Saturn Rings-Calonnec.jpg
This is a view of crescent Saturn, based on an image from the Cassini spacecraft taken on March 12, 2014.
(NASA/JPL-Caltech/Space Science Institute/Stephane Calonnec)
Keep an eye on the sky this week - for an opportunity to see two planets.
Mars reached its opposition on May 22. Now, it is Saturn's turn. The ringed planet is opposite the sun on Friday. As with Mars, it rises just after sunset and is in the sky all night.
Mars just crossed the border into the constellation Libra, and Saturn is in Ophiuchus. Sandwiched between the two planets is Scorpius, the scorpion. Only the upper portion of Scorpius is above the horizon in the early evening. The heart of the scorpion, Antares, is visible below the two planets.
To view these planets, go outside about 10 p.m. and face southeast. The planets are low in the sky. Mars is quite bright and should be easily visible. Look for Saturn and Antares below and to the left of Mars.
Mars and Saturn are visible low in the southeast sky about 10 p.m.
Mars is closest to Earth on Memorial Day. It is a cosmic concurrence that the planet named for the Greco-Roman god of war is so near on the day that we remember those who have died in military service to our country. Astronomers named a broad flat plain near the Martian equator, Elysium Planitia. This is a reference to the Greeks' Elysian Fields, a mythical place that heroes would remain after death. On Monday, the distance from the Earth to the red planet will be 47 million miles.
Saturn's turn in the spotlight comes when it reaches opposition next Friday. This is also when it is closest to us - at a distance of 838 million miles. An interesting coincidence: Despite their difference in dimension, both Mars and Saturn now appear to be the same size. Saturn, in reality, is much larger - so large that you could fit more than 5,000 Mars-sized planets inside Saturn! But because of its greater distance, the disk of Saturn (not counting its rings) will appear the same size as Mars in a telescope.
VIEWING THE RINGS
Although it is not the only planet with rings, Saturn is famous for its set. They are enormous, with a diameter of more than 200,000 miles. Even a small telescope will show you the rings - a magnification of only 20 to 40 power is needed.
When you view the rings, notice that they are almost wide open (as opposed to edge on). Saturn is now in the part of its orbit where it is tilting its northern hemisphere toward us, so we have a nice view of its rings. This is good preview for next year, when Saturn's tilt (with respect to us) is at maximum.
PLUTO IS FIRST CLASS
Meanwhile, Pluto - the largest dwarf planet - is about to go first class with the U.S. Postal Service. On Tuesday, a postage stamp featuring Pluto will be released during the World Stamp Show at the Jacob Javits Convention Center in New York. The stamps will feature both the dwarf planet and the New Horzions spacecraft.
The new stamps show an artists' rendering of the New Horizons spacecraft and an enhanced color image of Pluto taken by the spacecraft near its closest approach.
When Pluto was last featured on a stamp in 1991, it had not yet been visited by a spacecraft and so an artist's rendition was used. One of those 1991 stamps was put aboard the New Horizons spacecraft and traveled to Pluto for the historic flyby.
The Postal Service is also releasing a set of new stamps that feature the eight major planets in the solar system. Some show the planets' "true color" - what one might see in visible light; others use "false colors," based on imaging data to emphasize features not visible to the human eye.
Kevin D. Conod is the planetarium manager and astronomer at the Newark Museum's Dreyfuss Planetarium. For updates on the night sky, call the Newark Skyline at (973) 596-6529.