Cassini Spacecraft Crosses Saturn's Ring Plane

Explanation: If this is Saturn, where are the rings? When Saturn's "appendages" disappeared in 1612, Galileo did not understand why.

Later that century, it became understood that Saturn's unusual protrusions were rings and that when the Earth crosses the ring plane, the edge-on rings will appear to disappear.

This is because Saturn's rings are confined to a plane many times thinner, in proportion, than a razor blade. In modern times, the robot Cassini spacecraft orbiting Saturn now also crosses Saturn's ring plane.

A series of plane crossing images from 2005 February was dug out of the vast online Cassini raw image archive by interested Spanish amateur Fernando Garcia Navarro. Pictured above, digitally cropped and set in representative colors, is the striking result. Saturn's thin ring plane appears in blue, bands and clouds in Saturn's upper atmosphere appear in gold.

Since Saturn just passed its equinox, today the ring plane is pointed close to the Sun and the rings could not cast the high dark shadows seen across the top of this image, taken back in 2005. Moons appear as bumps in the rings.


Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA

Jupiter and Venus to cross paths

Sometimes, if you're not paying close attention, the sky can play tricks on you.

For the past couple of months, Jupiter has been a prominent object in the southwestern sky just after sunset, what some would call "the evening star." On Feb. 16 there will be a celestial "bait and switch" as Venus replaces Jupiter as the evening star.

Because Earth moves much faster around the sun than Jupiter does, Jupiter appears to move ever-so-slowly from left to right relative to the sun, as seen in the Northern Hemisphere. One can see this effect over the course of a few nights by noting Jupiter's position at the same time each night. Jupiter has been sinking towards the sun night by night over the past two months.

Venus is closer to the sun than the Earth. It passed behind the sun on Jan. 11, from our point of view, and now is moving from right to left relative to the sun towards greatest eastern elongation on Aug. 20 – that's when it'll be farthest out to the side, forming a triangle with Earth and the sun as seen from above, and that's when Venus will appear highest in our sky.

On the evening of Tuesday, Feb. 16, from our vantage point, Jupiter (moving left to right) will pass Venus (moving right to left). The two planets will appear to be separated from each other by an amount equal to the diameter of our moon in the sky.

Even though Venus is much smaller in diameter than Jupiter, it will be very much brighter to the eye because it is much closer to the sun and to Earth than Jupiter.

On Feb. 16, Venus and Jupiter will easily fit in the field of a small telescope. Jupiter will appear more than three times the size of Venus, a brooding giant far beyond brilliant Venus.

Try to follow the action over the next week as the two planets rapidly approach each other. After Feb. 16, Jupiter will be gone behind the sun for the next month, emerging as a "morning star" late in March. Venus gradually gets farther from the sun and more brilliant, reaching greatest eastern elongation on Aug. 20 and greatest brilliancy on Sept. 23, before passing between Earth and sun on Oct. 29.

Los Angeles Marijuana Stores come under increased scrutiny

There are more marijuana stores here than public schools. Signs emblazoned with cannabis plants or green crosses sit next to dry cleaners, gas stations and restaurants.

The dispensaries range from Hollywood-day-spa fabulous to shoddy-looking storefronts with hand-painted billboards. Absolute Herbal Pain Solutions, Grateful Meds, Farmacopeia Organica.

Cannabis advocates claim that more than 800 dispensaries have sprouted here since 2002; some law enforcement officials say it is closer to 1,000. Whatever the real number, everyone agrees it is too high.

And so this, too, is taken for granted: Crackdowns on cannabis clubs will soon come in this city, which has more dispensaries than any other.

For the first time, law enforcement officials in Los Angeles have vowed to prosecute medical marijuana dispensaries that turn a profit, with police officials saying they expect to conduct raids. Their efforts are widely seen as a campaign to sway the City Council into adopting strict regulations after two years of debate.

It appears to be working. Carmen A. Trutanich, the newly elected city attorney, recently persuaded the Council to put aside a proposed ordinance negotiated with medical marijuana supporters for one drafted by his office. The new proposal calls for dispensaries to have renewable permits, submit to criminal record checks, register the names of members with the police and operate on a nonprofit basis. If enacted, it is likely to result in the closing of hundreds of marijuana dispensaries.

Mr. Trutanich argued that state law permits the exchange of marijuana between growers and patients on a nonprofit and noncash basis only. Marijuana advocates say that interpretation would regulate dispensaries out of existence and thwart the will of voters who approved medical cannabis in 1996.

Whatever happens here will be closely watched by law enforcement officials and marijuana advocates across the country who are threading their way through federal laws that still treat marijuana as an illegal drug and state laws that are increasingly allowing medicinal use. Thirteen states have laws supporting medical marijuana, and others are considering new legislation.