I was just getting ready to begin updates on the various spacecraft around and on Mars when this image of a hole on Mars showed up on the Astronomy Picture of the Day site. The absolute darkness of the region reminded me of those black dot bad pixels in older Viking images. However, it is rather clear that this black dot is much larger than a single pixel!

The image was taken with the HiRISE camera on the Mars Reconnaisance Orbiter spacecraft and it appears to be the opening to a fairly deep cave. So deep that no sunlight reaches the bottom. The cave is located on the flank of the volcano Arsia Mons, the southernmost peak on the Tharsis plateau.

It turns out, this feature is not unique. In a paper presented at the 38th Lunar and Planetary Science Conference this past March by scientists from the US Geological Survey, Northern Arizona University, and Arizona State University (G. E. Cushing, T. N. Titus, J. J. Wynne, and P. R. Christensen), have identified seven such regions that may be skylight entrances to deep, underground caves on Arsia Mons.

In their paper they give several reasons for thinking these are cave entrances instead of just some really dark patch of ground. First, they are located in regions near collapse pits, indicating "open" underground regions. Second, they are not, themselves, collapse pits, or craters since they do not have visible floors/walls, nor do they have rims or the spray-pattern of debris associated with craters. Third is their thermal properties.

See, these areas have also been images by the THEMIS instrument on Mars Odyssey which can measure the temperature of the martian surface. These dark areas are warmer than shadowed areas but cooler than the surrounding ground during the day, but warmer than the surrounding ground at night implying they are underground regions that keep a relatively constant temperature, much like caves here on Earth.

What makes caves on Mars really interesting is that they would be "safe zones" for microbial life. Since the weak magnetic field and thin atmosphere allow all manner of UV and high-energy cosmic ray radiation to hit the surface, all life as we know it would be killed off rather quickly. Deep caves would block all of that radiation; and these skylights present ways into these underground caves.

Time to send in the spelunkers! Any takers?

Welcome to the new and improved International MarsWatch! After years of running this site, I finally realized that I needed the help of someone with far better web skills than I. Fortunately, there is considerable talent in the students at Rowan's Computer Science department, and so we now have this brand new site. Oh, if you don't like the color scheme, blame me—that was all my doing. I'm not entirely sure I like it yet, but we'll see. Supposedly changing that will not be overly difficult.

The project started with trying to create a way to make image submission easier. Most images were uploaded the last time around via e-mail submissions directly to me. It was great being the first to see them, but as the season progressed, it became time consuming to handle it all. The solution designed was great, but required other changes, which required other changes…

This new site now has an automated image submission system. Members can upload images, and even include a text description should they like (it should even handle "international" characters correctly). There is still a review process I'll have to go through, just to keep any "inappropriate" images from showing up here.

The rest of the site features have been ported over including the MarsView program, basic opposition information, Mars-related links, and the Newsletter archive. Just poke around through the links in the left-hand menu.

The biggest change is this blog. Instead of trying to put out a monthly newsletter with some of the latest Mars info and news, I will be doing entries here once or twice a week. This way, the news will be more current, and I can even use this area to review some of the current Mars research from the scientific journals. I'll still try to send out a Newsletter, but it will be devoted to Mars ephemerides, and a summary of, say, the last few blog entries.

One other thing I'd like to do here is help maintain the bridge between the amateur and professional Mars observers. As the professionals get their observing time awards, it would be nice if they'd pass them along so that others can perform coordinated observations. Once again, the goal of the MarsWatch is planet-wide imaging throughout the opposition.