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Comets, Asteroids, Meteors


Comet Shoemaker-Levy 9

hubble/sl9.jpg


Comet Hyakutake
 


Comet Hale-Bopp


Comet Linear A2

../verschie/comet.jpg
 

I hope you can identify the faint comet Linear A2 in the 4 images of West-Pegasus taken in July 2001.

In the first photo, 7-14-01, Enif is the bright star in the upper right.  In the sky it would be the brightest of all the ones in the image, but the photographic emulsion makes other stars appear just as bright.
There are two stars straight down from Enif, making an acute triangle (another way of finding Enif).
To the right of Enif is a triple.
Comet Linear A2 is smack in the middle of the photo.

The photos from 7-15 and 7-16 still have the acute Enif triangle and the triple on the right.  The comet is still close to the center of the photo, but harder to see.  (You also see some wispy clouds on the 7-15).

The photo from 7-17 is too long exposed, thus star trails (I used a simple tripod).  The comet is right of center, Enif to its lower right (your star is [invisibly] below Enif but still in the photo).  The long trail is an airplane's lights.

All photos were shot from Scottsbluff, Nebraska.


Comet Ikeya-Zhang
../verschie/koji_ikeya_zhang.jpg
Photo by Koji Oshima, Japan.

Asteroids
 

Subject: Asteroid XF 11 animation
 

Subject: Spacecraft NEAR Shoemaker near Asteroid Eros

>Since Eros is not round, I imagine maintaining an orbit
>would be quite a feat, but probably made more managable by
>the slow speed required to orbit such a relatively small
>mass.

One can show that at large enough distances the gravitational force can be seen as emanating from the asteroid's center of mass.  NEAR's orbit is thus not endangered.  But they just have to monitor carefully its orbit because any deviations from a true Kepler orbit (closed ellipse) give clues about Eros' mass distributions.

Asteroid Eros' density: 2.4 grams/cm^3; mass: about 5 x 10^15 kg.

NEAR's speed is amazing now: 3 feet per second, that's like strolling down main street.  Trajectory.
 

Subject: NASA's Asteroid pages , fact sheet
 
 
Close ups of asteroids
(all to scale)
433 Eros (NEAR Shoemaker; was in orbit around Eros from 2-14-2000 to 2-12-2001).  Eastern hemisphere on top, Western below.  NEAR is the first spacecraft that landed on an asteroid, February 12, 2001. ../verschie/asteroid_mathilde.gif 253 Mathilde (NEAR Shoemaker fly-by; June 27, 1997).
951 Gaspra (Galileo fly-by; October 29, 1991). 243 Ida and its moon Dactyl (Galileo fly-by; August 28 1993).  An asteroid with a moon was an extraordinary discovery.  Using Kepler 3, Ida's mass 100 x 10^15 kg is probably the most accurately determined of all asteroids.

Meteors

Leonid Meteor Shower, November 19, 2001
../verschie/koji_leonids.jpg
Photo by Koji Oshima, Japan.

To my WNCC Astronomy home page .