Turns out the black sphere was not a spaceship, but what scientists call a "prominence."
It is clearly visible in a series of images released by Solar Dynamics Observatory and processed by NASA.
"Telescope images captured of the sun on Monday (March 12)," reports LiveScience.com, "show what appears to be a planet-size shadowy object tethered to the sun by a dark filament." I think it looks more like a planet-sized sperm cell, but that's probably not what it is.
"In the image sequence," says LiveScience, "a burst of brightly lit material can be seen erupting from the sun's surface surrounding the dark object, after which the orb detaches from the sun and shoots out into space."
"Complex magnetic fields operating in the Sun's outer reaches," says an ITN report, can cause plasma clouds "to lift and swirl before falling back down again."
NASA scientists don't think this is either a spaceship or, as some others theorized, the birth of a new planet. The scientists are probably still chuckling over the fact that some folks think such crazy things.