|C/1995 O1 Hale-Bopp|
Sizes are best estimates:
Size of nucleus: 40km (25mi.)
Size of Comet Halley nucleus: 20km (12mi.))
Length of Tail: 50-60 million miles in late March
Last visit to inner solar system: 2213 B.C..
Next visit to inner solar system: About 4300 A.D..
Speed of comet at perihelion = 98,000 miles per hour
Speed of comet at aphelion = 250 miles per hour
Distance from Earth (closest approach): 122 million miles
Distance from Sun (closest approach): 85 million miles
Distance of Earth from the Sun: 93 million miles
Composition: "Dirty Snowball" of ice, dust, gas
On its journey towards perihelion Comet Hale-Bopp passed within the gravitational influence of Jupiter. This changed the orbit of the comet and, thereby, the length of time until the next rendevous with our Sun.This is the reason why comet Halebopp last visited us 4300 years ago and the next visit is only 2300 years from now.
Comet Hale-Bopp's twin tails just
stand out more clearly and dramatically than most. One tail (called the
ion tail) is composed of ion gases, is often blue, and it pointed directly
away from the Sun. The other tail (called the dust tail) is white, or yellow-white,
and can curve away from a strict on-axis line. Comet Hale-Bopp has a very
beautiful twin tail presentation.
Dale Ireland of Washington State created this 3D view of Comet Hale-Bopp's orbit which dramatically illustrates the fact that the comet's orbit is almost exactly perpendicular to the ecliptic. The map shows the location of Comet Hale-Bopp and five planets on April 1, 1997 which is the date of perhelion passage. Comet Hale-Bopp enters the map at the bottom left passing near the orbit of Jupiter. It climbs above the ecliptic before turning South, plunging below the ecliptic near the orbital path of the Earth.
Even though the comet will pass near the oribital path of the Earth it will be nowhere near the Earth as we will be on the other side of the Sun in April 1997. It is possible, although not likely, that we could see increase meteor activity in January 1998 when the Earth passes near this same point in space (i.e. our closest approach to Comet Hale-Bopp's orbital path). Although the orbital paths look fairly close in this image, they are sufficiently far apart that the likelihood of increased meteor activity is only slight. Meteor showers are made up of the dust and particles that spew out of comets as they orbit the Sun. When the Earth passes through a comet's orbital path we can see a dramatic increase in meteor activity because we are passing through the dust particle stream. It is much like driving down the freeway with a gravel truck in front of us. The truck is gone from the exact point our car occupies but we still have pebbles that bounce up and hit our windshields.