THE COSMIC DIARY NETWORK

Wind at the Mars InSight landing site
Published 12/27/2018 in Lori Fenton's Blog Author lfenton
InSight landed in Elysium Planitia on 26 November, 2018, about a month ago as of this writing. Pictures show that it's a flat place, with small scattered rocks lying around. Unlike in Gale crater, where Curiosity is slowly working its way up the side of a 5 km mountain with a spectacular view of the crater rim, InSight's landing spot is a little boring. InSight's view in Elysium Planitia Curiosity's view in Gale crater Image Credit: NASA/JPL-Caltech Image Credit: NASA/JPL-Caltech/MSSS In a way, though, that's interesting, if simply for the contrast between the two sites. Despite this big difference in relief, there is one thing the sites have in common: the big global-scale wind patterns. In Gale crater that big wind pattern is a bit muted, and the local topography can create its own winds, which can in turn either work to augment or cancel out the big global wind patterns. But nothing changes the fact that Mars'... read more ❯

Welcome Insight lander, you are on Mars!
Published 11/26/2018 in Franck Marchis Blog Author Franck Marchis
Congratulations to  NASA, JPL, Lockheed Martin and international partners for landing  the Insight Lander on Mars a few hours ago. Like millions of people, I watched the NASA Live program from JPL which showed live the landing of the InSight vehicle on the surface of Mars. Beyond the typical sensationalism (the event was nicknamed "7 minutes of terror") of the program,, NASA spent a large amount of time explaining the engineering challenges  of the EDL: Entry, Descent, Landing with its thousands of steps; the science InSight will conduct so we can better understand the interior of the Red Planet, and finally the humans involved in the building and designing such a complex mission. NASA announced that the mission has successfully landed on Elysium Planitia, near the equator of Mars... read more ❯

The martian wind is a geologist
Published 10/18/2018 in Lori Fenton's Blog Author lfenton
Right now, the Fourth Landing Site Workshop for the Mars 2020 rover mission is happening. It's the last one, and in a few hours the scientists attending the workshop will vote on which of four sites they think the rover should land. I love the geology, but mostly I love one little corner of geology: where the rocks meet the atmosphere. I like how studying the rocks can teach us about how the atmosphere, and therefore the climate, has changed over time on Mars. There are signs of windblown things pretty much anywhere you look on Mars, and since none of the landing sites is within range of an actual dune field, I'm not really partial to any of the proposed sites. One of the proposed sites is in Gusev crater, taking us back to where the Mars Exploration Rover Spirit went. That would be great - they obtained a lot of... read more ❯

Pretty little dune field in Noachis Terra
Published 10/8/2018 in Lori Fenton's Blog Author lfenton
Noachis Terra is an ancient terrain on Mars, located in the mid southern highlands. It's the home of many dune fields, big and small. Here's a fairly small one. You can't see it, but this is the floor of an unnamed crater. If you follow the link to the CTX image, you'll see that there's a much larger dune field to the south, trapped in a pit eroded into the floor of the same crater. If you look carefully, you'll see that the dunes on the east side look a bit like barchans that are migrating southwestward, and on the west side the dunes look a bit like barchans that are migrating southeastward. This dune field is here because those two winds converge at... read more ❯

Lyot crater, Mars
Published 9/28/2018 in Lori Fenton's Blog Author lfenton
It's a rough day. A tsunami in Indonesia has killed many people, and the pain is so fresh that there's not even a death count yet. A couple of my good friends are going through various personal crises that will affect them for the rest of their lives. And if you're in the US, then one way or another you're probably upset about what's going on with the Supreme Court nomination. I should be working on any number of other things. There are projects to complete, and new projects that need to get sorted out before they begin. But for the moment I need to clear my head, and I'm going to do that by talking about Lyot crater. (BTW, I made most of these screenshots using JMARS, which anybody can download for free and use. All funded by US tax dollars, making NASA's hard-won Mars images available to the world. Take... read more ❯

