THE COSMIC DIARY NETWORK
Once covered, now revealed
March 29, 2021 Mars is such a fun place. We're finding out that it's got oodles of geologic history. It's got layers deposited by wind and water and lava, altered in place (sometimes many times), then eroded again by wind and water and lava. It's never boring. My favorite, of course, is the wind. I really like modern dunes that are now crawling across the surface and the wind blows their sand along. But I also like old ones that preserve information about the wind patterns from a long time ago. This is ESP_068039_1780, a really spectacular HiRISE image that shows a lot of wind erosion has happened (as always, click to see a bigger version): This is in the Medusa Fossae Formation, perhaps the most deeply wind-scoured region on the planet. Recent work suggests that it may be the largest source... read more ❯
Both wind-carved *and* ancient
1 February, 2021 Are we tired of the pandemic yet? My kids haven't gone to an actual school since last March. Fortunately we're all healthy. I'm able to do most of my work, but it's not easy. So let's go look at Mars. (I do that when I feel stressed and it usually makes me feel better.) Here's a neat HiRISE image that was recently released (click on any of these images for a closer view): It looks kinda crazy, doesn't it? It's a mostly smooth surface with some subtle linear grooves (or bumps, if you're a glass-half-full person, which I am not). But it's got a decent number of craters on it, so we're probably not looking at a polar... read more ❯
Did Proxima Centauri just call to say hello? Not really!
Greetings, Citizens of Earth! You’ve probably heard about the story, published in The Guardian, a respectable newspaper in the UK, about the potential discovery of an alien signal from the Proxima Centauri system, the star closest to us. This article, and a companion piece in Scientific American, noted that in April and May 2019, the Parkes telescope in Australia was listening to Proxima b, a red dwarf. This star is known to be active, and this listening was part of a stellar-flare survey. Shane Smith, a student at Breakthrough Listen, a program privately funded by Yuri Milner to search and find so-called technosignatures, or signals that indicate the existence of a civilization like ours, checked out the data. He found an exceedingly curious narrowband emission, needle-sharp at 982.002 megahertz. The team inspected the data, confirmed its veracity, and named it BLC1, for “Breakthrough Listen Candidate 1.” The name clearly identifies what it is. It’s a... read more ❯
The zebra dunes of the martian subarctic
16 December, 2020 This year I haven't had time to write many blog posts. That's a shame, because they're what often reminds me of how amazing Mars is (and by extension, the Earth, and all the other worlds out there). The pandemic has left its mark on all of us. I'm fortunate enough to be funded (but that may end - I don't foresee spending on NASA to be plentiful in the coming hard years). The upside is that for now I can work. The downside is that I'm behind in all of my projects, and also trying to get my kids to do their schoolwork (such as it is this year). So let's look at something cool on Mars. Let's go see the zebra dunes. These zebra dunes: Dunes aren't typically covered in stripes like that. Not... read more ❯
How I Plan to Help Save Science Education with the Unistellar eVscope!
