But with future telescopes, scientists say it may be possible to see past the blinding glare of the parent star to pick out just the faintlight passing through a small world's atmosphere or even reflected off its surface.
Now that Dr van Paradijs's team, and another led by Kailash Sahu at the Space Telescope Science Institute in Baltimore, have had time to look properly at the fading point of light, they have noticed afaint fuzz around it that looks as if it could be a galaxy playing host to a dramatic explosion.
To observe such a distant, faint object, scientists had to collect light through the telescopes over 37 hours, letting more and more light accumulate to see as deep as possible.