Complexity
Published 9/24/2018 in Lori Fenton's Blog Author lfenton
Being a geomorphologist and reading a landscape is a little bit like being one of the forensic scientists on CSI (or choose your own favorite investigative show). A Mars geomorphologist usually has to do this entirely by remote sensing. So now imagine that forensic scientist trying to piece together a crime scene by peering at images taken by a drone. On Earth, at least, a geologist can head out to the actual field site and take samples and do some honest labwork to figure out how ancient landscapes formed. Planetary scientists aren't often so lucky (although we do use analog sites on Earth to try to learn something about other worlds). Take this scene for example. I've purposefully left it at full resolution (25 cm/pixel, click on it to see), but it's not the whole image. Be sure to follow the link to the HiRISE website if you want to see... read more ❯

The End of Kepler – It’s not over yet but it will happen soon.
Published 9/20/2018 in Franck Marchis Blog Author Franck Marchis
The Kepler space telescope, which was launched in March 2009, is the tenth NASA Discovery mission and the first dedicated to searching for and studying exoplanets. It was scheduled to operate for about four years, but is still active almost a decade later and after its scientific objectives changed when it was renamed the K2 mission. Despite these tremendous successes, scientists are now concerned about the health of the spacecraft, and a team of engineers and astronomers are working together in hopes of extending the spacecraft’s data-gathering capabilities for as long as possible. In May 2013, loss of a second reaction wheel should have ended the mission, but Kepler was rebooted, renamed the K2 mission, and given a new goal: use the telescope’s high-photometric precision to observe stars and solar system objects located along the ecliptic. Each cycle of observation, which is known technically as a campaign, lasts about eighty days... read more ❯

Ever shifting
Published 9/13/2018 in Lori Fenton's Blog Author lfenton
Dunes are just so amazingly beautiful. I'll never get over how nature can sculpt such regular patterns into endlessly overlapping structures. Here's a small bit of a dune field trapped up high between mountains in the middle of Coprates Chasma. Here I'm not focusing on their setting, but rather the intricate structures of the dunes themselves. The dunes are formed by wind funneling down a narrow valley, headed towards the floor of the much bigger chasma (to the left, far offstage). Here we are in the midst of a dune field, looking at a rippled sandy surface that piles into dunes. The dunes avalanche downwind, slowly advancing forward (mainly toward the left here), as successive avalanches carry more sand down the slip faces. Ripples cover every surface they can - the wind seems to like to make them. They'll even form on slip faces, only to be erased later by avalanches... read more ❯

The end of winter
Published 8/28/2018 in Lori Fenton's Blog Author lfenton
Richardson crater is located at 72ºS, about 1000 km (~621 miles) from the south pole of Mars. It's a moderately large crater, about 90 km (56) miles across, and it's mostly filled by one of the biggest dune fields in the southern hemisphere. The dune field has been targeted repeatedly by HiRISE, with a recent count of 83 images. I've probably included images in my blog in the past, but a quick search shows I didn't label them (and I'm far too lazy to go searching). But no matter, since there are plenty of brand new images of the place to keep us happy. Like this one:   If you're confused by which way is up: the sun is shining from the left toward the right. The curvy bright... read more ❯

Different sands
Published 8/21/2018 in Lori Fenton's Blog Author lfenton
There's a lot we don't understand about the sediment on Mars. Water, wind, ice, changing temperatures, and volcanic eruptions can all break rocks into grains small enough for the wind to transport. The smallest grains are lofted by the wind, contributing to dust storms, and settling out as fine layers of dust. Slightly larger grains hop (saltate) along the ground and self-organize into beautiful ripples and dunes. Even larger grains (more than a few millimeters in diameter) might be moved by the wind on occasion - these grains are too big to saltate (unless the wind is really strong), but repeated impacts from smaller saltating grains can slowly make them move (Aeolian scientists call this sort of movement creep. Yep.). Those bigger grains can also self-organize, along with the smaller grains, into a different type of ripple. That could be what's happening in the image below. Two... read more ❯

