What's in a name?
Thursday, March 29, 2012
Planet ... the very name gives indication of what it does. Ancient astronomers recognized that there were "stars" that did not remain fixed in one position. They roamed, or wandered, and could be seen in different places at different times of the year.
In fact, since Venus appeared in the morning and evening skies, it was once thought that it was in fact two separate planets.
That is what the word "planet" means, a wanderer.
We have been treated to a fine example of planetary wandering for the past few weeks.
We have watched as Venus, Jupiter, Mars and now Saturn demonstrated this wandering characteristic.
The moon has even gotten into the act and joined up with these "wanderers" over the past weeks, and even though it is drawing to a close, the show is not yet over.
We have watched as Venus, the second planet out from the sun, has risen higher, joined with and now passed Jupiter and is continuing on its outward journey.
Next week, from April 1 through April 5, Venus will play an April Fool's joke on all of us. It will masquerade as a member of the Pleiades star cluster.
To view this little trick, you don't even need a particularly dark sky, just a good view to the west and a good pair of binoculars.
Start viewing on the evening of Sunday, April 1.
The tiny Pleiades star cluster is located just to the lower left of the "V" shaped constellation of Taurus, the Bull, and just above the very bright Venus.
Both of them will be in the same field of binocular view.
Go out at about an hour after sunset each evening and watch as Venus creeps up closer to the dipper-shaped cluster and on April 2 and 3 will actually look like a member star of the cluster.
Just remember, they are not really close, both of them just happen to be along the same line of sight from Earth.
In reality, Venus is 26 million miles away at its closest and 258 million miles away at its farthest point, whereas the Pleiades cluster is estimated at between 434 and 446 light years away. Keep in mind that a light year is about six trillion miles.
The travels of Venus are not yet over. The bright planet reached its greatest elongation from the sun in late March and will now start back down toward the western horizon. It will, however, be visible as an evening object until early May.
After traveling through the Pleiades, Venus will continue on to visit the star Aldebaran, the brightest star in Taurus, the Bull from April 7-10; will meet up with the moon again on April 24, and go as far as visiting the star El Nath in the constellation Auriga, the Charioteer in early May.
That will be great because there are several very nice star clusters in that area that can be easily seen with binoculars.
SKY WATCH: First quarter moon, March 30; Venus in the Pleiades star cluster April 1-3; a full moon, Saturn, and Spica will be close on April 6, best viewed after 11 p.m. MDT; Mars continues getting closer to Regulus, the brightest star in Leo, the Lion.
It will keep getting closer until April 12, when the red planet ends its current retrograde movement and resumes it regular west to east motion against the background stars.
The almost-full moon will join Mars and Regulus on the evening of April 3.
NEXT WEEK: More astronomical blathering.