How come Hubble's pictures of galaxies billions of light years away are so beautifully detailed, yet the pictures of Pluto, which is so much closer, are just little blobs? I get asked this question, or variations of it, a lot. Here's an explainer.
Pluto is now known to have at least five moons (Charon, Nix, Hydra, P4, and the newly discovered P5), and its burgeoning population might pose a risk to New Horizons during its flyby, three years from now.
A newly published paper shows trans-Neptunian object Salacia to be unexpectedly large; it's somewhere around the tenth largest known thing beyond Neptune. It has a companion one-third its size, making it appear similar to Orcus and Vanth.
My notes on a two-part presentation by collaborators Jim Richardson and David Minton about the sizes of things in the Kuiper belt, a story they told by looking at Saturn's moons. How does that work? What connects Saturn's moons to the Kuiper belt is craters.
I'm preparing a talk for the Pacific Astronomy and Telescope Show here in Pasadena on Sunday afternoon at 1:45. I have spent the morning putting together a slide that I have long wanted to have for presentations.
NASA funds regular meetings of scientists who work on different parts of the solar system to provide scientific input into NASA's future plans. These "analysis groups" are known by their acronyms, all of which sound kind of horrible, but none has quite as terrible-sounding an acronym as "SBAG," usually pronouced "ess-bag," the Small Bodies Assessment Group.
Here are some of the noteworthy items from the morning's session on "Small Bodies: A Traverse from NEOs to TNOs" and the afternoon's session on "Asteroid Geophysics and Processes: Surfaces and Interiors."
As part of a big, ongoing project to make a comparison chart of the dimensions and physical properties of solar system objects I've spent the morning tackling the difficult problem of summarizing the physical characteristics of the biggest things that are out there beyond Neptune.
Several astronomers pointed their telescope at Eris to watch it pass in front of a background star. Occultations permit precise measurement of the diameters of distant, faint objects, and it turned out that Eris was much smaller than previously thought, so much so that its diameter may turn out to be the same as, or even smaller than, Pluto's.
An awful lot of the talks in the Pluto session on Tuesday morning, October 5, at the Division of Planetary Sciences meeting spent more time focusing on how bad weather conditions were during the astronomers' attempts to view Pluto as it occulted background stars than they did on any measurements or science that came out from the data.