In early 1986, Halley's
Comet visited Earth's neighborhood again.
Here are several pictures taken in March over a period of 5 days.
This photograph was taken on 19
March 1986, from 02:30-03:00 PST.
It shows a mixture of objects at different distances. At the lower left, a
satellite's
flickering trail is visible. To its right, a fuzzy ball is the image of M-55, a
Globular Cluster
thousands of light years away. Most stars visible in the photo lie between the
Earth
and M-55, while Halley's Comet was within the orbit of Mars when this photo was taken.
This is a composite photograph is
made from three exposures taken on 18-20 March 1986. Each was taken from 02:30-03:00 PST,
showing the movement of the comet relative to the background stars. You can also see
changes in the size and shape of the comet's coma and tail.
This image is a
"negative", in which black and white have been reversed. This helps
you see the stars and comet positions more accurately than a
"positive" image with white stars. To see a larger positive image, click
here.
Here
you can see the three comet images shown above, together with a fourth image
taken two days after the other three. Clouds prevented photographing the comet
on one day, resulting in the missing comet image.
The constellation Sagittarius (also
known as The Teapot) is outlined to help you locate the position of Halley's
Comet relative to the background stars. The asterism known as the The Teaspoon
is also visible in the upper left.
Click
here
or on the image to see a larger view that includes constellation lines.
For larger images without
constellation lines, you may choose widths of 400,
800, 1024,
1280 or 1600
pixels. They make great backgrounds for your desktop!