Lightning strikes a dream Several weeks ago I had a dream during the intense lightning storms in and around San Francisco and the greater Bay Area, which then sparked some of the devastating wildfires that we are still recovering from and experiencing. In this dream, I was in my high school chemistry class. My group was asked to answer the problem on the board and when we went up and didn’t know the answer, everyone, including the teacher (and Nelson from the Simpsons), laughed at us. This inspired me to share the failure of the American education system with my students and how the current system values answers over process and problem solving while squashing their creativity and curiosity. Process, problem solving, knowing how to think rather than what, and curiosity and creativity are intrinsic and vital skills for science, education, and innovation in our modern time. Video: Neil deGrasse Tyson on how... read more ❯
Dune on a hill
Sept. 2, 2020 Dunes don't usually form on hills. They're made of sand, which is moved by wind (and water and ice) and tends to linger where it gets stuck. You probably know this intimately if you've spent time at a sandy beach. It's true not only on the scale of the threads of a beach towel and in jeans pockets, but also on a larger scale. Dune fields are made of windblown sand that piles up in valleys, or whatever topographic low it's being blown past. The biggest sand sea on Mars, for example, is found at the bottom of the biggest basin on the planet (most well-known is Olympia Undae). The second-largest accumulation of dunes on Mars (outside the huge north polar sand seas) on Mars are found on the floor of the enormous and deep Valles Marineris (examples like these). So when I was looking for new backgrounds for... read more ❯
Those crazy southern polar dunes
July 17, 2020 A couple months ago I wrote a blog post about defrosting dunes in Jeans crater, some wild southern polar dunes on Mars. Well it's been that time of year on Mars, so I'm going to show some more. These aren't in Jeans crater, but in another unnamed crater at about 70°S (that's pretty far south). First let's have a look at the crater, for some context: CTX images of the crater (Image credit: NASA/JPL/MSSS, made in JMARS) MOLA elevation + shaded relief of the crater (Image credit: NASA, made in JMARS) On the left above are images of the crater and the funky-looking dune field inside it. On the right is elevation, which might help you see where the craters are. Our crater is about 43 km (26.7 mi) across, and its floor sits at an elevation of about 500 m (0.31 mi) above the Mars datum (what would be sea... read more ❯
Planetary Defense with the eVscope Network - First results
In March 2020, Joé Asencio joined the SETI Institute to develop the potential of the Unistellar network for Planetary Defense. Part of his work is to build the tools necessary to analyze astrometry and photometry of Near-Earth Objects (NEOs) and connect with our network of citizen astronomers. This is a summary of the first results obtained with the eVscope. Let's first thank our backyard astronomers who contributed to this program: Sam Rihani, Kevin Cross, Jacques Bérard, Nicole Ruel, Masaaki Yamato, Gilles Cartry and the Unistellar team. Because of their contribution we have validated the use of the eVscope to contribute to this field of research. Here a summary... In less than a month of observation, we have already submitted more than 20 observations to the Minor Planet Center, or MPC, (asteroids 52768, 1984QY1, 913, 652, 3, 12…) confirming the potential of the eVscope... read more ❯
The new crater
June 15, 2020 Utopia Planitia is an ancient plain in the northern lowlands of Mars, thought to be made of volcanic rocks that were buried, more than 3 billion years ago, by sediments carried by water coming down from the southern highlands (this is the wonderfully vast late Hesperian lowland unit ("lHl") of Tanaka et al., 2014). After the sediments piled up, most of the surface hasn't had a lot happen to it, although in some places there are signs of glacial activity and other modifications by ice. Here, though, what is interesting to me is the scattered windblown bedforms, like those in the scene below (yeah, I'm using the more generic and technical term bedform, because the Mars aeolian community hasn't yet agreed on whether they are dunes, ripples, or something different that's nearly unique to Mars, but rather they're the more ambiguous transverse aeolian ridge, or TAR. Either way, you... read more ❯
Hills with tails
June 8, 2020 No long descriptions or explanations today, just a pretty picture of a lee dune (the dark rippled finger extending down the left side of this image): The rounded gray hills at the top are part of the little central peak of a~25 km diameter crater. Why is the dune there? Well first let's see where it is to begin with. Here's some context: Dark sand is being blown through this area. Some has gotten caught inside this crater, the way crumbs get stuck in between floor... read more ❯
Defrosting dunes in Jeans crater
May 26, 2020 There are sand dunes near both the north and south poles of Mars. The ones I'm showing today are on the floor of Jeans crater, which is down at 69.5°S (for reference, on Earth, some bits of Antarctica reach to this latitude). Jeans crater is 74 km (46 mi) across, and like many of the larger craters in the southern highlands of Mars, it's got a dune field in it. This far south, the dune field spends a lot of its time covered in seasonal CO2 frost. It's just past Mars' antarctic circle, which means it spends part of its winter in total darkness, and part of it summer in perpetual sunlight. Here's a little snippet of the dune field as of 5 April 2020: If you're not used... read more ❯
An occultation by the Potentially Hazardous Asteroid 1998 RO2 - Occultation par l'astéroïde géocroiseur 1998RO2
1998RO2 is a body classified as a potentially hazardous asteroid that has been and will be mentioned in the news in the next 2 weeks. With a diameter estimated to 2-4 km, it's one of the largest asteroid with this classification. First of all, let's clarify that we can say with confidence that it will NOT hit Earth since its orbit is well characterized with occultations collected since its discovery in 1998. We know that it will make a close flyby to Earth by the end of April 2020 and will be visible with binocular and naked eye from very dark site. We also know that on April 14 at around 2:14 CET, the asteroid will occult a 7-mag star in the constellation of Cancer for less than 1s. We are asking our Unistellar citizen astronomers to observe this event so we could characterize the asteroid, derive its size, shape... read more ❯
New Unistellar eVscope exoplanet light curve and exoplanet targets this weekend!
