Tuesday, May 27, 2008

Mars Phoenix Lander Descending

Credit: NASA/JPL-Caltech/University of Arizona

This is a very unique and interesting photograph. There are two versions of this photo available from NASA; one with no background and this one with. I've chosen this particular image because it has a better resolution with respect to seeing all of the spacecraft, the parachute and its cords.

NASA's Mars Phoenix Lander can be seen parachuting down to Mars, in this image captured by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. This is the first time that a spacecraft has imaged the final descent of another spacecraft onto a planetary body.

From a distance of about 310 kilometers (193 miles) above the surface of the Red Planet, Mars Reconnaissance Orbiter pointed its HiRISE obliquely toward Phoenix shortly after it opened its parachute while descending through the Martian atmosphere. The image reveals an apparent 10-meter-wide (30-foot-wide) parachute fully inflated. The bright pixels below the parachute show a dangling Phoenix. The image faintly detects the chords attaching the backshell and parachute. The surroundings look dark, but corresponds to the fully illuminated Martian surface, which is much darker than the parachute and backshell.

Phoenix released its parachute at an altitude of about 12.6 kilometers (7.8 miles) and a velocity of 1.7 times the speed of sound.

The HiRISE, acquired this image on May 25, 2008, at 4:36 p.m. Pacific Time (7:36 p.m. Eastern Time). It is a highly oblique view of the Martian surface, 26 degrees above the horizon, or 64 degrees from the normal straight-down imaging of Mars Reconnaissance Orbiter. The image has a scale of 0.76 meters per pixel.

This image has been brightened to show the patterned surface of Mars in the background.

Monday, May 26, 2008

Mars Phoenix Lander Lands on Mars

Photos credit: NASA/JPL-Calech/University of Arizona

I'm happy to say that the Mars Phoenix Lander has landed safely on Mars. The spacecraft was launched from Cape Canaveral last August, and successfully set down in the part of Mars known as the Vastitas Borealis (literally, northern vastness or widespread lowlands). The Vastitas Borealis lies 3-4 km below the mean radius of the planet (the Martian equivalent of sea level), that completely encircles the northern hemisphere of Mars from about 50°-60° North to about 80° North, where it meets the Planum Boreum, the northern polar plain where the ice cap is located. It is believed that the Vastitas Borealis may have been an ocean in Mars' ancient past, and that the Phoenix Lander may discover ice beneath a thin layer of dirt.

Unlike the rovers
Spirit and Opportunity, which are both mobile and have been operational for a number of years, the Phoenix Lander will remain in one place, where it landed, and is expected to survive for about three months or so, when the weather will freeze the spacecraft. In the meantime, the Phoenix Lander has an arm that will scoop soil and ice samples and place them into several chemistry laboratories inside the spacecraft, which will try to determine the soil chemistry, the amount of water and water vapor in the soil, and the soil's level of conductivity. The goal is to determine whether the Martian environment has ever been favorable to microbial life. In addition to the above-mentioned equipment, there's also several cameras on board plus a meteorological station, all of which are standard equipment for Martian vehicles today.

The two photos here are some of the first images taken by the
Phoenix Lander. Both photos, which are approximate-color images, show a landscape that is strewn with tiny pebbles and shows polygonal cracking, a pattern seen widely in Martian high latitudes and also observed in permafrost terrains on Earth. The polygonal cracking is believed to have resulted from seasonal freezing and thawing of surface ice.

Sunday, February 3, 2008

Butterfly Crater in Hesperia Planum, by Mars Express

Credits: ESA/DLR/FU Berlin (G. Neukum)

Because I truly am a glutton for punishment, I've started another blog, The Ministry of Space Exploration, which focuses on the remainder of the universe other than Mars. This particular post happens to be the first one written at The Ministry since that blog started. Please visit The Ministry of Space Exploration.

This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, shows a large elliptical impact crater in the Hesperia Planum region of Mars.

The HRSC obtained these images during orbit 368 with a ground resolution of approximately 16.7 meters per pixel. The scenes show the region of Hesperia Planum, at approximately 35.3° South and 118.7° East.

[The crater measures] ...approximately 24.4 km long, 11.2 km wide and reaching a maximum depth of approximately 650 meters below the surrounding plains.

Ejecta from this impact can be seen extending away from the crater, including two prominent lobes of material north-west and south-east of the crater.


This appears to be an impact crater that was subsequently resurfaced by lava flows, preserving the outline of the underlying crater. The curving features visible in the north of the image, known as 'wrinkle ridges,' are caused by compressional tectonics.

While the majority of impact craters are relatively circular, the elliptical shape of this impact crater suggests a very low impact angle (less than 10 degrees).

The long axis of the impact crater is viewed as the impacting direction of the projectile. Similar elliptical craters are observed elsewhere on Mars, as well as on our Moon.