Van Flandern's theory had predicted that Comet Shoemaker-Levy had once been such a family of cemetery satellites that was disrupted by previous encounters with Jupiter's gravitational attraction, and which was subsequently strung out into a cemetery train, much as we encounter with the annual Taurid and Orionid meteor streams
. In fact, all such meteor showers are residual of cemetery trails that now only follow ephemerid paths, having typically lost the gaseous components that once made them shine for an awed mankind.
There is an increased risk that Earth will be hit by an asteroid from a meteor stream
known as the Taurids, Czech astronomers (https://www.afp.com/en/news/2265/czech-scientists-see-growing-risk-asteroid-hitting-earth) said on Tuesday.
(A radiant's position among the constellations is the sum of both the meteor stream
's motion and Earth's motion.)
Unusual in being associated with an asteroid--(3200) Phaethon --rather than a comet, the shower has grown in intensity since the 1980s as a result of the meteor stream
orbit being dragged gradually outwards across that of the Earth.
The Kappa Cygnid meteor stream
peaked at the weekend and may emit bright fireballs.
"T people of GAaAaAeA bekli Tepe appear to have had a special interest in t Taurid meteor stream
, the same meteor stream
that is proposed as responsible for the (http://news.nationalgeographic.com/news/2013/09/130910-comet-impact-mammoths-climate-younger-dryas-quebec-science/) Younger-Dryas event," the study said.
Only one major meteor stream
, the one shed by Halley's Comet, intersects Earth's orbit In two places with both of the resulting showers being visible at night.
The Leonids are active each year between November 15 and 20, with a regular annual maximum close to the time of Earth's closest approach to the meteor stream
's descending node at solar longitude(2000.0) = 235.4[degrees], usually on November 17-18.
This was based on calculations that indicated the meteor stream
shifted closer to Earth's orbit by Jupiter this year.
That evening, astronomers predict that Earth will pass through a rich part of the irregular and surprise-filled Draconid meteor stream
. If you're in North America, the predicted peak will occur in the afternoon, so you'll be looking for the tail-off of the expected outburst--or perhaps you'll benefit from an error of just a few hours in when we're supposed to meet the bulk of the Draconids.
The asteroid thus receives a regular blast of heat from the Sun which boils jets of dust into the Geminid meteor stream
After midnight, the Earth is running into the meteor stream
As the Earth passes through the meteor stream
every year, the dust particles burn in the Earth's upper atmosphere, causing a radiant glow.
Drawing on observations of another very-long-period meteor stream
(the Alpha Monocerotids), Jenniskens showed that the Aurigid outbursts of 1935, 1986, and 1994 all arose when Earth passed through this one lengthy debris trail.
Every 33 years, when the comet passes through the inner solar system, it sheds a new filament of debris, adding to the general meteor stream
. When Earth encounters one of these dense new filaments (which haven't yet had time to disperse very much), we can get a very strong but short-lived meteor display.