Asteroids in the Zodiac

[James Strom]

I wonder if anybody has noticed this before; although Neptune was discovered in Aquarius, it was recovered the next year on May 6, 1847 at 00° 11'.

https://articles.adsabs.harvard.edu/cgi ... lassic=YES

[James Strom]

Comet_Seki-Lines.jpg (136.08 KiB) Viewed 426 times

1962/02/04 Great Comet of 1962 discovered by Richard D. Lines and Tsutomu Seki.

1962/04/01 Perihelion of Great Comet of 1962.

The comet was discovered independently by Richard D. Lines and Tsutomu Seki on 4 February 1962. The comet then was located near ζ Puppis and its apparent magnitude was estimated by the Lowell Observatory to be 8 two days later. At the end of February and early March the comet became visible by naked eye, as it crossed the constellations of Eridanus and Cetus. The comet brightened rapidly and by 27 March its magnitude was estimated to be 0 to -1. The comet reached its perihelion on 1 April 1962, at a distance of about 4 million kilometers from the Sun, and although it should have been bright enough, no daylight observations were reported.

From May 27th to June 7th 1962 all of the first four asteroids discovered were in their night homes with Pallas even in its quintan!

1962/05/27-00:00

00° 00' Vesta
24° 57' Ceres
20° 18' Juno
09° 57' Pallas

1962/06/07-20:00

05° 04' Vesta
00° 00' Ceres
27° 05' Juno
15° 17' Pallas

800px-Swift-Tuttle_Comet_Particles.jpg (62.71 KiB) Viewed 424 times

In 1980 these asteroids were at home again.

1980/07/18-16:00

14° 21' Vesta
22° 27' Ceres
00° 22' Pallas

1980/08/07-03:00

22° 46' Vesta
00° 00' Ceres
03° 49' Pallas

Vesta was in its night home quintan of Pyxis most of the time.

The Perseid meteor shower is caused by debris from Comet Swift-Tuttle. It usually peaks around August 9-14. In 1980 it was particularly spectacular.

1980/08/12-05:00 Perseids at maximum.

Comet Swift–Tuttle is by far the largest near-Earth object (Apollo or Aten asteroid or short-period comet) to cross Earth's orbit and make repeated close approaches to Earth. With a relative velocity of 60 km/s, an Earth impact would have an estimated energy of ~27 times that of the Cretaceous–Paleogene impactor. The comet has been described as "the single most dangerous object known to humanity". In 1996, the long-term possibility of Comet Swift–Tuttle impacting Earth was compared to 433 Eros and about 3000 other kilometer-sized objects of concern.

[James Strom]

Due to Ceres and Pallas being near each other and having almost exactly the same orbital periods they will very often both be in their night homes simultaneously, about once every four to five years. Occasionally Vesta will also be be in her night abode as well. This cosmic coincidence will not last much longer. In fact, there will only be one more time that all three of the biggest asteroids will reside in their domiciles at once; in 2031. After that there will be a very, very long wait until this happens again (around the year 3500).

What follows are descriptions of all the times that they have occurred since these asteroids have been discovered. A remarkable feature of this is how often a comet appears right around then.

Comet_of_1811.jpg (16.95 KiB) Viewed 466 times

1810/04/09-14:00

10° 17' Vesta
00° 00' Ceres
02° 31' Pallas

1810/06/02-06:00

29° 10' Vesta
22° 00' Ceres
00° 00' Pallas

All three asteroids fully traverse their quintans. This one was of a particularly long duration, as was the comet that followed.

1811/03/25 Great Comet of 1811 discovered by Honoré Flaugergues.

1811/04/11 Great Comet of 1811 recovered by Jean-Louis Pons and Franz Xavier von Zach.

At the midpoint of War and Peace, Tolstoy describes the character of Pierre observing this "enormous and brilliant comet [...] which was said to portend all kinds of woes and the end of the world".: 363  The comet was popularly thought to have portended Napoleon's invasion of Russia (even being referred to as "Napoleon's Comet") and the War of 1812, among other events.

The_story_of_the_comets_-_Encke's_Comet,_Nov._30,_1828.jpg (44.25 KiB) Viewed 457 times

At the time Uranus entered Aquarius the three largest asteroids again were all in their night homes.

1828/06/06-20:00

21° 46' Vesta
00° 00' Ceres
00° 19' Pallas

1828/06/25-20:00

00° 00' Vesta
07° 44' Ceres
07° 17' Pallas

Ceres was in its quintan of Auriga almost the whole time.

The periodicity of Comet Encke was only recently discovered at this time. The 1829 appearance was its brightest ever recorded.

Comet Encke is believed to be the originator of several related meteor showers known as the Taurids (which are encountered as the Northern and Southern Taurids across November, and the Beta Taurids in late June and early July). A shower has similarly been reported affecting Mercury.

800px-Smyth_The_Great_Comet_of_1843.jpg (110.63 KiB) Viewed 454 times

Fifteen years later the three biggest asteroids were back home again.

1842/06/30-13:00

00° 00' Vesta
20° 35' Ceres
19° 49' Pallas

1842/07/23-07:00

09° 50' Vesta
00° 00' Ceres
29° 36' Pallas

1843/02/05 The Great Comet of 1843 is discovered.

The Great Comet of 1843 developed an extremely long tail during and after its perihelion passage. At over two astronomical units in length, it was the longest known cometary tail until measurements in 1996 showed that Comet Hyakutake's tail was almost twice as long. There is a painting in the National Maritime Museum that was created by astronomer Charles Piazzi Smyth with the purpose of showing the overall brightness and size of the tail of the comet.

Great_Comet_of_1882.jpg (94.66 KiB) Viewed 452 times

This is probably the best of them all. The first four asteroids discovered as well as the tenth, which is the fourth most massive, are all in their night homes!

