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Posts tagged NASA

Meanwhile, back on Mars …

JISHOU, HUNAN — Most of my posts lately have been about China, for obvious reasons, but it’s hard to abandon being a physics teacher. So, here’s a science post.

While humans have been flitting around in low-earth orbit, NASA-JPL’s Martian probes have been busy on the red planet. The arctic explorer, Phoenix, has discovered water ice in the soil and in the sky, detected snow falling from the clouds, and photographed the sun creeping up above the horizon as the martian winter approaches.

This sequence just fascinates me in particular. It shows clouds scooting through the sky, much as they would here in Earth. These are water-ice clouds, like the high-altitude cirrus clouds here.

Clouds in the martian arctic

Aside from practical issues like not having any oxygen to breath and sub-sub-zero temperatures, you could almost imagine yourself standing there watching the clouds go by.

Phoenix has been operating for more than four months, but the approaching martian winter solstice may kill the little fellow off. Temperatures are dropping to -120C (-184F), which is bad for its electronics and especially its solar panels. Carbon dioxide frost is forming on the solar panels, cutting down sunlight reaching the solar cells. And the sun itself, as it does in Earth’s arctic region, will soon dip below the horizon, not to return for three months.

So NASA-JPL scientists are trying to keep Phoenix busy every waking hour before it’s lights out for the probe. For details, visit the website.

Mercury’s “far side” for the first time, takes closeups

The MESSENGER probe captured this image of Mercury yesterday from 27,000 km away, giving us our first view of this previously unseen side of the planet. At the time, the probe was receding from its first flyby approach. [Click on the image to see a larger version.]

Mercury from 27000 km

As MESSENGER passed by, it snapped this image of the “near side” of Mercury, showing the crater Vivaldi on the right. Mariner 10 had imaged this part of Mercury on its pass in 1974.

Close up

NASA will be releasing more images as MESSENGER sends them for processing.

MESSENGER successfully flies by Mercury

The MESSENGER probe zipped past Mercury yesterday in the first of three flybys needed before it settles into a regular orbit. NASA scientists say the probe survived the encounter, which brought it to within 200 km (124 miles) of the planet’s surface.

MESSENGER is the first probe to visit Mercury in 30 years, so planetary scientists are excited to see what new data the new probe returns. MESSENGER (short for “MErcury Surface Space ENvironment GEochemistry and Ranging” — NASA must have a special office to devise names like this one) will investigate Mercury in ways that were not possible when Mariner 10 paid it two flyby visits in 1974. Mariner 10 was able to image only one side of Mercury.

Here’s an image of Mercury taken by MESSENGER on its approach Sunday, from 760,000 kilometers away (about twice the distance from the Earth to the Moon). (Click on the image to see a larger version.)

Mercury

After two more flybys this year and next, MESSENGER will settle into a regular orbit in 2011 when it will begin a longterm study of the innermost planet, the first in its history. The peculiar trajectory is a fuel-saving measure, to enable the probe to “catch up” to Mercury in its fast orbit around the Sun. [Earth travels at an average of 30 km/s; Mercury at 48 km/s. A more direct route would require burning a lot of fuel to speed the probe up and change its orbit.]

Buddy, can you spare a dime?

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