Link to the initial story and use the same images It's not every day someone finds 11 moons that had gone unnoticed in the four centuries since the telescope was invented and Galileo figured out that Jupiter had four satellites and the Earth couldn't be the center of the universe. Yet, remarkably, it has happened twice in the past two years -- in
January 2001 and again Thursday. SPACE.com had some questions for the University of Hawaii's David Jewitt, one of the researchers involved in bringing the Jovian moon count from 17 to 39 in a mere 16 months. In particular, we wondered how many moons might eventually be found around the great big planet.
SPACE.com: Why do you find (or announce) these things in big batches, rather than one at a time?
David Jewitt: We take the discovery data all at once. Then we spend months weeding out suspect or unreliable objects until we have a set we can trust. Then we announce them. So, they are all "pipelined" together.
SPACE.com: You must have pondered by now how many moons might ultimately be found around Jupiter. What are your guesses?
DJ: It depends on whether the size distribution is truncated at small sizes (as it should be according to one theory of the capture of these satellites), or continuous down to dust. In the former case we would have a finite number, in the latter it would be effectively uncountable.
SPACE.com: No guess then on how many Jovian satellites there might actually be, assuming a lower cutoff of 1 kilometer?
DJ: A hundred down to 1 kilometer, but that's just a guess.
SPACE.com: And what about Saturn? Can it still leapfrog into the satellite lead again with enough observations? [Saturn
held the lead two years ago.]DJ: Sure. But Saturn is twice as far away and objects of a given size appear 16 times fainter than at Jupiter. So, Jupiter is a better target if the aim is to clarify the whole population. A lot will be learned, though, by comparing the satellite systems of different planets.
SPACE.com: What insights are you starting to think about based on this now fairly large volume of small satellites around Jupiter?
DJ: The main question is, "How were these captured?" Both leading hypotheses -- not much more than hand-waving speculations, really, although there has been some quantitative work recently -- suggest that capture occurred very early in solar system's history. Maybe earlier than 1 million years, even before Earth had grown. So, we hope to understand something about this very early phase.
SPACE.com: Will your team continue to look for more moons around Jupiter as fervently as you have up to now?
DJ: We hope to. We have to compete for telescope time like everybody else, and there are lots of hungry extragalactic astronomers pummeling us for looking at objects that are "too close!"
The original story about the discovery
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