1879/05/01-02:00

21° 13' Vesta
05° 38' Ceres
00° 00' Pallas

1879/05/06-23:00

23° 13' Vesta
08° 06' Ceres
02° 36' Pallas
00° 00' Hygiea

1879/05/12-13:00

25° 11' Vesta
10° 22' Ceres
00° 00' Juno
05° 06' Pallas
01° 43' Hygiea

1879/05/25-09:00

00° 00' Vesta
15° 45' Ceres
07° 35' Juno
10° 56' Pallas
05° 28' Hygiea

It now seems that the Great Comets of 1843, 1880, and 1882 were all part of the same one that broke up earlier.

1882/09/07-16:00 Great Comet of 1882 discovered by W.H. Finlay.

Studies of the orbit of the comet showed that the Great Comet of 1882 was moving on an almost identical path to previous great comets seen in C/1843 D1 and C/1880 C1. These comets had also suddenly appeared in the morning sky and had passed extremely close to the Sun at perihelion. One suggestion was that all three were in fact the same comet, with an orbital period that was being drastically shortened at each perihelion passage. However, studies showed this to be untenable, as the orbital period of this comet is 772 ± 3 years and the others are 600–800 years.

Heinrich Kreutz studied the orbits of the three great comets, and developed the idea that the three comets were fragments of a much larger progenitor comet which had broken up at an earlier perihelion passage. The fragmentation of the Great Comet of 1882 itself demonstrated that this was plausible. It is now thought that the Great Comet of 1882 is a fragment of X/1106 C1, and that Comet du Toit (C/1945 X1) and Comet Ikeya–Seki (C/1965 S1) are two of its sister fragments. The comet of 371 BC may have been the source of the group.

Comet_1910_A1.jpg (13.08 KiB) Viewed 439 times

1910 was quite a year for comets.

1910/01/17 Great Daylight Comet of 1910 studied by Robert T.A. Innes.
1910/01/17 Perihelion of Great Daylight Comet of 1910.

The year 1910 saw considerable media interest in the predicted return of Halley's Comet, which reached perihelion on April 20. The appearance of the Daylight Comet several months earlier therefore came as something of a surprise, and made an extremely strong impression on an expectant public; when Halley's Comet returned again in 1986, many older people's accounts of having seen it in 1910 clearly referred to the Daylight Comet instead.

Halley's_Comet_-_May_29_1910.jpg (67.12 KiB) Viewed 437 times

1910/04/20 Perihelion of Halley's Comet.
1910/05/19 Earth passes through the tail of Halley's Comet.

The 1910 approach, which came into naked-eye view around 10 April and came to perihelion on 20 April, was notable for several reasons: it was the first approach of which photographs exist, and the first for which spectroscopic data were obtained. Furthermore, the comet made a relatively close approach of 0.15 au, making it a spectacular sight. Indeed, on 19 May, Earth actually passed through the tail of the comet. One of the substances discovered in the tail by spectroscopic analysis was the toxic gas cyanogen, which led press to misquote the astronomer Camille Flammarion by stating he claimed that, when Earth passed through the tail, the gas "would impregnate the atmosphere and possibly snuff out all life on the planet". Despite reassurances from scientists that the gas would not inflict harm on Earth, the damage had already been done with members of the public panic buying gas masks and quack "anti-comet pills".

Because its orbit comes close to Earth's in two places, Halley is associated with two meteor showers: the Eta Aquariids in early May, and the Orionids in late October.

1911/06/24-02:00

00° 00' Vesta
15° 03' Ceres
04° 51' Pallas

1911/06/28 The Martian Nakhla meteorite falls in Egypt.

1911/07/30 Hiram Bingham discovers Machu Picchu.

1911/07/30-17:00

15° 53' Vesta
00° 00' Ceres
16° 55' Pallas

Pallas was in its night home quintan of Lepus in the later half.

[Noel Eastwood]

Very very interesting James, thanks.

[James Strom]

Leonids-1833.jpg (543.74 KiB) Viewed 418 times

The Leonids are a prolific annual meteor shower associated with the comet Tempel–Tuttle, and are also known for their spectacular meteor storms that occur about every 33 years.

Although it has been suggested the Leonid meteor shower and storms have been noted in ancient times, it was the meteor storm of November 12–13, 1833 that broke into people's modern-day awareness. One estimate of the peak rate is over one hundred thousand meteors an hour, while another, done as the storm abated, estimated in excess of 240,000 meteors during the nine hours of the storm, over the entire region of North America east of the Rocky Mountains.

Leonid storms gave birth to the term meteor shower when it was first realised that, during the November 1833 storm, the meteors radiated from near the star Gamma Leonis.

27° 16' Gamma Leonis
26° 08' Ceres
20° 07' Pallas

[Noel Eastwood]

Thanks, James, another interesting historical piece.

[James Strom]

Comet_Temple-Tuttle_u4jm0404r.fits.gz_sci.jpg (66 KiB) Viewed 178 times

In a few years the three big asteroids, Ceres, Pallas, and Vesta, will all be in their homes at the same time for the last time in over a thousand years. And Comet Tempel-Tuttle will be back again to give us more meteor showers.

2031/05/20 Comet 55P/Tempel-Tuttle comes to perihelion.

2031/05/30-15:00

04° 49' Vesta
23° 49' Ceres
00° 00' Pallas

2031/06/14-02:00

11° 00' Vesta
00° 00' Ceres
05° 28' Pallas

Leonid_meteor_shower_as_seen_from_space_(1997).jpg (40.89 KiB) Viewed 178 times

[Noel Eastwood]

Now that's something to look forward to!