and its impending return in 1986, and many of us undoubtedly heard stories of its appearance during its excellent return in 1910; my paternal grandmother, an …
Special Topic: Comet 1P/Halley
To our ancestors of just a few centuries ago, comets were, at best, mysterious objects, very possibly of divine or supernatural origin. When one considers that bright comets could appear anywhere in the nighttime sky, seemingly out of nowhere, and after being visible for a few days or weeks would then disappear, it is little …
This Week in History: March 1-7
MARCH 1, 1705: British astronomer Edmond Halley publishes his calculations of the orbits of the comets of 1531, 1607, and 1682, concluding that they are individual returns of the same comet, and that that comet would return in 1758. His prediction turned out to be correct, and the comet has been named in his honor. …
Comet of the Week: West 1975n
Perihelion: 1976 February 25.22, q = 0.197 AU What I consider to be the best comet I have ever seen was missed by most of the general public. Part of this was due to the fact that it put on its best appearance in the sleepy hours before dawn, but a large part of it …
Special Topic: Fred Whipple’s Comet Model
Once it had become clear that comets are bona fide members of the solar system just as planets and asteroids are, the question then becomes just what their physical nature might be. While they may appear to be fairly large in our nighttime sky, the fact that background stars shine through their tails and their …
Whipple’s Shield protected Giotti
When the Giotti spacecraft launched on its voyage to explore Halley’s Comet in 1985, it was an invention by the son of an Iowa farmer decades earlier that allowed the mission to be successful. The most difficult problem of the mission to overcome was how to ensure that Giotto survived long enough to snap its …
SpaceX Crew Dragon closing in on first launch with astronauts aboard
The United States is drawing closer to launching humans from American soil once again with the arrival of the newest SpaceX Crew Dragon spacecraft at NASA’s Kennedy Space Center in Florida. The capsule is slated to launch with a crew of two NASA astronauts on the Demo-2 mission sometime this spring, marking the first time …
Finalists selected for naming NASA’s next Mars rover
After conducting a nationwide contest where kindergarten through 12th grade students across the United States submitted essays to “Name the Rover,” NASA has selected nine candidate names as finalists to come up with a fitting name for NASA’s Mars 2020 rover. The nine candidate names were selected from more than 28,000 essays submitted since the …
This Week in History: February 23-29
FEBRUARY 23, 1988: David Levy obtains the final visual observation of Comet 1P/Halley during its 1986 return, using the 1.5-meter telescope at Catalina Observatory in Arizona. The comet was located 8.0 AU from the sun and appeared at 17th magnitude. FEBRUARY 24, 1979: The U.S. Defense Department satellite P78-1 is launched from Vandenberg Air Force …
Comet of the Week: Whipple-Fedtke-Tevzadze 1942g
Perihelion: 1943 February 6.72, q = 1.354 AU The name of Fred Whipple is legendary in cometary astronomy. He spent several decades as an astronomer and professor at Harvard University, and is best known for developing what he called the “icy conglomerate” model of a comet’s nucleus (more commonly referred to as the “dirty snowball”) …