Dr. Adeene Denton

@spacewhalerider.com

Planetary scientist, earth + space science historian, dancer/choreographer, part-time community radio DJ. (they/she) 🏳️‍🌈 adeenedenton.com

Crater Fact Friday ☄️DID YOU KNOW☄️ Venus lacks craters <~2km, due to its extremely dense atmosphere? Large craters that do form exhibit ejecta with sinuous flows, similar to lava flows, because surface rocks are easily melted by the high pressures and temperatures reached during the impact.

Magellan radar image of Balch Crater, Venus, originally designated Somerville Crater. This crater is one of the few examples of tectonically modified craters seen on Venus. The absence of such craters indicates a possible cessation of tectonic deformation on Venus at some point in history. Balch is located at 30° N, 283° W in Devana Chasma, Central Beta Regio. The crater was originally 37 kilometres in diameter. North is up.This 30-kilometer (18.6-mile) diameter crater, named Adivar crater for the Turkish educator and author Halide Adivar (1883-1964), is located just north of the western Aphrodite highland (9 degrees north latitude, 76 degrees east longitude). Surrounding the crater rim is ejected material which appears bright in the radar image due to the presence of rough fractured rock. A much broader area has also been affected by the impact, particularly to the west of the crater. Radar-bright materials, including a jet-like streak just west of the crater, extend for over 500 kilometers (310 miles) across the surrounding plains. A darker streak, in a horseshoe or paraboloidal shape, surrounds the bright area. Radar-dark (i.e., smooth) paraboloidal streaks were observed around craters in earlier Magellan images, but this is a rare bright crater streak. These unusual streaks, seen only on Venus, are believed to result from the interaction of crater materials (the meteoroid, ejecta, or both) and high-speed winds in the upper atmosphere. The precise mechanism that produces the streaks is poorly understood, but it is clear that the dense atmosphere of Venus plays an important role in the cratering process.Crater Isabella, with a diameter of 175 kilometers (108 miles), seen in this Magellan radar image, is the second largest impact crater on Venus. The feature is named in honor of the 15th Century queen of Spain, Isabella of Castile. Located at 30 degrees south latitude, 204 degrees east longitude, the crater has two extensive flow-like structures extending to the south and to the southeast. The end of the southern flow partially surrounds a pre-existing 40 kilometer (25 mile) circular volcanic shield. The southeastern flow shows a complex pattern of channels and flow lobes, and is overlain at its southeastern tip by deposits from a later 20 kilometer (12 mile) diameter impact crater, Cohn (for Carola Cohn, Australian artist, 1892-1964). The extensive flows, unique to Venusian impact craters, are a continuing subject of study for a number of planetary scientists. It is thought that the flows may consist of 'impact melt,' rock melted by the intense heat released in the impact explosion. An alternate hypothesis invokes 'debris flows,' which may consist of clouds of hot gases and both melted and solid rock fragments that race across the landscape during the impact event. That type of emplacement process is similar to that which occurs in violent eruptions on Earth, such as the 1991 Mount Pinatubo eruption in the Philippines.Magellan radar image of Wheatley crater on Venus. This 72 km diameter crater shows a radar bright ejecta pattern and a generally flat floor with some rough raised areas and faulting. The crater is located in Asteria Regio at 16.6N,267E.

🚨BREAKING: the Senate will vote in A FEW HOURS on a bill keeping NASA funded & political appointees out of science grants. Without it, the government could shut down, a 46% NASA science cut, and political appointees would override peer review. Use your voice. ⬇️ www.planetary.org/advocacy-act...

Advocacy Action Center

The Planetary Society is organizing a new space constituency that is educated, empowered, and loud.

planetary.org

Sustain a Palestinian-led grassroots, mutual aid project for displaced families in Jabalia refugee camp. The latest? Helping disabled kids with medical care! Plus food, water, tents, and much more. Every ounce helps. Give/find their link here. Hit “weekly”! chuffed.org/project/hope...

