SEPTEMBER ASTRONOMY PICTURES

Here's a composite view of Pluto taken by the New Horizons probe on July 14th. Most of the closeup pictures taken then are still stored on the spacecraft and are only now being sent back slowly.

Above, a detail of Pluto's surface. The smallest details are maybe a kilometer and a half wide.

Above, a solar prominence. Thanks to the old Voyager spacecraft which is now in deep space between us and Alpha Centauri we now know what happens to these ejections when they leave the Solar System.

The ejecta that faces the center of the galaxy is stopped when it collides with intense radiation coming our way from other stars. The interface consists of a crescent-shaped cloud of magnetic bubbles. It's speculated that this cloud shields the Solar System from lethal radiation emanating from the galactic center.

A study of the surface of Saturn's moon Enceladus now reveals that the plates of ice in this hemisphere are all moving in the same direction, something which reinforces the case for global underground seas.

NASA's going to announce a major finding about Mars on Monday, but they're keeping their cards close to the vest until then. The news media is speculating that it might have something to do with water being discovered on that planet; not billion year-old dry river beds but fresh, currently existing water. Actually, if it's there it's probably just enough to temporarily wet the ground in a few places...but that certainly qualifies as news.

On the other hand...you don't think they found evidence of old life, do you? Naw...that would be too good to be true.

[Update, Tuesday: Yep! It was water, and water only. Seasonal changes in the water patterns on hills confirm its existence. The water doesn't last long, though. It evaporates on its way down the slopes. A chemical in the soil allows the water to stay liquid for a time, even in the cold Martian air.]

[Another Update 10/8/2015: Small pockets of liquid water have been found on Pluto! Most likely it came up to the surface from an underground source, indicating internal heat within the planetoid.]

NEW ASTRONOMY PICTURES: JANUARY 2015

Above, a kilometer high cliff on Comet Churyumov-Gerasimenko. The largest boulders at the cliff bottom are about 20 meters wide. The photo was taken a few weeks ago by the Rosetta orbiter.

Here's an interesting photo (above). It's a composite picture of our galaxy's core taken by Hubble and the Spitzer X-ray telescope. The white splotch on the lower right is a star cluster surrounding Sagittarius A, the super massive black hole at the galactic center.

In case the wide photo showing the Sagittarius A cluster is obscured by my sidebar, here's (above) an unencumbered enlargement. There's a nearby cluster on the upper left, which is puzzling. How did it escape being ripped apart by Sag. A? And what are those rake marks on the upper right?

Here's (above) an old friend, the M16 star nursery taken by Hubble. You probably saw the 20 year old photo which is considered by many to have been Hubble's greatest achievement. This latest picture benefits from a wider field and a higher res.

Above, a nebula so close that it can be seen as a small fuzzy patch with the naked eye: The Great Nebula in Orion.  It's the same nebula that contains the famous horse head, though I don't see it here. The image is a false color infrared composite taken by the Earth orbiting WISE observatory. Infrared allows us to see through dense clouds that previously obscured what we wanted to see. Boy, we sure got our money's worth with these orbiting telescopes!