Capturing a Snapshot of Pluto’s Atmosphere. The Story of an Occultation
Published 8/19/2018 in Franck Marchis Blog Author Franck Marchis
Last Tuesday night, a large number of amateur and professional astronomers located across Mexico, the US, and Canada took advantage of a rare and exciting opportunity: observe a blinking star while Pluto occulted it. In Southern California, the SETI Institute, the Observatoire de Paris, Unistellar, and Oceanside Photo and Telescope (OPT), one of the largest telescope retailers in the world, collaborated to observe this rare event and gather the precious data we need to understand Pluto’s atmosphere and climate. Here is our story.   Like most events in the world of modern astronomy, this one started with an email. In February 2018, I sent my colleagues at the Observatoire de Paris a message letting them know that the eVscope was ready and able to observe occultations. We had by then already observed our first occultation, by main-belt asteroid 175 Andromache, from the south of France and I wanted to get input from Bruno... read more ❯

Where dunes once trod
Published 8/13/2018 in Lori Fenton's Blog Author lfenton
Mars has been dusty, and that's affecting the quality of HiRISE images (just look at the recent images in the catalog and you'll see they're not that great). That's made it hard for me to choose a good one for my blog. I suppose I could go with a grainy image and talk about things like the "cost of real data" and "one person's noise is another person's data" (because surely someone will make use of those poor-quality images to track dust clouds, or something). I'm waiting to see where the bright dust falls out on the surface, because I want to show you dust-covered dunes, and then watch how the wind slowly clears them off. It will be a bit like watching snow melt in the spring, if you live in a place that gets snow in the winter. But first I found a really neat image of missing dunes. No... read more ❯

Oh, Mars!
Published 8/2/2018 in Lori Fenton's Blog Author lfenton
The HiRISE camera has a website called HiWish that lets anybody (yes, even you!) make image requests. That's right, you can choose any spot on Mars that HiRISE can see, pick any season (or let them pick for you if you don't care), and one day the Mars Reconnaissance Orbiter's path will fly over your spot and, if it isn't scheduled for other observations, HiRISE will take your image! I've made several requests that way. Sometimes I want to get repeat coverage of an area to see if dunes and ripples have migrated - that requires both a "before" and an "after" image. Sometimes I want a closer look at something that isn't easy to figure out using other images - HiRISE is still the highest resolution camera sent to orbit Mars, so it's sort of like whipping out a magnifying glass to have a closer look at something you could... read more ❯

Spring is a messy time
Published 7/16/2018 in Lori Fenton's Blog Author lfenton
In many areas on Earth that get winter snow, spring thaw is a messy time. Frozen ground turns to mud, and there may be runoff everywhere from melting snow and spring rain. Or if you live in a place that gets winter rains, spring might be the time when mudslides are most common. Spring can be messy on Mars too, although in this case the ice isn't H2O, but CO2. Also, it's not melting, but rather sublimating. But that can still make a big mess. Here's part of a dune field in early spring, located in the high southern latitudes. Normally dunes on Mars are dark because they're made of dark sand, but here they're still mostly covered by bright wintertime frost. If you didn't already know there were dunes here, you might never guess that's what's there. Zoom in (click on the image) and you'll see the ice is draped... read more ❯

Field of barchans
Published 7/8/2018 in Lori Fenton's Blog Author lfenton
It's July, and I've had a busy summer so far. This is my first post in a few weeks - I've been out at various meetings, and last week I spent with my family on vacation. The one week of normal work I had was spent furiously working to help a colleague put together a paper. That left me no time to share pretty pictures with the world. So finally I'm back and able to make another blog post. I decided to make it simple: just a field of pretty barchans. Barchans are one of the simplest types of dunes - they're just piles of sand blown by wind coming from only one direction. The barchans here in Lyot crater are some of the smallest dunes (the smallest one here is ~60 m, or ~200 ft across, which... read more ❯