Globular Cluster



Of three objects prominent in this thoughtful telescopic image, a view toward the stealthy constellation Lynx, two (the spiky ones) are nearby stars. The third is the remote globular star cluster NGC 2419, at distance of nearly 300,000 light-years. NGC 2419 is sometimes called "the Intergalactic Wanderer", an appropriate title considering that the distance to the Milky Way's satellite galaxy, the Large Magellanic Cloud, is only about 160,000 light-years. Roughly similar to other large globular star clusters like Omega Centauri, NGC 2419 is itself intrinsically bright, but appears faint because it is so far away. NGC 2419 may really have an extragalactic origin as, for example, the remains of a small galaxy captured and disrupted by the Milky Way. But its extreme distance makes it difficult to study and compare its properties with other globular clusters that roam the halo of our Milky Way galaxy.

Largest Full Moon of 2009



A larger moon will not be seen this year. This past weekend, the largest full Moon of 2009 could be seen from almost any clear location on planet Earth at night. The large angular extent of the full Moon was caused by the Moon being unusually close to Earth during its full phase. Because the Moon circles the Earth in an elliptical orbit, its angular size depends on how close the Moon is to closest approach (perigee) or farthest distance (apogee). Even so, the Moon's was only about 15 percent larger in area and brightness than a more typical full Moon. In this image, a dramatically positioned Moon is seen rising above the Alps from Breil-sur-Roya in the southeast of France. Taken with an ordinary digital camera but extraordinary timing, the image also captured a crossing jet plane. The last full Moon, in 2008 December, was the largest full moon of 2008.

Planetary Nebula



NGC 2818 is a beautiful planetary nebula, the gaseous shroud of a dying sun-like star. It could well offer a glimpse of the future that awaits our own Sun after spending another 5 billion years or so steadily using up hydrogen at its core, and then finally helium, as fuel for nuclear fusion. Curiously, NGC 2818 seems to lie within a sparse open star cluster, NGC 2818A, that is some 10,000 light-years distant toward the southern constellation Pyxis (Compass). Since open star clusters disperse after only a few hundred million years, this one must be exceptionally old to have one of its member stars evolve to the planetary nebula stage. At the distance of the star cluster, planetary nebula NGC 2818 would be about 4 light-years across. The Hubble image is a composite of exposures through narrow-band filters, presenting emission from nitrogen, hydrogen, and oxygen atoms in the nebula as red, green, and blue hues.