Talk:Comet Swift–Tuttle

Velocity

Can I see on this page how fast the comet is when touching the earth orbit? Or do I need to calculate myself? I'd like to know because want to know how fast the dust producing the meteors is, when hitting the earth. This could make the text describing the perceived origin of the meteor shower better. JanCK 09:08, 6 July 2007 (UTC)

The dust particles hit Earth at "133,200 mph (60 kilometers per second) relative to the planet", according to Space.com. --1Winston 17:40, 17 July 2007 (UTC)

So, it's about twice the speed of the Earth relative to the sun. Now, I'd like to know whether the comet had the same speed. JanCK 23:50, 17 July 2007 (UTC)

109P was 1.0AU from the Sun on 1992-Nov-25 16:27 UT and at that time the comet had a speed of 63.1 km/s with respect to the Earth. (JPL Horizons option #19 "Heliocentric range" + #22 "Speed wrt Sun & observer") -- Kheider (talk) 11:48, 28 October 2017 (UTC)

Impact?

This article needs revision. It claims both "certain" impact on Earth but also the threat has disappeared. Which is it? -- Kdconod 29 July 2008

Fixed on 10 August 2009 by Richard Arthur Norton

Dead link

During several automated bot runs the following external link was found to be unavailable. Please check if the link is in fact down and fix or remove it in that case!

• http://www.cfa.harvard.edu/iauc/05600/05670.html
  • In 109P/Swift–Tuttle on 2011-05-23 02:06:17, 404 Not Found
  • In 109P/Swift–Tuttle on 2011-05-31 22:22:09, 404 Not Found

--JeffGBot (talk) 22:22, 31 May 2011 (UTC)

Photograph

Because there are no photographs of the comet on Commons, can we upload this photo as Forbes claims it's from NASA? It looks very similar to this photo which NASA credits to Gerald Rhemann, though... cmɢʟee⎆τaʟκ 09:03, 12 August 2016 (UTC)

Conversion of units

Obviously Wikimedia's conversion failed. 1.000.000 miles are 1.610.000 km if you want to round, exactly it are 1.609.344 km. While 1.600.000 km is quite unprecise. --212.186.7.98 (talk) 17:06, 16 August 2018 (UTC)

The appropriate degree of precision is what is in question here. The convert template is flexible, e.g. can give one million miles (1,610,000 km) or one million miles (1,609,344 km), but the prediction isn't precise enough to justify more than 2 significant digits. WolfmanSF (talk) 17:14, 16 August 2018 (UTC)

Osculating orbits

Since all orbits osculate due to perturbations, why are we mentioning it in the lead sentence as if it is some special property that only applies to this object? -- Kheider (talk) 22:44, 23 July 2020 (UTC)

This term is actually in reference to the description of the orbit, not the orbit itself. The "osculating orbit" is the present orbit with no reference to future perturbations. If those perturbations have been analyzed and their future effects incorporated into the description, it is no longer the "osculating orbit" (see Proper orbital elements). WolfmanSF (talk) 03:17, 24 July 2020 (UTC)

The orbit of the comet is not stable over millions of years so I am not sure why you are bringing up proper orbital elements. Again I do not see why we are using jargon that adds nothing to the knowledge of the current (and frequently changing) orbital period. Current is not defined either. If anything I would edit to say "comet with an epoch 1995 orbital period of 133 years." But again, I think the jargon does not help in the lead. -- Kheider (talk) 03:56, 24 July 2020 (UTC)

Perhaps if you check the edit which added the term in question, why it was added will be clearer. WolfmanSF (talk) 04:50, 24 July 2020 (UTC)

Regarding 1036 Ganymed, 0.2421 AU = 36.2 million km = 22.5 million miles; no one considers that a "close approach". Compare that with a distance of ~1.6 million km for Swift–Tuttle in 3044 AD. WolfmanSF (talk) 22:07, 24 July 2020 (UTC)

Depends on semantics, as one could consider all NEOs as making close approaches to Earth. Since Swift–Tuttle is the smaller NEO, it is important to say something to differentiate their orbits. -- Kheider (talk) 22:41, 24 July 2020 (UTC)