You need to upgrade your Flash Player The theme of this blog is not only and obviously space, but in particular “terrestrial worlds”, places that tend to have surfaces on which one could walk or at least attach oneself to. These places sometimes also have other earth-like familiar features such as atmospheres, weather, volcanos, geysers and perhaps, we are finding, even exotic oceans, rivers or lakes that are not necessarily made of familiar materials we are used to here at home. The second theme is imagery. Occasionally I do some retouching of images when needed if an image is incomplete or sometimes “dirty” or noisy. I will attempt to correct image shortcomings based upon other images or well-accepted presumed attributes. When this is done, notes will be offered as to what was added, why and sometimes how it was done. This way no one should ever wonder if something they are looking at is real or photoshop.

Archive for the 'Asteroids' Category

Dawn: Dual Mission to Vesta and Ceres

Sunday, July 15th, 2007

The Dawn mission to the 2 largest asteroids in our Solar System was supposed to have been launched this week, but has been postponed until September of this same year. Apparently due to Dawn’s repeated launching schedule delays it could have interrupted the launching schedule for the Mars Pheonix lander which has a less flexible launch window.

Dawn Dual Mission to Vesta and Ceres

The above images are the best taken thus far of both objects by the Hubble Space Telescope (images not to scale). Vesta appears to be similar to most objects of its type with one exception… We most likely have samples of this body here on Earth as meteorites. It seems the composition of a bunch of meteors known as HED class meteors match that of observations made of Vesta. The theory is that at some point a huge impact took place on Vesta which shattered it into many fragments. Some of these Vesta originating fragments are orbiting the sun in the Asteroid belt to this day while smaller bits of this collision were thrown inward toward the sun (likely through disturbances coming from Jupiter) and some wound up landing here on Earth as meteors. If this turns out to be true, then Vesta would be one of only 5 bodies that we currently have confirmed samples of. Those additional bodies being our own moon, Mars (also through a similar natural meteoric process), Wild 2 and Earth itself.

Ceres on the other hand is the largest Asteroid in the Solar System and for a few days was considered a planet in 2006 until the definition of “planet” was fine tuned a few days later to exclude not only Ceres, but famously Pluto as well. However, an upgrade was in order and Ceres is now officially a Dwarf Planet as it maintains its own spherical shape, orbits the Sun and is not itself a moon of any other body. More interesting than its definitive status in the Solar System is the fact that it is relatively warm, may have a tenuous atmosphere and frost on the surface. Some surface features have also raised many questions about the nature of Ceres such as the dark spot that was imaged in 95 and later disappeared. Then there is the recently observed white spot which has no theoretical identity at all. Hopefully, this may mean that in 2015 we may discover that Ceres is not just another heavily cratered inactive grey body in our Solar System but another enigmatic body like Io and Enceladus that defies preconceived notions of what to expect. Who knows what processes might cause Ceres to be active on any level, but surely we have been surprised before.

Asteroid Surface Images

Friday, May 11th, 2007

The surface of Itokawa

Itokawa (full name 25143 Itokawa) is an Earth crossing type asteroid that was visited by JAXA (Japan Aerospace Exploration Agency) in 2005. It was, and still may be, the first asteroid to be sampled and returned to Earth. To make a long story short, JAXA attempted quite a complicated mission for such a young agency and sent a probe to Itokawa. The plan was for Hayabusa to orbit, land upon, sample a bit of the surface and then return those samples back to Earth for retrieval. Currently, the mission is seriously damaged and operating on 1 of 3 reaction wheels. Additionally, Hayabusa suffered a major solar flare that damaged several battery cells, a rehearsal landing failed, the agency is unsure if any samples actually made it into the return cannister and 2 probes designed to study the surface also failed. Despite all this trouble and serious concern about its ability to even make it back to Earth… in early 2007 Hayabusa began its long questionable trip back home. Should it make it, the sample return cannister should re-enter Earth atmosphere in 2010.

Never surrender!

Wallpaper: Ida and Dactyl

Saturday, December 9th, 2006

Wallpaper: Ida and Dactyl

The main body Ida and the smaller asteroid, or moon, named Dactyl are a part of the family of asteroids found between the orbits of Mars and Jupiter. It is thought that all of these types of asteroids were created by some cataclysmic event which blew apart a larger body, perhaps around 200 to 300 km in diameter. This event (which is theoretical) would also have taken place long after the formation of the solar system and so in celestial terms it is considered a “recent” event. That means had this event not taken place we would have had at least one more dwarf planet in our solar system than we do today.

This flyby was planned as an “extra” for the Galileo mission as they were for the most part “on the way” to its central mission to the Jupiter system. It is thought that Dactyl has a nearly identical composition to Ida and is therefore not thought to be a “captured” moon, but rather one formed somehow from itslef either from a later impact or from the destruction of the originating body.

Wallpaper: Asteroid Eros

Saturday, November 18th, 2006

Wallpaper: Eros

The NEAR spacecraft was designed to visit a few asteroids with the main target being one named Eros. This probe was meant only to orbit this object closely for a year… and it did. But as the probe ran out of feul and for lack of any reason not to, the controllers decided to attempt an impromptu landing on the surface. Even though the probe had not been designed to do this (it lacked landing gear of any kind) they managed to “rest” the probe carefully upon the surface in 2001 and it continued to transmit information back to Earth for more than 2 weeks from the surface.

Image Note: The color of the asteroid itself was enhanced to match that of the close up image included in the upper right. The original full image was black and white.