Posted by Emily Lakdawalla on 2012/03/22 10:28 CDT
Water ice at Mercury's poles? That's crazy, right? Mercury is so close to the Sun that it seems inconceivable that you could have water ice there. But Mercury's rotational axis has virtually no tilt (MESSENGER has measured its tilt to be less than 1 degree), so there are areas at Mercury's poles, most often (but not always) within polar craters, where the Sun never rises above the horizon to heat the surface.
Posted by Emily Lakdawalla on 2012/02/07 05:46 CST
There's been a bit of buzz on the Web this week regarding an ESA press release titled "ESA's Mars Express radar gives strong evidence for former Mars ocean." I don't ordinarily write about press-released science papers, but am making an exception for this one
Posted by Pat Donohue on 2012/02/03 10:02 CST
Guest Post: Patrick Donohue: Six days in the crater (day one)
Posted by Emily Lakdawalla on 2011/10/07 07:09 CDT
Today was (is) the last day of the Division of Planetary Sciences / European Planetary Science Congress meeting in Nantes, France.
Posted by Emily Lakdawalla on 2011/10/05 11:04 CDT
Today I largely spent in the MESSENGER sessions. They have a lot of data to talk about.
Posted by Emily Lakdawalla on 2011/10/03 11:55 CDT
Today they turned on the scientific fire hose at the Division of Planetary Sciences / European Planetary Science Congress meeting happening here in Nantes, France. My brain already feels full and I still have four more days!
Posted by Emily Lakdawalla on 2011/09/23 01:09 CDT
About four years ago I wrote a blog entry about an ESA press release about paper published in Nature that suggested that Saturn's moons Tethys and Dione might have volcanic activity, like Enceladus. A new paper published in Icarus casts doubt on that conclusion.
Posted by Emily Lakdawalla on 2011/09/20 01:58 CDT
When Hayabusa's sample return capsule was first opened and found to be very clean-looking inside, I doubted that there could be enough material for laboratory analysis. JAXA announced later that they scraped about 1500 dust grains from the inside with a teflon spatula, and these likely came from Itokawa.
Posted by Emily Lakdawalla on 2011/09/13 01:27 CDT
Jeff Moore's presentation was cool because of the discussion it stimulated. He considered what exogenic processes might be operating on Pluto's surface. What's an exogenic process? It's something that modifies the shape of the surface from the outside, and doesn't require the body to be geologically active inside.
Posted by Emily Lakdawalla on 2011/09/09 01:05 CDT
The second day of the New Horizons Workshop on Icy Surface Processes was about geology and geophysics. This long post just covers the first talk of that day.
Posted by Emily Lakdawalla on 2011/08/30 11:27 CDT
Today and tomorrow I'm attending the New Horizons Workshop on Icy Surface Processes. The first day was all about the composition of the surface and atmosphere of Pluto, Charon, Triton, and other distant places.
Posted by Emily Lakdawalla on 2011/08/17 07:33 CDT
Much has been made of the "enigmatic mound" within Gale crater, which will be the target of the Curiosity Mars rover's investigations. The 5,000-meter-thick section rocks in Gale's central mound will be fascinating to study, but the fact that Gale has a central mound that's taller than its rim is not at all unusual on Mars.
Posted by Jason Perry on 2011/05/13 11:44 CDT
A fresh report was published online yesterday in Science Express on the discovery of a magma ocean beneath the surface of Io. Big news! This is a paper I've been looking forward to seeing for more than year and half.
Posted by Emily Lakdawalla on 2011/04/19 11:21 CDT
When Mariner 10 flew past Mercury, it caught an immense impact basin lying half in and half out of sunlight, which they named Caloris. Even with only half the basin visible, scientists knew it was one of the largest in the solar system. Geologists had to wait more than 25 years to see the rest of Caloris, and when they did it turned out to be even bigger than they had thought. But the fact that Caloris was only half in sunlight was fortuitous in one sense, because it meant that the spot on Mercury that was exactly opposite the area of the Caloris impact was also partially in sunlight. That spot looks weird.
Posted by Emily Lakdawalla on 2011/02/07 02:09 CST
Here's a neat paper just published in Geophysical Research Letters: "Mega-ejecta on asteroid Vesta." In it, Martin Jutzi and Erik Asphaug consider Vesta's shape -- which appears to be dominated by a very large impact crater centered at its south pole -- and ask how much of the great big asteroid Vesta's global appearance is likely to be dominated by the effects of that one large impact.
Posted by Emily Martin on 2010/08/16 01:42 CDT
In response to Emily's entry about finally getting her hands on a subscription to the planetary science journal Icarus, I thought I would report on an article from the most recent issue: Geology of the Selk crater region on Titan from Cassini VIMS observations, by Jason Soderblom and 11 other scientists.
Posted by Emily Lakdawalla on 2010/05/05 11:16 CDT
A recent entry by Bethany Ehlmann from the blog of the Planetary Geomorphology Working Group of the International Association of Geomorphologists demonstrates how you can combine the power of different types of data to tease out a rich story of the past history of one spot on Mars.
Posted by Jani Radebaugh on 2009/07/27 07:08 CDT
The Cassini spacecraft made its 59th flyby of Titan, Saturn's largest moon, on Friday, July 24, and in the last few hours we have received images from the RADAR instrument in SAR (Synthetic Aperture Radar) mode.