Science! By Graham Templeton May. 14, 2014 7:28 am
In space, it’s generally unusual for things to line up. When they do — for instance when the orbits of planets fall along a rough plane — we usually require a robust explanation to overcome out basic incredulity. Sometimes, though, these things happen due to sheer luck, and that’s all we can say about the recent images capturing Mars’ largest moon Phobos crossing in front Jupiter. Visible in this shot as a small glowing dot near the center of the frame, the gas giant is completely obscured by the much closer Martian satellite. Captured in June of 2011, this event of course only occurred from the perspective of a single instrument — along all other sight lines, the two objects were no closer than at most other times.
The camera that*captured these images is on a missioned called the Mars Express, a relatively small project by the European Space Agency. Launched in 2004, it consisted of an orbiter and a lander — though the lander, the Beagle 2, did not survive touchdown. Had it landed successfully, the Beagle 2 would have allowed the ESA to start doing exobiology work on Mars a good eight years before NASA’s Curiosity would land to achieve the same goals.
These three photos show Phobos crossing the camera’s view of a distant Jupiter.
The orbiter is still in good condition, however, and by the time it took the pictures above the ESA had already extended its mission three times. The fifth and latest extension sees the Express orbiter continuing to function at least until the end of 2014 — but it could very easily get another extension after that. Despite the failure of its lander, the Mars Express mission was a big enough success that it spawned the orbiter-only mission Venus Express — which is still in operation today.
Our pictures of Phobos has increased steadily over the years.
Phobos is an interesting little satellite in its own right, mind you. It orbits extremely close to Mars, moving faster than required for geosynchronous movement — it zips across the Martian sky roughly twice per Martian day. For a long time, some scientists believed its odd orbital characteristics implied that the moon was in fact hollow, but now astronomers refer to Phobos as a “rubble pile.” This means that Phobos is not actually one enormous rock — a monolith — but rather a loose collection of separate rocks held together by gravity. This makes its density very low, since there are empty spaces between the rocks that make it up, and this density is what allows its odd orbital behavior.
Phobos is one of the most heavily studied natural satellites, as of right now. Aside from our own Moon, it’s the one we know the most about. Unfortunately, it doesn’t seem to hold as many interesting tidbits of information as, say, Enceladus or Titan, which have amazing features like hydrocarbon seas and super-cryo-volcanoes. Still, as evidenced by these snapshots, Phobos will remain an object of study for some time — even when we’re not trying.
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The camera that*captured these images is on a missioned called the Mars Express, a relatively small project by the European Space Agency. Launched in 2004, it consisted of an orbiter and a lander — though the lander, the Beagle 2, did not survive touchdown. Had it landed successfully, the Beagle 2 would have allowed the ESA to start doing exobiology work on Mars a good eight years before NASA’s Curiosity would land to achieve the same goals.
These three photos show Phobos crossing the camera’s view of a distant Jupiter.The orbiter is still in good condition, however, and by the time it took the pictures above the ESA had already extended its mission three times. The fifth and latest extension sees the Express orbiter continuing to function at least until the end of 2014 — but it could very easily get another extension after that. Despite the failure of its lander, the Mars Express mission was a big enough success that it spawned the orbiter-only mission Venus Express — which is still in operation today.
Our pictures of Phobos has increased steadily over the years.Phobos is an interesting little satellite in its own right, mind you. It orbits extremely close to Mars, moving faster than required for geosynchronous movement — it zips across the Martian sky roughly twice per Martian day. For a long time, some scientists believed its odd orbital characteristics implied that the moon was in fact hollow, but now astronomers refer to Phobos as a “rubble pile.” This means that Phobos is not actually one enormous rock — a monolith — but rather a loose collection of separate rocks held together by gravity. This makes its density very low, since there are empty spaces between the rocks that make it up, and this density is what allows its odd orbital behavior.
Phobos is one of the most heavily studied natural satellites, as of right now. Aside from our own Moon, it’s the one we know the most about. Unfortunately, it doesn’t seem to hold as many interesting tidbits of information as, say, Enceladus or Titan, which have amazing features like hydrocarbon seas and super-cryo-volcanoes. Still, as evidenced by these snapshots, Phobos will remain an object of study for some time — even when we’re not trying.
More...
