April 1, 2014
Image Mission Elapsed Time (MET):
Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
This image is approximately 200 m (660 ft) across
Peculiarly, the MESSENGER team today released images that appear to show the remains of several now-inoperative NASA spacecraft on Mercury's surface. The spacecraft remnants are clustered along the inner wall of a 400-m-diameter impact crater on Borealis Planitia, a large area of volcanic plains. The crater lies within an enigmatic region of Mercury that the MESSENGER team has informally dubbed “The Borealis Triangle.”
Remarkably, one of the spacecraft has been tentatively identified as Mariner 10, which flew by Mercury three times in 1974–1975. Mariner 10 was presumed to be in a heliocentric orbit, although it may have been imaged by MESSENGER three years ago to the day
. Stranger still, the Mars Global Surveyor (MGS) probe also seems to have been delivered to this spacecraft graveyard. MGS ceased operations at Mars in 2007, and a landing on Mercury was not part of its original mission design. Most unexpected of all is one of the twin Gravity Recovery and Interior Laboratory (GRAIL) spacecraft. The GRAIL mission ended in December 2012 when both craft were thought to have impacted the surface of the Moon, yet at least one of the spacecraft seems to have survived that impact and later repeated the feat on Mercury.
Although this remarkable finding was enabled by the increased resolution at which MESSENGER can now image the surface of Mercury as its periapsis altitude lessens with each orbit, the MESSENGER team is at a loss to explain this collection of inoperative spacecraft within the Borealis Triangle. MESSENGER Project Scientist Nat MacRulf
believes preternatural forces are responsible. “Both Mariner 10 and Mars Global Surveyor flew magnetometer experiments. What if something went wrong? Could we then be looking at the effects of a magnetically induced wormhole, like that generated during the Philadelphia Experiment in the 1940s? I don't see why not.” As to why the GRAIL spacecraft, which lacked a magnetometer, would also become caught in a magnetic wormhole, MacRulf simply scratched his head. “The darn thing's made of metal, isn't it?”
Not everyone agrees with MacRulf's assessment, however. MESSENGER Project Manager Ellen Summers favors a more prosaic explanation for how missions to other planets have ended up at Mercury. “Spacecraft are notoriously hard to direct, especially once they're switched off. It took one flyby of Earth and two of Venus before we eventually managed to steer MESSENGER toward Mercury. A spacecraft at Mars might easily make its way to Mercury if left to its own devices.”
Keen, nonetheless, to take advantage of this strange new observation, the MESSENGER mission operations and navigation teams met this morning to discuss plans to transition the spacecraft from an orbiter to a lander. “The crater in which we've spotted these decommissioned spacecraft, which we're proposing be named after Eloy d'Amerval
, would make a great site to make in situ
measurements of Mercury's strange Borealis region,” says MESSENGER mission design lead Adam McJames. He added: “If other craft can crash-land there, I don't see why we can't!” before rushing off to assist in using MESSENGER's own magnetometer to take readings of an unusual aurora-like phenomenon beginning to form above the Borealis Triangle. At press time, McJames, Summers, and MacRulf would not confirm reports of the appearance at Mercury of the Galileo spacecraft, last tracked plummeting deep into Jupiter's magnetically charged atmosphere in 2003.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
For information regarding the use of MESSENGER images, see the image use policy.