Dear Unistellar eVscope users, With your Unistellar eVscope you have the technology to detect planets orbiting other stars. Think about this--over 30 years ago planets around other stars (exoplanets) were hypothesized, but none yet were detected. Since the most agreed upon "first detection" of an exoplanet in 1992 around a pulsar, astronomers have detected thousands of exoplanets, but this has been done mostly through the use of expensive remote telescopes and highly technical techniques. Now, you and your eVscope can observe exoplanets with a few clicks on your smartphone and some time. I've been posting exoplanet targets for you and me to try and observe for the past few months. This is a pilot citizen science program for exoplanet detections that I am working on for my PhD. The eVscope had already proven successful in observing an exoplanet before I started my PhD work this year, however, we have been trying to... read more ❯
Comet Atlas: A comet for all of us?
Finally! After several years of waiting we may soon have, in Comet ATLAS, a bright, naked-eyed comet passing by Earth. The last visitor to do this was Comet 46P/Wirtanen, which was barely visible in December 2018 from highly polluted areas. Current models predict that Comet ATLAS could be brighter and easy to spot in the sky even for novice citizen astronomers. Of course, anyone who has a telescope can already witness brightness and morphological changes in the comet at it approaches the Sun. If, like a lot of us, you’re sheltering at home, this is the ideal time to look up with your binoculars or telescope and enjoy your date with a comet. Known officially as Comet C/2019 Y4 ATLAS, ATLAS was discovered on Dec. 28 2019 by the robotic survey Asteroid Terrestrial-impact Last Alert System, which is dedicated to the detection of near-Earth objects. At the time of its discovery,... read more ❯
Observe an Occultation by Asteroid Alikoski from San Francisco Bay Area Saturday evening
To all citizen astronomers, Are you at home like most of us? Good news, you can contribute to astronomy from your backyard on Saturday just after sunset. If you have an eVscope that's super easy. The asteroid (1567) Alikoski will occult a V-11.4 star during up to 2.4 second on Saturday March 29 at 8h18pm (in San Francisco, CA), so just at the beginning of the night . Because of its brightness and the duration of the event, this event is a great opportunity for all of us to learn about Alikoski, a rare-type carbonaceous asteroid from the outer region of the main-belt. So if you live between the two red lines and which include the San Francisco Bay Area, you might be able to see this event. WHAT IS AN OCCULTATION BY AN ASTEROID ? An occultation is an astronomical event defined by the passage of an asteroid in front of a star. Then,... read more ❯
Look up and let the stars lift your spirits AND exoplanet targets for Unistellar eVscope users!
