Changing Planet

Solar Conjunction: Mars Missions Take a Load Off

The holiday season has officially descended upon us, and many a child is eagerly waiting for that jolly red roundness with a snowy white cap to appear in the sky.

Meanwhile, anyone whose day job requires listening for and deciphering radio signals from Mars is probably only too glad that white-capped red ball has hidden itself behind the sun, and will stay that way through the end of 2008.



—Image courtesy ESA

Last Friday Mars slipped into place behind the sun directly opposite to Earth observers, and over the next few weeks the red planet will drift through a line of sight very close to our stormy star.

This means that solar noise effectively blocks radio communications with the five craft now orbiting or actively exploring the face of Mars—and that means Mars mission engineers can take a bit of a breather.

Called solar conjunction, the radio blackout between Earth and Mars happens every two years, with the last one cropping up between October 18 and 29, 2006.

During the blockage, some missions decide to throw in the towel and go on hiatus.

Over at ESA, Mars Express controllers announced today they have temporarily shut off the craft’s Webcam and have prepped the probe for roughly a month of hibernation.

NASA’s Mars Reconnaissance Orbiter is also on winter break for the next couple weeks.

But while you’re waiting, mission scientists invite you to page through their catalog of 362 new 3-D images of Mars taken by the craft’s HiRISE camera.

[It’s like abstract art, but it’s science! And in X-mas colors… woot!]


—Image courtesy NASA/JPL/University of Arizona

Other Mars missions will keep doing a limited amount of science, although nothing that requires a steady stream of commands.

The NASA rover Opportunity, for example, was positioned pre-conjunction to be near an exposed rock, so that the robotic arm can reach out and take lengthy measurements of its composition.


—Image courtesy NASA/JPL

Of course this communications freeze only has a bearing on new data from Mars, and you can be sure that some scientists will be toiling away over information collected so far and what it can tell us about Mars past and present.

Next week, in fact, keep your eyes peeled for all sorts of news from the American Geophysical Union fall 2008 meeting, where yours truly will be reporting from San Francisco!

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