Keep Hope Alive: a Gaza Giving Circle

We are a team of volunteers in the US and UK, led by two sisters passionate about helping our friends on the ground keep their families and neighbors alive with food, water, & shelter. We saw that…

chuffed.org

One of my favourite things about anarchism is that the idea of free and voluntary society by cooperation rather than violence is so dangerous the popular media has had to repeatedly create fictional "anarchists" that are just stereotype of the most dangerous psychopath imaginable for deterrence.

Nate O@nateo.bsky.social · 3d ago

Anyone else remember Bond villain Renard from The World is Not Enough (1999) whose gimmick was he was shot in the head, survived, but the bullet was stuck in his head and was slowly moving through his brain, destroying his medulla oblongata, so over time he got superpowers of not feeling anything?

With one link, you can help six families + a camp of fifteen more survive. The latest needs? Several medical emergencies: hospital stays, medication, and more in a collapsed healthcare system. Click "weekly/monthly" on a coffee! chuffed.org/project/hope...

Keep Hope Alive: a Gaza Giving Circle

We are a team of volunteers in the US and UK, led by two sisters passionate about helping our friends on the ground keep their families and neighbors alive with food, water, & shelter. We saw that…

chuffed.org

This is a very serious problem for libraries, archives, and knowledge-keepers of all kinds. If you don’t control access to your collections, *you do not have collections.* If we do not have permanent access to records, stories, & sources of knowledge then our histories and memories are not our own.

Shannon Mattern@shannonmattern.bsky.social · 3d ago

"In 2022, Wiley removed over 1,300 ebooks from academic library collections; [they said] perpetual access is not an option for subscribed content. In 2025, Clarivate,... announced they would stop offering libraries perpetual access licenses for ebooks and primary-source digital collections."

I think we can agree that AI detectors are out. But universities are ignoring the fact that faculty cannot really out-design assessments to meet the challenges of this moment. We need sustained institutional support to be the best teachers we can be, and we aren't getting it.

Inside Higher Ed @insidehighered.com · 4d ago

AI Detectors Are Out, New Assessments Are In A growing number of universities have prohibited AI detectors, arguing they are ‘unreliable’ indicators of cheating. But where does that leave faculty, who know all too well that cheating is rampant in the age of AI? https://bit.ly/4wGitF7 #EDUSky

A photo illustration of three humanoid robots standing in front of a college entrance gateway.

We will never give up on them. Little girls Remas & Toleen need sustained support for food, shelter, other necessities. A 5 you click “weekly/monthly” on is ALL I ask. Please do not give more! Give/find their link here: chuffed.org/project/hope...

Keep Hope Alive: a Gaza Giving Circle

We are a team of volunteers in the US and UK, led by two sisters passionate about helping our friends on the ground keep their families and neighbors alive with food, water, & shelter. We saw that…

chuffed.org

President Trump and OK Gov Stitt are trying to put a $4 billion aluminum smelter on the Muscogee Reservation. But the tribe opposes the project–which would pollute the air, contaminate water, harm wildlife, and disrupt the energy grid. www.kosu.org/muscogee-nat...

Muscogee Nation opposes Inola smelter intended within reservation

The Muscogee National Council unanimously approved a resolution Saturday opposing aluminum smelters, including a large, controversial project intended for Inola.

kosu.org

🚨URGENT ADVOCACY ACTION - We can pause OMB's harmful rewrite of grant rules that insert political appointees into the funding process, but only if enough of us speak up THIS WEEK. 🚨 This is our best shot before senators leave for August recess. Send your letter: www.planetary.org/advocacy-act...

Advocacy Action Center

The Planetary Society is organizing a new space constituency that is educated, empowered, and loud.

planetary.org

Spark Space provides internet to freelancers to connect to remote work and rebuild their careers, while also offering community classes and spaces for students to study. Help support their work by kicking in $5 or $10, and doing so weekly if you can:

🇵🇸 Gaza Needs Your Support: Help Build a Lifeline for Students and Remote Workers!

In Gaza, war has destroyed homes, blocked roads, and left countless people without work. Yet, amidst the rubble, hope remains. Students and remote workers face daily struggles—power outages, broken…

chuffed.org