This Week in History: September 13-19
SEPTEMBER 13, 1959: The then-Soviet Union’s Luna 2 spacecraft impacts the lunar surface slightly to the east of the Mare Imbrium. This was the first human spacecraft to reach the moon and the first spacecraft to impact another object in the solar system. SEPTEMBER 13, 1985: The U.S. Defense Department’s P78-1 satellite is deliberately destroyed …
Comet of the Week: 21P/Giacobini-Zinner 1984e
Perihelion: 1985 September 5.21, q = 1.028 AU The last comet discovered in the 19th Century was found on December 20, 1900, by the French astronomer Michel Giacobini from Nice Observatory, the fifth of twelve comets he discovered between 1896 and 1907. The comet was around 10th magnitude and was followed for two months, with …
Special Topic: Deflection Strategies
A common and persistent theme throughout “Ice and Stone 2020,” and indeed one of the primary reasons the “small bodies” of the solar system are of such high interest in the first place, is the threat they pose to Earth – or, at least, to our civilization and way of life here on Earth – …
Boeing Starliner orbital test flight to ISS targeted for December
As the Boeing team continues to implement hardware and software changes recommended by the joint review team, NASA’s Commercial Crew Program is targeting December for the launch of a second uncrewed test flight of the Boeing CST-100 Starliner spacecraft to the International Space Station. “The Commercial Crew Program currently is targeting no earlier than December …
5 ways families can enjoy astronomy during the pandemic
This is a challenging time for families. Schools across the U.S. are struggling to provide a meaningful online experience. The coronavirus pandemic has cut off or restricted many entertainment options. As an astronomer, I believe a great way for families to fill the void and have a meaningful science experience in the time of COVID-19 …
This Week in History: September 6-12
SEPTEMBER 6, 1618: The German astronomer and mathematician Johannes Kepler observes Comet 1618 I (new style C/1618 Q1) – the first of three “Great Comets” that appeared that year – through a small telescope, the first recorded telescopic observation of a comet. SEPTEMBER 8, 1991: Tom Gehrels with the Spacewatch program in Arizona discovers the …
Comet of the Week: 2I/Borisov I/2019 Q4
Perihelion: 2019 August 8.55, q = 2.007 AU According to our present understanding of how the solar system formed and evolved, all the various comets, including those passing through the inner solar system as well as those in the Kuiper Belt and the Oort Cloud, are the “leftovers” from the planet formation process. Over the …
Special Topic: “Small Bodies” Moons
The “Special Topics” presentation four weeks ago was on the subject of the small moons of the various planets in the solar system. It would seem reasonable to think that the bodies that possess moons don’t stop with the major planets, but that many of the “small bodies” that are the focus of “Ice and …
This Week in History: August 30-September 5
AUGUST 30, 1979: The SOLWIND coronagraph aboard the U.S. Defense Department’s P78-1 satellite records images of a bright comet approaching the sun, and then disintegrating. This comet, the first comet ever to be discovered from space, turned out to be a Kreutz sungrazer, and was the first of several comets discovered by SOLWIND prior to …
Comet of the Week: SOLWIND 1 1979 XI
Perihelion: 1979 August 30.95, q = 0.005 AU The very first comet I ever observed, Comet Tago-Sato-Kosaka 1969g – a previous “Comet of the Week” – was also the first comet ever to be observed from space, an event which took place in mid-January 1970. Since that time many, many comets have been observed by …
Special Topic: The Kuiper Belt
Where the various comets that we see in our skies come from has long been a subject of high scientific interest. The Week 3 “Special Topics” presentation discussed how in the mid-20th Century the Dutch astronomer Jan Oort proposed the existence of the structure that we now call the “Oort Cloud” as being the source …
Blue Origin-led team delivers lunar lander mockup to NASA
The Blue Origin National Team of four US aerospace companies has delivered a full-scale engineering mockup of their proposed human lunar lander to NASA’s Johnson Space Center as part of NASA’s ambitious Artemis Moon program to return astronauts to the lunar surface by 2024. The Artemis Human Landing System (HLS) lander has been set up …
Four astronomical discoveries from ancient Greece
The Histories by Herodotus (484BC to 425BC) offers a remarkable window into the world as it was known to the ancient Greeks in the mid-fifth century BC. Almost as interesting as what they knew, however, is what they did not know. This sets the baseline for the remarkable advances in their understanding over the next …
This Week in History: August 23-29
AUGUST 23, 1862: The comet now known as Comet 109P/Swift-Tuttle passes through perihelion at a heliocentric distance of 0.963 AU. The comet had been discovered the previous month independently by Lewis Swift and Horace Tuttle, and became a conspicuous naked-eye object. It is the parent comet of the Perseid meteor shower and is a future …
Comet of the Week: Messier C/1769 P1
Perihelion: 1769 October 8.12, q = 0.123 AU As discussed in the “Special Topics” presentation on that object, in the early 18th Century the British astronomer Edmond Halley predicted that the comet that now bears his name would be returning around 1758. As that time approached several astronomers became involved in the effort to search …
Special Topic: Interplanetary Dust
The “Special Topics” presentation two weeks ago pointed out that the term “small bodies” of the solar system generally refers to objects like comets and asteroids, although that particular presentation discussed another class of such objects, i.e., the small moons of the planets. To carry the term “small bodies” to an extreme, we could examine …
SpaceX launch of Crew-1 mission set for Oct. 23
NASA is targeting no earlier than Oct. 23 for the first operational flight of the commercial SpaceX Crew Dragon spacecraft with astronauts launched by a Falcon 9 rocket to the International Space Station as part of the agency’s Commercial Crew Program – following the recent conclusion of the historic Demo-2 test flight to the station …
This Week in History: August 16-22
AUGUST 16, 1898: DeLisle Stewart at Harvard College Observatory’s Boyden Station in Arequipa, Peru, takes photographs on which Saturn’s outer moon Phoebe is discovered, although the images of Phoebe were not noticed until the following March by William Pickering. Phoebe was the first planetary moon to be discovered via photography, and it and other small …
Comet of the Week: Levy 1990c
Perihelion: 1990 October 24.68, q = 0.939 AU I’ve commented in previous “Ice and Stone 2020” presentations that I spent several hundred hours unsuccessfully hunting for new comets before giving up that endeavor, and then accidentally discovered the comet that bears my name three years later. I did the bulk of my hunting during the …
Special Topic: The “Building Blocks” of Life
The “Special Topics” presentation two weeks ago discussed the possibility that signs of life might exist within certain meteorites that have been found to have come from Mars, although it did so partially within the overall context of “are we alone?” Another part of that discussion revolves around how life on Earth – and, hopefully, …