Dear Cosmic Diary guests and Unistellar eVscope users, My heart and best wishes go out to you and to your families during the COVID-19 global crisis. I have been very busy adjusting to this new way of life in quarantine and social distancing to do my part in "flattening the curve" and staying safe, as I'm sure many of you also have. In addition to being a PhD student, I also teach high school physics full-time and my school in the Bay Area, CA, closed down for the pandemic on Friday, March 13. My teacher colleagues and I began teaching completely online beginning the following Tuesday (March 17). This has been a huge adjustment and learning curve for both me and my students, but I am proud of my school and fellow teachers for working so hard at my school and across the world to continue teaching via virtual online instruction and... read more ❯
The landscape in Arabia Terra
March 25, 2020 It's been an interesting few weeks. Like many folks, I'm trying to work from home while keeping my kids busy. I'm fortunate to have a job that allows me to work at home, so I can continue to make progress away from the office. It does mean that my work at the Mars Wind Tunnel at NASA Ames is on hold, as is my planned dust devil fieldwork. That's a bummer. But I've got plenty to work on in the meantime. I thought today I'd show off one of the many craters in Arabia Terra on Mars that has a lovely dune field. Arabia Terra is a vast region in the northern tropics that's full of craters and windswept sedimentary rocks. The Mars Exploration Rover (MER) named Opportunity landed in a part of Arabia Terra called Meridiani Planum. Today I'm going to show you a different part of the... read more ❯
MISSION UNISTELLAR : OCCULTATION PAR L'ASTÉROÏDE SIBERIA - UNISTELLAR MISSION : AN OCCULTATION BY SIBERIA ASTEROID
--- Version française --- The english version is available below. À tous les citizen astronomes d'Unistellar, Si vous possédez un eVscope et que vous souhaitez participer à une campagne de science participative, vous pouvez suivre les instructions ci-dessous. Cette campagne est très simple. Grâce à l'application Unistellar, votre mission se résumera à l'observation d'une étoile lorsqu'elle est occultée par un astéroïde. L'occultation que nous vous proposons d'observer concerne les personnes qui résident dans la zone entre les deux lignes rouges (voir ci-dessous). L'astéroïde (1094) Siberia occultera une étoile de magnitude 11,3 pendant 1,8 seconde ce samedi 28 Mars 2020 aux alentours de 00h58 (heure locale au Québec, CA). Si vous vivez à Montréal, vous êtes chanceux. C'est une grande opportunité pour vous comme pour les scientifiques. QU'EST-CE QU'UNE OCCULTATION PAR UN ASTÉROÏDE ? Une occultation est un évènement astronomique défini par le passage d'un astéroïde devant une étoile. Cette dernière est alors cachée partiellement ou complètement.... read more ❯
TONIGHT: NASA TESS exoplanet target for Unistellar eVscope users on March 7.
Dear Unistellar eVscope users, Since it was very cloudy last night in California, I thought I'd post another target since forecasts predict only partly cloudy skies tonight. Be sure to check your weather, and be especially careful for any rain, but if the stars align, then go get some exoplanet data!!! 😉 Background Information (skip to the observing directions, if you've seen this before) If you have not seen my previous posts on this topic, my name is Dan Peluso and I am doing my PhD in astrophysics with Franck Marchis (astronomer at the SETI Institute) and as a portion of my research I want to see if it is possible for any astronomy enthusiast around the world to coordinate with planet hunting scientists like us to help contribute to the search for planets around other stars (a.k.a. exoplanets). Currently, one of the best planet hunting missions in operations is NASA's Transiting Exoplanet Survey... read more ❯
March 6 Weekend Edition: Get your Unistellar eVscopes and help observe NASA TESS exoplanets!
Dear Unistellar eVscope users, It's time for another Unistellar eVscope exoplanet citizen science campaign. We would love your help observing some exoplanets, so if you want to join us in some planet hunting, then charge up your eVscopes and get ready because we need your help this weekend! Background Information (skip to the observing directions, if you've seen this before) If you have not seen my previous posts on this topic, my name is Dan Peluso and I am doing my PhD in astrophysics with Franck Marchis (astronomer at the SETI Institute) and as a portion of my research I want to see if it is possible for any astronomy enthusiast around the world to coordinate with planet hunting scientists like us to help contribute to the search for planets around other stars (a.k.a. exoplanets). Currently, one of the best planet hunting missions in operations is NASA's Transiting Exoplanet Survey Satellite (a.k.a. TESS). Although NASA's... read more ❯